Insects - حشرات PDF

University of Tabuk Faculty of science Department of Biology General Entomology (BIO 1302) Chapter 5 Abdomen (Adult and Immature Stages) Academic Year 1446 First semester University of Tabuk Faculty of science Department of Biolo...

University of Tabuk Faculty of science Department of Biology General Entomology (BIO 1302) Chapter 5 Abdomen (Adult and Immature Stages) Academic Year 1446 First semester University of Tabuk Faculty of science Department of Biology General Entomology (BIO 1302) Chapter 5 Abdomen (Adult and Immature Stages) Academic Year 1446 First semester  Outline ‫اﻟﺒﻨﻴﺔ اﻷﺳﺎﺳﻴﺔ ﻟﻠﺒﻄﻦ‬ Basic structure of abdomen ‫أﺟﺰاء اﻟﺒﻄﻦ‬ ‫ﻣﻠﺤﻖ اﻟﺒﻄﻦ‬ Abdominal segments ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ ﻗﺒﻞ اﻟﺘﻨﺎﺳﻠﻴﺔ ﰲ اﳊﺸﺮات ﻋﺪﳝﺔ اﻷﺟﻨﺤﺔ‬.1 ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ ﻟﺪى اﻟﺒﺎﻟﻐﲔ اﺠﻤﻟﻨﺤﲔ‬.2 Abdominal appendage ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ ﰲ اﳊﺸﺮات ﻏﻴﺮ اﻟﻨﺎﺿﺠﺔ‬.3 1. Pregenital abdominal appendages in wingless insects 2. Abdominal appendages in winged adults 3. Abdominal appendages in immature insects University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Basic structure of abdomen  Each segment has a dorsal Tergum, ventral Sternum and two lateral Pleura which the respiratory spiracles are usually located.  In many insect abdomen less strongly sclerotized than head or thorax  Segments are connected by a stretchable membrane Pleural membrane University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester.‫ وﻗﺪ ُﻓﻘﺪ اﳉﺰء اﳊﺎدي ﻋﺸﺮ ﰲ أﻛﺜﺮ اﺠﻤﻟﻤﻮﻋﺎت ﺗﻘﺪًﻣﺎ‬،‫ ﻋﻠﻰ اﻟﺮﻏﻢ ﻣﻦ أن اﳉﺰء اﻟﻌﺎﺷﺮ واﳊﺎدي ﻋﺸﺮ ﻋﺎدًة ﻣﺎ ﻳﻜﻮﻧﺎن ﺻﻐﻴﺮﻳﻦ وﻏﻴﺮ ﻣﺮﺋﻴﲔ ﻣﻦ اﳋﺎرج‬،‫ ﺟﺰًءا‬11 ‫ﻳﺘﻜﻮن اﻟﺒﻄﻦ ﰲ اﻷﺻﻞ ﻣﻦ‬ ‫ﻳﺘﻢ ﺗﻌﺪﻳﻞ اﻷﺟﺰاء اﻟﺒﻄﻨﻴﺔ اﳋﻠﻔﻴﺔ ﻟﻠﺘﺰاوج ووﺿﻊ اﻟﺒﻴﺾ‬. Basic structure of abdomen ‫ﲢﺘﻮي ﻋﻠﻰ اﳉﻬﺎز اﻟﻬﻀﻤﻲ ﻟﻠﺤﺸﺮة‬ ‫واﻷﻋﻀﺎء اﻟﺘﻨﺎﺳﻠﻴﺔ‬  The abdomen is composed primitively of 11 segments, although the tenth and eleventh segments are usually small and not externally visible, and the eleventh segment has been lost in most advanced groups.  The posterior abdominal segments are modified for mating and oviposition.  It contains the insect's digestive tract and reproductive organs. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal segments A. Visceral segments: The first seven segments, Similar, Unspecialized, Visible , Distinct. B. Genital segments: segment 9 in males and 8-9 in females are modified for reproductive functions. C. post-genital segments: The segment 10 (and vestigial 11). ‫اﳌﻘﺎﻃﻊ اﻟﺒﻄﻨﻴﺔ‬.‫ ﳑﻴﺰة‬،‫ ﻣﺮﺋﻴﺔ‬،‫ ﻏﻴﺮ ﻣﺘﺨﺼﺼﺔ‬،‫ ﻣﺘﺸﺎﺑﻬﺔ‬،‫ أول ﺳﺒﻊ ﻣﻘﺎﻃﻊ‬:‫ اﳌﻘﺎﻃﻊ اﳊﺸﻮﻳﺔ‬.‫أ‬.‫ ﰲ اﻹﻧﺎث ﻣﻌﺪل ﻟﻠﻮﻇﺎﺋﻒ اﻹﳒﺎﺑﻴﺔ‬9-8‫ ﰲ اﻟﺬﻛﻮر و‬9 ‫ اﳌﻘﻄﻊ‬:‫ اﳌﻘﺎﻃﻊ اﻟﺘﻨﺎﺳﻠﻴﺔ‬.‫ب‬ (11 ‫ )واﻷﺟﺰاء اﻷﺛﺮﻳﺔ‬10 ‫ اﳌﻘﻄﻊ‬:‫ اﳌﻘﺎﻃﻊ ﻣﺎ ﺑﻌﺪ اﻟﺘﻨﺎﺳﻠﻴﺔ‬.‫ج‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 1. Pregenital abdominal appendages in wingless insects 2. Abdominal appendages in winged adults 3. Abdominal appendages in immature insects ‫اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ‬ ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ ﻗﺒﻞ اﻟﺘﻨﺎﺳﻠﻴﺔ ﰲ اﳊﺸﺮات ﻋﺪﳝﺔ اﻷﺟﻨﺤﺔ‬.1 ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ ﰲ اﳊﺸﺮات اﻟﺒﺎﻟﻐﺔ اﺠﻤﻟﻨﺤﺔ‬.2 ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ ﰲ اﳊﺸﺮات ﻏﻴﺮ اﻟﻨﺎﺿﺠﺔ‬.3 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 1. Pregenital abdominal appendages in wingless insects a) Styli (Stylus : Singular): ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ اﻟﺘﻨﺎﺳﻠﻴﺔ ﰲ اﳊﺸﺮات ﻋﺪﳝﺔ اﻷﺟﻨﺤﺔ‬.1  Found on the ventral side of the abdomen of silverfish. :(‫ ﻣﻔﺮد‬:‫أ( اﻹﺑﺮ )اﻹﺑﺮة‬.‫ ﺗﻮﺟﺪ ﻋﻠﻰ اﳉﺎﻧﺐ اﻟﺒﻄﻨﻲ ﻣﻦ ﺑﻄﻦ اﻟﺴﻤﻜﺔ اﻟﻔﻀﻴﺔ‬-  Help in locomotion ( e.g., Silverfish). ‫ اﻟﺴﻤﻜﺔ اﻟﻔﻀﻴﺔ‬،‫ ﺗﺴﺎﻋﺪ ﰲ اﳊﺮﻛﺔ )ﻋﻠﻰ ﺳﺒﻴﻞ اﳌﺜﺎل‬- University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ اﻟﺘﻨﺎﺳﻠﻴﺔ ﰲ اﳊﺸﺮات ﻋﺪﳝﺔ اﻷﺟﻨﺤﺔ‬.1 (‫ اﻟﻜﻮﻟﻴﻤﺒﻮﻻ‬،‫ ﺗﻌﻤﻞ ﻛﻌﻀﻮ اﻟﺘﺼﺎق )ﻋﻠﻰ ﺳﺒﻴﻞ اﳌﺜﺎل‬.‫ ﻋﻠﻰ اﳉﺎﻧﺐ اﻟﺒﻄﻨﻲ ﻟﻠﻘﻄﻌﺔ اﻟﺒﻄﻨﻴﺔ اﻷوﻟﻰ‬:‫ب( اﻟﻜﻮﻟﻔﻮر أو اﻷﻧﺒﻮب اﻟﺒﻄﻨﻲ أو وﺗﺪ اﻟﻐﺮاء‬ Abdominal appendage.(‫ اﻟﻜﻮﻟﻴﻤﺒﻮﻻ‬،‫ ﻋﻠﻰ اﳉﺎﻧﺐ اﻟﺒﻄﻨﻲ ﻟﻠﻘﻄﻌﺔ اﻟﺒﻄﻨﻴﺔ اﻟﺜﺎﻟﺜﺔ )ﻋﻠﻰ ﺳﺒﻴﻞ اﳌﺜﺎل‬:‫ج( اﻟﺮﻳﺘﻴﻨﺎﻛﻮﻟﻮم أو اﻟﺘﻴﻨﺎﻛﻮﻟﻮم أو اﳌﺸﺒﻚ‬ ‫ ﻳﻮﺟﺪ ﻋﻠﻰ ﺑﻄﻦ اﻟﻘﻄﻌﺔ اﻟﺒﻄﻨﻴﺔ اﻟﺮاﺑﻌﺔ‬.Y " " ‫ ﻋﻀﻮ ﻋﻠﻰ ﺷﻜﻞ ﺣﺮف‬:‫د( اﻟﻔﻮرﻛﻮﻻ أو اﻟﻔﻮرﻛﺎ‬ 1. Pregenital abdominal appendages in wingless insects b) Collophore or ventral tube or glue peg: on the ventral side of the 1st abdominal segment. It serve as an organ of adhesion (E.g., Collembola) C) Retinaculum or tenaculum or catch: On the ventral side of the 3rd abdominal segment (E.g., Collembola). D) Furcula or Furca: 'Y' shaped organ. It is present on the venter of 4th abdominal segment. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 2. Abdominal appendages in winged adults ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ A. Cornicles: ‫ اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ ﰲ اﻟﺒﺎﻟﻐﲔ اﺠﻤﻟﻨﺤﲔ‬.2 :‫ اﻟﻘﺮﻳﻨﺎت‬.‫أ‬  Pair of short tubes ‫زوج ﻣﻦ اﻷﻧﺎﺑﻴﺐ اﻟﻘﺼﻴﺮة‬  Secrete defensive wax fluid ‫ﺗﻔﺮز ﺳﺎﺋﻞ ﺷﻤﻌﻲ دﻓﺎﻋﻲ‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 2. Abdominal appendages in winged adults B. Caudal breathing tube: It consists of two grooved filaments closely applied to each other forming a hollow tube at the apex of abdomen. e.g., water scorpion. ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ ‫ اﻟﺰواﺋﺪ اﻟﺒﻄﻨﻴﺔ ﰲ اﻟﺒﺎﻟﻐﲔ اﺠﻤﻟﻨﺤﲔ‬.2 ‫ ﻳﺘﻜﻮن ﻣﻦ ﺧﻴﻄﲔ‬:‫ أﻧﺒﻮب اﻟﺘﻨﻔﺲ اﻟﺬﻳﻠﻲ‬.‫ب‬ ‫ﻣﺤﺰزﻳﻦ ﻣﻠﺘﺼﻘﲔ ﺑﺒﻌﻀﻬﻤﺎ اﻟﺒﻌﺾ ﺑﺸﻜﻞ وﺛﻴﻖ‬.‫ﻟﻴﺸﻜﻼ أﻧﺒﻮًﺑﺎ ﻣﺠﻮًﻓﺎ ﰲ ﻗﻤﺔ اﻟﺒﻄﻦ‬.‫ ﻋﻘﺮب اﳌﺎء‬،‫ﻋﻠﻰ ﺳﺒﻴﻞ اﳌﺜﺎل‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 2. Abdominal appendages in winged adults ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ C. Cerci : They are sensory in function. ‫ اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ ﰲ اﻟﺒﺎﻟﻐﲔ اﺠﻤﻟﻨﺤﲔ‬.2 C. Cerci: ‫وﻫﻲ ﺣﺴﻴﺔ ﰲ وﻇﻴﻔﺘﻬﺎ‬.  Long and many segmented :- e.g. Mayfly ‫ ﻣﺜﻞ ذﺑﺎﺑﺔ ﻣﺎﻳﻮ‬-:‫ﻃﻮﻳﻠﺔ وﻣﺘﻌﺪدة اﻷﺟﺰاء‬  Long and unsegmented :- e.g. Cricket ‫ ﻣﺜﻞ ﺻﺮﺻﻮر اﻟﻠﻴﻞ‬-:‫ﻃﻮﻳﻠﺔ وﻏﻴﺮ ﻣﻘﺴﻤﺔ‬ ‫ ﻣﺜﻞ اﻟﺼﺮﺻﻮر‬-:‫ﻗﺼﻴﺮة وﻣﺘﻌﺪدة اﻷﺟﺰاء‬  Short and many segmented :- e.g. Cockroach ‫ ﻣﺜﻞ اﳉﻨﺪب‬-:‫ﻗﺼﻴﺮة وﻏﻴﺮ ﻣﻘﺴﻤﺔ‬  Short and unsegmented :- e.g. Grasshopper ‫ ﻣﺜﻞ ﺣﺸﺮة أﺑﻮ ﻣﻘﺺ‬-:‫ﻣﺘﺼﻠﺒﺔ وﻣﻠﺘﻮﻳﺔ ﻣﺜﻞ‬. Cerci ‫ وﻧﺸﺮ اﻷﺟﻨﺤﺔ واﳌﻐﺎزﻟﺔ‬،‫ وﺻﻴﺪ اﻟﻔﺮاﺋﺲ‬،‫ﻣﻔﻴﺪة ﰲ اﻟﺪﻓﺎع‬  Sclerotised and forceps like : e.g. Earwig. Cerci are useful in defense, prey capture, unfolding wings and courtship. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 2. Abdominal appendages in winged adults Mayfly Cricket Cockroach File:Earwig wing1.jpg Cerci Grasshopper Earwig University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 2. Abdominal appendages in winged adults D. Anal styli: A pair of short unsegmented structure found at the end of the abdomen of male cockroach. They are used to hold the female during copulation. ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ ‫ اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ ﰲ اﻟﺒﺎﻟﻐﲔ اﺠﻤﻟﻨﺤﲔ‬.2 ‫ زوج ﻣﻦ اﻟﻬﻴﺎﻛﻞ اﻟﻘﺼﻴﺮة ﻏﻴﺮ‬:‫ اﻹﺑﺮ اﻟﺸﺮﺟﻴﺔ‬.‫د‬.‫اﺠﻤﻟﺰأة اﳌﻮﺟﻮدة ﰲ ﻧﻬﺎﻳﺔ ﺑﻄﻦ اﻟﺼﺮﺻﻮر اﻟﺬﻛﺮ‬ ‫ُﺗﺴﺘﺨﺪم ﻹﻣﺴﺎك اﻷﻧﺜﻴﺄﺛﻨﺎء اﻟﺘﺰاوج‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 2. Abdominal appendages in winged adults E. Ovipositor: The egg laying organ found in female insect is called ovipositor.  Short and horny: e.g., Short horned grasshopper  Long and sword like e.g., Katydid, long horned grasshopper  Needle like e.g., Cricket ‫ ﺟﻨﺪب ﻗﺼﻴﺮ اﻟﻘﺮن‬،‫ ﻋﻠﻰ ﺳﺒﻴﻞ اﳌﺜﺎل‬:‫ﻗﺼﻴﺮ وﻗﺮﻧﻲ‬  Ovipositor modified into sting : e.g., Worker honeybee. ! ‫ ﺟﻨﺪب ﻃﻮﻳﻞ اﻟﻘﺮن‬،‫ ﻛﺎﺗﻴﺪﻳﺪ‬،‫ﻃﻮﻳﻞ وﺳﻴﻒ ﻣﺜﻞ ﻋﻠﻰ ﺳﺒﻴﻞ اﳌﺜﺎل‬ ‫ اﻟﻜﺮﻳﻜﻴﺖ‬،‫إﺑﺮة ﻣﺜﻞ ﻋﻠﻰ ﺳﺒﻴﻞ اﳌﺜﺎل‬ ! ‫ ﰎ ﺗﻌﺪﻳﻞ‬Ovipositor ‫ ﻧﺤﻞ اﻟﻌﺴﻞ اﻟﻌﺎﻣﻞ‬،‫ ﻋﻠﻰ ﺳﺒﻴﻞ اﳌﺜﺎل‬:‫إﻟﻰ ﻟﺪﻏﺔ‬. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  long horned grasshopper Abdominal appendage 2. Abdominal appendages in winged adults Katydid Cricket University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 2. Abdominal appendages in winged adults F. Male genitalia: The two main organs in male external genitalia are:  The aedeagus: used to transfer sperms from male to female genital duct  A pair of claspers: used for holding the female during coupulaion. ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ ‫ اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ ﰲ اﻟﺒﺎﻟﻐﲔ اﺠﻤﻟﻨﺤﲔ‬.2 F. ‫اﻷﻋﻀﺎء اﻟﺘﻨﺎﺳﻠﻴﺔ اﻟﺬﻛﺮﻳﺔ‬: :‫اﻟﻌﻀﻮان اﻟﺮﺋﻴﺴﻴﺎن ﰲ اﻷﻋﻀﺎء اﻟﺘﻨﺎﺳﻠﻴﺔ اﳋﺎرﺟﻴﺔ ﻟﻠﺬﻛﻮر ﻫﻤﺎ‬ ‫ ﺗﺴﺘﺨﺪم ﻟﻨﻘﻞ اﳊﻴﻮاﻧﺎت اﳌﻨﻮﻳﺔ ﻣﻦ‬:‫اﻟﻘﻨﺎة اﻟﺘﻨﺎﺳﻠﻴﺔ اﳋﺎرﺟﻴﺔ‬ ‫اﻟﺬﻛﺮ إﻟﻰ اﻷﻧﺜﻰ‬ ‫ ﺗﺴﺘﺨﺪم ﳊﻤﻞ اﻷﻧﺜﻰ أﺛﻨﺎء اﻻﻗﺘﺮان‬:‫زوج ﻣﻦ اﳌﻼﻗﻂ‬. aedeagus University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 3. Abdominal appendages in immature insects A. Tracheal gills: ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ ‫ اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ ﰲ اﳊﺸﺮات ﻏﻴﺮ اﻟﻨﺎﺿﺠﺔ‬.3  lateral gills: e.g., naiads of mayfly :‫ ﺧﻴﺎﺷﻴﻢ اﻟﻘﺼﺒﺔ اﻟﻬﻮاﺋﻴﺔ‬.‫أ‬ ‫ ﻣﺜﻞ ﺣﻮرﻳﺎت اﻟﺒﺤﺮ ﰲ ذﺑﺎﺑﺔ ﻣﺎﻳﻮ‬:‫ﺧﻴﺎﺷﻴﻢ ﺟﺎﻧﺒﻴﺔ‬ ‫ ﻣﺜﻞ ﺣﻮرﻳﺎت اﻟﺒﺤﺮ ﰲ ذﺑﺎﺑﺔ اﻟﻴﻌﺴﻮب‬:(‫ﺧﻴﺎﺷﻴﻢ ذﻳﻠﻴﺔ )ﺻﻔﻴﺤﻴﺔ‬  Caudal gills (lamellate): e.g., naiad of damselfly ‫ﺧﻴﺎﺷﻴﻢ ﻣﺴﺘﻘﻴﻤﻴﺔ )ﺗﻮﺟﺪ اﳋﻴﺎﺷﻴﻢ داﺧﻞ اﻟﺒﻄﻦ ﰲ ﻛﻴﺲ ﻣﺜﻞ‬ ‫ ﻣﺜﻞ ذﺑﺎﺑﺔ اﻟﻴﻌﺴﻮب‬:(‫اﳌﺴﺘﻘﻴﻢ‬  Rectal gills (gills are retained within the abdomen in a pouch like rectum ): e.g., dragonfly naiads of mayfly dragonfly naiad of damselfly University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Abdominal appendage 3. Abdominal appendages in immature insects B. Anal papillae: A group of four papillae surrounds the anus in mosquito larvae. These papillae are concerned with salt regulation. ‫اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ‬ ‫ اﻟﺰاﺋﺪة اﻟﺒﻄﻨﻴﺔ ﰲ اﳊﺸﺮات ﻏﻴﺮ اﻟﻨﺎﺿﺠﺔ‬.3 ‫ ﻣﺠﻤﻮﻋﺔ ﻣﻦ أرﺑﻊ ﺣﻠﻴﻤﺎت ﲢﻴﻂ ﺑﺎﻟﺸﺮج ﰲ‬:‫ اﳊﻠﻴﻤﺎت اﻟﺸﺮﺟﻴﺔ‬.‫ب‬ ‫ ﻫﺬه اﳊﻠﻴﻤﺎت ﻣﻌﻨﻴﺔ ﺑﺘﻨﻈﻴﻢ اﳌﻠﺢ‬.‫ﻳﺮﻗﺎت اﻟﺒﻌﻮض‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester University of Tabuk Faculty of science Department of Biology ‫ﳕﻮ اﳊﺸﺮات وﺗﻄﻮرﻫﺎ‬ General Entomology (BIO 1302) Chapter 6 Insect Growth and Development Academic Year 1446 First semester  Outline Metamorphosis Growth Insect body wall and molting Insect Eggs Types of larvae Types of pupae University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Metamorphosis  The term “metamorphosis” refers to change in form during development.  Some group of insects do not undergo metamorphosis  Other groups develop through incomplete, gradual , or complete metamorphosis University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Type of Metamorphosis in insect 1. Ametabolous Development (No Metamorphosis) 2. Hemimetabolous Development (Incomplete Metamorphosis) 3. Paurometabolous Development (Gradual Metamorphosis) 4. Holometabola Development (Complete metamorphosis) ‫أﻧﻮاع اﻟﺘﺤﻮل ﰲ اﳊﺸﺮات‬ (‫ اﻟﺘﻄﻮر اﻷﻳﻀﻲ )ﻻ ﲢﻮل‬.1 (‫ اﻟﺘﻄﻮر اﻷﻳﻀﻲ اﳉﺰﺋﻲ )اﻟﺘﺤﻮل ﻏﻴﺮ اﻟﻜﺎﻣﻞ‬.2 (‫ اﻟﺘﻄﻮر اﻷﻳﻀﻲ اﻟﻜﺎﻣﻞ )اﻟﺘﺤﻮل اﻟﺘﺪرﻳﺠﻲ‬.3 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester (‫ اﻟﺘﻄﻮر اﻷﻳﻀﻲ اﻟﻜﺎﻣﻞ )اﻟﺘﺤﻮل اﻟﻜﺎﻣﻞ‬.4  Type of Metamorphosis in insect 1. Ametabolous Development (No Metamorphosis):  The no-metamorphosis model is found in primitively wingless insects (subclass Apterygota; E.g., Thysanura: silverfish).  The younger emerging from the egg is exactly similar to adult except smaller in size with immature reproductive organs and external genitalia University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Type of Metamorphosis in insect 1. Ametabolous Development (No Metamorphosis): University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Type of Metamorphosis in insect 2. Hemimetabolous Development (Incomplete Metamorphosis):  Insect with incomplete metamorphosis emerge from egg as immature naiads that develop into adults.  Naiads are aquatic and have gills.  E.g., mayflies, dragonflies University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Type of Metamorphosis in insect 2. Hemimetabolous Development (Incomplete Metamorphosis): University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Type of Metamorphosis in insect 3. Paurometabolous Development (Gradual Metamorphosis)  Primarily terrestrial.  The immature nymphs and adult occupy the same habitats and feed on the same food  There is a gradual change in size and body proportions and gradual development of wings and genital structures from one molt to the next.  E.g. Grasshoppers, cockroaches, University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Type of Metamorphosis in insect 3. Paurometabolous Development (Gradual Metamorphosis) University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Type of Metamorphosis in insect 4. Holometabola Development (Complete metamorphosis)  Occurs in the more advanced orders of insect.  Comprising four stages egg, larva, pupa and adult. Larva molts several times, including a series of instars, to become a fully pupa.  In some species with complete metamorphosis, the adult feed on the same host as larvae, other feed on different hosts, and some survive on nutrients stored in the fat body during the larval stage. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Type of Metamorphosis in insect 4. Holometabola Development (Complete metamorphosis) University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Growth in insects  After hatching, the small immature insects feed and grow in size within the limitations of exoskeleton. The exoskeleton is hardened, relatively inelastic, nonliving tissue that does not grow.  The immature insect sheds the obstructive exoskeleton and develops another exoskeleton that allows the insect to increase in size. This process is called molting. Most insect molt four to eight times.  Each stage between molts is called an instar. For example, the first instar is between hatching and the first molt, the second instar is between the first and second molt University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Growth in insects University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Growth in insects  Instar number vary by species but are usually the same within species.  Temperature, humidity, quality and quantity of food, population, density, and sex can affect the number of instars.  Most insect species do not molt after reaching the adult stage. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Insect body wall and molting  The body wall of insect is composed of three principal layers: 1. The cuticle 2. Epidermis 3. basement membrane. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Insect body wall and molting 1- The cuticle:  The cuticle is an outer layer which contains a characteristic chemical compounds called chitin, proteins and pigments.  The cuticle is made up of three principal layers: epicuticle, exocuticle and endocuticle. The exo- and endo- cuticle together referred as procuticle. ‫ﺟﺪار ﺟﺴﻢ اﳊﺸﺮات واﻻﻧﺴﻼخ‬ :‫ اﻟﺒﺸﺮة‬-1 ‫اﻟﺒﺸﺮة ﻫﻲ ﻃﺒﻘﺔ ﺧﺎرﺟﻴﺔ ﲢﺘﻮي ﻋﻠﻰ ﻣﺮﻛﺒﺎت ﻛﻴﻤﻴﺎﺋﻴﺔ ﳑﻴﺰة ﺗﺴﻤﻰ اﻟﻜﻴﺘﲔ واﻟﺒﺮوﺗﻴﻨﺎت واﻷﺻﺒﺎغ‬. ‫ اﻟﺒﺸﺮة اﻷوﻟﻴﺔ‬,‫ ﻳﺸﺎر إﻟﻰ اﻟﺒﺸﺮة اﳋﺎرﺟﻴﺔ واﻟﺒﺸﺮة اﻟﺪاﺧﻠﻴﺔ ﻣﻌًﺎ ﺑﺎﺳﻢ‬.‫ اﻟﺒﺸﺮة اﳋﺎرﺟﻴﺔ واﻟﺒﺸﺮة اﻟﺪاﺧﻠﻴﺔ‬:‫ﺗﺘﻜﻮن اﻟﺒﺸﺮة ﻣﻦ ﺛﻼث ﻃﺒﻘﺎت رﺋﻴﺴﻴﺔ‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Insect body wall and molting 3- Epidermis: All the epidermal cells are glandular and secrete cuticle and the enzymes involved in production and digestion of old cuticle during moulting. 4- Basement membrane: It is the basal part of the body wall formed from degenerated epidermal cells and appear as non-living amorphous (shapeless) granular layer of integument. ‫ﺟﺪار ﺟﺴﻢ اﳊﺸﺮة واﻻﻧﺴﻼخ‬.‫ ﺟﻤﻴﻊ ﺧﻼﻳﺎ اﻟﺒﺸﺮة ﻏﺪﻳﺔ وﺗﻔﺮز اﻟﺒﺸﺮة واﻻﻧﺰﳝﺎت اﻟﺘﻲ ﺗﺸﺎرك ﰲ إﻧﺘﺎج وﻫﻀﻢ اﻟﺒﺸﺮة اﻟﻘﺪﳝﺔ أﺛﻨﺎء اﻻﻧﺴﻼخ‬:‫ اﻟﺒﺸﺮة‬-3 ‫ ﻫﻮ اﳉﺰء اﻟﻘﺎﻋﺪي ﻣﻦ ﺟﺪار اﳉﺴﻢ اﳌﺘﻜﻮن ﻣﻦ ﺧﻼﻳﺎ اﻟﺒﺸﺮة اﳌﺘﺤﻠﻠﺔ وﻳﻈﻬﺮ ﻛﻄﺒﻘﺔ ﺣﺒﻴﺒﻴﺔ ﻏﻴﺮ ﺣﻴﺔ ﻏﻴﺮ ﻣﺘﺒﻠﻮرة )ﻋﺪﳝﺔ اﻟﺸﻜﻞ( ﻣﻦ اﻟﻐﻼف اﳋﺎرﺟﻲ‬:‫ اﻟﻐﺸﺎء اﻟﻘﺎﻋﺪي‬-4 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Insect body wall and molting Moulting is a complex process which involve 3 process: 1. Apolysis 2. Ecdysis 3. Sclerotization University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  The Steps of Molting Process  Exuvial space: the area between the cuticle and epidermis; fills with a molting gel that contains inactive enzymes including a chitinase and proteases for digesting the old cuticle. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  The Steps of Molting Process  The epidermal cells secrete a new outer epicuticle (lipoprotein: cuticulin)  The activation of the enzyme in the molting gel, now called the molting fluid;  The molting fluid begin the digestion of the old unsclerotized endocuticle;  The epidermal cells begin to secrete the new procuticle; University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  The Steps of Molting Process  Formation of the new epicuticle  Absorption of the molting fluid  Ecdysis: induced by eclosion hormone. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Insect Eggs  The form of eggs have various shapes.  Insect lay their eggs singly, whereas such as preying mantides lay masses that contain hundreds of eggs. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Insect Eggs  The favorable oviposition sites can vary considerably from one insect species to another.  Many weevils, saw-flies and dark beetle deposit their eggs within plant tissue.  Many beetles and grasshopper lay their eggs in the ground University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Insect Eggs  Aquatic insects normally deposit their eggs in the water, but the eggs are often attached to some type of substrate.  Parasitic insects, such as wasp normally lay their eggs in or on suitable host.  Females of most insect species lay eggs but those of flesh flies and many aphids give birth to live immatures University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Types of larva  There are three main types of insect larvae namely: 1. Oligopod: Thoracic legs are well developed. Abdominal legs are absent (e.g., larvae of ladybird beetle) 2. Polypod: The larva possess well defined segmentation of the body with three pairs of thoracic legs, 2-5 pairs of abdominal legs (3rd , 4th , 5th , 6th and 10th abdominal segment. They are phytophagous and destructive (e.g., Larvae of moth's ad butterflies) 3. Apodous: They are larvae without appendages for locomotion (e.g., larva of house fly) University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Types of larva Oligopod Polypod Apodous larvae of ladybird beetle Larvae of moth's ad butterflies larva of house fly University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Types of Pupa  There are three main types of pupae: 1. Obtect : The pupae have appendages which are firmly pressed against the body and the pupa is highly chitinized (e.g., moth pupa). 2. Exarate : The pupae have appendages which are free without any secondary attachment to the body (e.g.,Pupa of rhinoceros beetle). 3. Coarctate : The pupa remain enclosed in a puparium formed by the last larval skin and the pupa looks like a capsule or barrel (e.g., Fly pupa) University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Types of Pupa ‫ﺷﻜﺮا ﻳﻠﺠﺄ اﷲ!ش‬ Obtect Exarate Coarctate University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  University of Tabuk Faculty of science Department of Biology General Entomology (BIO 1302) Chapter 7 Internal Anatomy (Digestive System & Circulatory System) Academic Year 1446 First semester  Outline – Part I (Digestive System) Insect digestive system Alimentary canal Digestion Absorption of the digested food University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Alimentary canal  Consists usually of a long straight tube running from the mouth to the anus  It is divided into: Foregut (stomodeum) Midgut (mesenteron) Hindgut (proctodeum) University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Foregut (gastric caeca) Midgut Hindgut Alimentary canal of Periplaneta americana University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Alimentary canal  Consists usually of a long straight tube running from the mouth to the anus  It is divided into: Foregut (stomodeum) Midgut (mesenteron) Hindgut (proctodeum) University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Salivary glands  Behind the mouth are the salivary glands.  These secrete saliva - a watery fluid that lubricates the food and contains a enzymes to begin the processes of digestion or liquefaction of food. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Salivary glands  Salivary glands may be modified:  In carnivorous insects, the saliva is composed entirely of digestive enzymes.  In Lepidopteran caterpillars and Caddisfly larvae, they have been converted to the production of silk University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  1. Foregut (stomodeum)  Typically, the foregut is subdivided into a pharynx, an esophagus and a crop (food storage area), and in insects that ingest solid food there is often a grinding organ, the proventriculus (or gizzard). University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  1. Foregut (stomodeum)  The primary function of the foregut is to begin the breakdown of food particles and transport them to the next region, the midgut University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  1. Foregut (stomodeum) The foregut and the midgut are separated by the stomodeal or cardiac valve. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  2. Midgut (mesenteron)  It is relatively narrower and shorter than the foregut  The midgut is composed of the gastric caeca and the ventriculus (stomach).  Stomach (= ventriculus) is the area of most active digestion. It lies between the gastric caeca and Malpighian tubules. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester 2. Midgut (mesenteron) Gastric caeca: a series of stubby pointed tubes leading off from the stomach. Serve to increase the surface area of the midgut for secretion of digestive enzymes and absorption of useful products from the partially digested food.  2. Midgut (mesenteron) The useful proteins, vitamins and fats that are released by the digestive processes pass across the wall of the midgut into the body cavity. The midgut is lined with a peritrophic membrane (PM). The PM is a semi-permeable membrane of protein and chitin that allows the passage of liquids and dissolved substances to the midgut wall while preventing the passage of solid food particles. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  3. Hindgut (proctodeum)  It is usually differentiated into the pylorus, ileum (intestines ) and rectum  The pylorus is the first part of the hindgut and from it the Malpighian tubules (excretory in function) often arise. The pylorus sometimes forms a valve between the midgut and hindgut.  The intestines, where much of the diffusion into the insect's body occurs.  The rectum compresses the undigested food and waste products and extracts more water if necessary before it is passed out through the anus as faces. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  3. Hindgut (proctodeum) The midgut and hindgut are separated by the pyloric valve. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Digestion  Food ingested by insects is macromolecular ( polysaccharides, proteins , lipids ( phospholipids, glycerides, glycolipids)).  Small molecules can only pass into tissues  Large molecules must be broken down into a component of suitable size before absorption occurs.  Enzymes concerned with digestion in saliva and in midgut secretions.  Also, microorganisms in the gut may facilitate digestion University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Digestion  In fluid feeders, digestion may begin before the food is ingested through the injection or regurgitation of enzymes on to the food, or in foregut but in general most digestion occurs in the midgut where most of the enzymes are produced.  In insects having biting and chewing type of mouthparts, food is masticated not only in the buccal cavity but also in the proventriculus.  Digestion takes place by a series of progressive enzymatically catalyzed steps, each producing a simpler substance until molecules of absorbable size or nature are produced. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Absorption of the digested food  The midgut is the major site of absorption.  In hindgut only reabsorption of urine components occur while in foregut no absorption takes place. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Outline – Part II (Circulatory System)  Organs of Circulatory system  Heartbeat  Circulation  Factors affecting the rate of the heartbeat  Hemolymph  Insect Blood Cells (Hemocytes)  Functions of Plasma University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Circulatory system of Insects Insects have an open circulatory system, the blood (hemolymph) occupy all the body cavity (haemocoel), the internal organs and tissues are exposed freely to it. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 1. Sinuses and diaphragms. 2. Dorsal blood vessel 3. Accessory pulsatile organs. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 1. Sinuses and diaphragms.  The haemocoel is divided into three major sinuses by fibro-muscular septa or diaphragms The three major sinuses. a. Pericardial Sinus- Dorsal b. Perivisceral Sinus- Middle c. Perineural Sinus- Ventral The Two diaphragms. a. Dorsal diaphragm- between Pericardial & Perivisceral sinuses b. Ventral diaphragm- between Perivisceral & Perineural sinuses University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 1. Sinuses and diaphragms. Dorsal Pericardial Sinus - It is separated by dorsal diaphragm from the middle perivisceral sinus. - It contains dorsal blood vessel. Middle Perivisceral Sinus - It is present in between dorsal and vental diaphragms and is largest sinus. - It contains alimentary canal (gut). Ventral Perineural Sinus - It is separated by ventral diaphragm from the middle perivisceral sinus. - It contains ventral nerve cord. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 1. Sinuses and diaphragms. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  1. Sinuses and diaphragms. Dorsal diaphragm  It is a septum: extends across the abdominal cavity enclosing the pericardial sinus , it contain the dorsal vessel.  The dorsal diaphragm divides the haemocoel into the pericardial sinus and the visceral sinus. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  1. Sinuses and diaphragms. Ventral diaphragm  The ventral diaphragm forms a continuous ventral sheath.  It extends from the prothorax to the end of the body.  It encloses the perineural sinus.  The perineural sinus encloses the nerve cord. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 2. Dorsal blood vessel  It runs along the dorsal midline , for the whole of the body, just below the terga.  It may be bound to the dorsal wall of the gut in head region above the esophagus.  It is divided into a posterior heart in which the wall is perforated and an anterior aorta which is a simple unperforated tube.  It collects blood from the abdominal cavity and discharges it in the head.  It is open anteriorly but closed posteriorly. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 2. Dorsal blood vessel Aorta:  It is simple, straight, unperforated tube (without any ostia or valves).  It opens anteriorly into cephalic cavity. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 2. Dorsal blood vessel Heart  It is perforated tube with openings called ostia.  The heart may be directly bound to the dorsal wall or suspended from it by elastic filaments.  It is restricted to the abdomen, but in cockroaches it is extended up to prothorax.  It is divided into a series of chambers which are separated from each other by distinct constrictions.  The number of chambers varies among different groups of insects  Pair of alary muscles are attached laterally to the walls of each chamber (Alary muscles ) University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 2. Dorsal blood vessel Aorta dorsal vessel Heart University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 3. Accessory pulsatile organs. In addition to the dorsal vessel, insects have other pulsating structures that maintain circulation through the appendages. These are muscular membranous structures, varying in shape and are situated at the base of the appendages, such as: Antennae Legs Wings University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Organs of Circulatory system 3. Accessory pulsatile organs. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Heartbeat Systole  It is the contraction phase of the heartbeat.  It results from the contraction of the muscles in the heart wall which starts posteriorly and spreads forward as a Wave. Diastole  It is the relaxation phase of the heartbeat.  It results from relaxation of the muscles assisted by the elastic filaments supporting the heart.  After diastole there is a third phase in the heart cycle known as diastasis in which the heart remains in the expanded stat. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Circulation Normal circulation At systole  The blood is pumped forwards through the heart, entering the perivisceral sinus through the anterior opening of the aorta in the head and through the excurrent ostia where these exist.  The valves on the incurrent ostia prevent the escape of blood through these openings.  The force of blood leaving the aorta anteriorly tends to push blood backwards in the perivisceral sinus.  The backwards flow is aided by the movements of the dorsal diaphragm and by the inflow of blood into the heart, through the incurrent ostia, at diastole.  Movements of the ventral diaphragm presumably help to maintain the supply of blood to the ventral nerve cord University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Circulation Normal circulation At diastole  Blood is drawn into the heart through the ostia. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Factors affecting the rate of the heartbeat  Age and stage Heartbeat is faster in adult than immature stages.  Environmental factors such as temperature.  Strong movement of the gut  It is also common for the heartbeat to undergo periodic reversal, with waves of contraction starting at the front. When this occurs, blood is forced out of the incurrent ostia University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Hemolymph  It consists of a fluid plasma in which blood cells, hemocytes, are suspended.  Making up usually less than 25% of an insect’s body weight.  Hemolymph water comprises 20-25% of the total body water in adult insects, but in caterpillars, the figure is close to 50%.  It transports hormones, nutrients and wastes and has a role in, osmoregulation, temperature control, Immunity, storage (water, carbohydrates and fats) and skeletal function.  It also plays an essential part in the moulting process.  An additional role of the hemolymph in some orders, can be that of predatory defence. It can contain unpalatable and odorous chemicals that will act as a deterrent to predators. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Hemolymph Insect Blood Cells (Hemocytes):  Several different types of blood cells occur.  Functions of hemocytes 1. Some hemocytes are phagocytic and function to eliminate microbial pathogens and tissues debris generated during embryonic development. 2. Some hemocytes protect against large foreign bodies by encapsulation. 3. hemocytes play a critical role in both development and immunity. The cell's derived material is required for normal development of ventral nerve cord and Malpighian tubules University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Hemolymph Functions of Plasma  Nutritive materials are carried out from alimentary canal and storage tissues to the sites at which they are metabolized.  Carrying excretory products from the place of origin to the malpighian tubules  Transporting hormones from endocrine organs to the site of action.  Store for some substances e.g., Trehalose as a source of energy and its supply is achieved rapidly from fat body  Water storage University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Hemolymph Functions of Plasma  Nutritive materials are carried out from alimentary canal and storage tissues to the sites at which they are metabolized.  Carrying excretory products from the place of origin to the malpighian tubules  Transporting hormones from endocrine organs to the site of action.  Store for some substances e.g., Trehalose as a source of energy and its supply is achieved rapidly from fat body  Water storage University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  University of Tabuk Faculty of science Department of Biology General Entomology (BIO1302) Chapter 8-Part 1 Academic Year 1446 First semester 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Outline (Excretory system) Malpighian tubules-rectum Other excretory structures Nitrogenous excretion Physiology of nitrogenous excretion Storage excretion Salt & water balance 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Excretory system 1-Malpighian tubules-rectum The Malpighian tubules & rectum, functioning as a unit, form the major excretory System in most insects. The blindly ending tubules, which usually lie freely in the hemocoel, open into the alimentary canal at the junction of the midgut and hindgut. Typically, they enter the gut individually but may fuse first to form a common sac or Ureter that leads into gut. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Excretory system Malpighian tubules of insects. https://shorturl.at/HOC9Y 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Excretory system 2-Other excretory structures Even in insects that use the rectum as the primary site of osmoregulation, The ileum may nonetheless be a site for water or iron resorption. In other species where the rectum is unimportant in osmoregulation, serving Only to store urine & feces prior to expulsion, the ileum often takes on this role. In few insects the labial glands may function as excretory organs. In apterygotes that lack Malpighian tubules the gland can accumulate and eliminate dyes such as ammonia carmine & indigo carmine from the hemolymph. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Schematic diagram of a generalized excretory system showing the path of elimination of wastes. https://shorturl.at/qSj6T University of Tabuk , Faculty of science, Department of Biology- Academic Year 23/04/1446 1446– 1st semester-First version  Excretory system 3-Nitogenous excretion 3.1-Nature nitrogenous wastes In nitrogenous waste structural complexity, toxicity and solubility go hand in hand. The simplest form of waste (ammonia) Is highly toxic and very water-soluble. It contains a high proportion of hydrogen that can be used in production of water. It is generally found as the major excretory product, therefore, only in those insects that have available large amounts of water such as larvae & adults of freshwater insects. Most insects, excrete their waste nitrogen as uric acid. This is only slight water-soluble, relatively non-toxic and contains a smaller proportion of hydrogen compared to ammonia. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Excretory system Excretion in Insects (Malpighian Tubules) https://shorturl.at/VzDK2 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Excretory system 3.2. Physiology of nitrogenous excretion Uric acid is produced in the fat body and/ or Malpighian tubules (occasionally the midgut) and released into hemolymph. The uric acid is secreted into the Lumen of the tubules as sodium or potassium salt, along with other ions, water and various low-molecular-weight organic molecules. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Excretory system 3.3.Storage excretion An alternative strategy to the removal of wastes though the Malpighian tubules-rectum system used by some insects is storage excretion, the retention Of the wastes in “out of the way place” within the body. For example, In dysdercus, uric acid is deposited permanently in the epidermal cells of the abdomen, forming distinct, white transvers bands. 23/04/1446 Dysdercus cingulatus University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester- First version Excretory system 4-Salt & water balance The major source of water for most terrestrial insects is obviously food and drink. In terrestrial insects, water is lost (1)by evaporation across the integument, although This is considerably reduced by presence of wax layer in the epicuticle. (2) During respiration through the spiracles. On Rhodnius & Dixippus insects' rectum is capable of resorbing salts. Rhodnius prolixus female of Dixippus insularis University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First 23/04/1446 version  Excretory system 4-Salt & water balance In freshwater insect's water enters the body osmotically despite the relatively impermeable cuticle and must be removed, and salts will be lost from the body and must be replaced if the hyperosmotic condition of the hemolymph is to be maintained. Freshwater insects can regulate their hemolymph osmotic pressure successfully to the point at which the external environment becomes Isosmotic with the hemolymph. This achieved by the production of urine That is hypoosmotic to the hemolymph. Reference: Entomology book, by Cedric Gillott, third edition, 2005. Springer, Netherlands University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First 23/04/1446 version Outline (respiratory system) TRACHEAE & OXYGEN DIFFUSION SPIRACLES AQUATIC RESPIRATION 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects respiratory system TRACHEAE & OXYGEN DIFFUSION: ▪ Insects, in general, do not have an oxygen-carrying chemical in their blood so oxygen reaches cells by other means. ▪ Most insects have a waterproof cuticle but some insects live in moist areas and are sedentary. Their cuticle is permeable to water and they obtain sufficient oxygen by diffusion across their cuticle. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Internal anatomy of insects respiratory system However, most insects have a special respiratory system comprising a system of internal tubes, called trachea, which branch and rebranch. Very fine branches, tracheoles, penetrate individual cells. Air enters from the outside through a series of openings, spiracles. Typically there are 2 pair of spiracles laterally on the thorax and 8 pair laterally on the abdomen. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects respiratory system 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects respiratory system ▪ SPIRACLES ▪ Insects need to avoid water loss through their spiracles and to prevent contamination by dust etc. Structure of spiracle and tracheal opening. ▪ Spiracles are therefore usually equipped with opening and closing devices and filtering lobes or hairs in an atrium before the beginning of the trachae. ▪ Very active insects have internal air sacs, as extra reservoirs, as part of their tracheal system. They also may employ mechanical ventilation along the larger trachae. Bees and wasps may extend and telescope their abdomens to pump air along. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects respiratory system Spiracles under electronic microscope 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects respiratory system ▪ AQUATIC RESPIRATION ▪ Many aquatic insects must return periodically to the surface to breathe. ▪ Mosquito larvae have tubes connecting to the air at the water surface. There are hydrofuge hairs (water resistant) associated with the spiracles, to break the surface tension of the water and to keep water out when the insect is underwater. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Internal anatomy of insects respiratory system ▪ Mosquito larvae 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects respiratory system ▪ AQUATIC RESPIRATION ▪ Other insects, such as stone fly, dragonfly and mayfly nymphs have tracheal gills whereby oxygen diffuses from the water to fine, surface trachae. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects respiratory system ▪ AQUATIC RESPIRATION ▪ Water beetles take a bubble of air with them underwater. Their spiracles open into the bubble As the oxygen in the bubble is used up, the oxygen pressure in the bubble drops to that of the surrounding water so that more oxygen diffuses into the bubble from the water. In this way the bubble remains usable for a long time. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects respiratory system ▪ Water beetles 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Outline (Reproductive system) Male reproductive system Male reproductive system functions Female reproductive system Female reproductive system functions Mating behavior Ovulation 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Reproductive system Male reproductive system: The male reproductive system comprises a pair of testes where spermatazoa are stored, which are located in the 5th and 6th abdominal segments. The first part of the genital duct is a pair of vasa efferentia, which are narrow, thin–walled tubes, then a pair of seminal vesicles which come together to form a common ejaculatory duct, and a pair of accessory glands which open into the ejaculatory duct. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Internal anatomy of insects Reproductive system Testis Vas efferentia Accessory Seminal gland vesicle Ejaculatory duct The reproductive system of male mosquito. Photo by Dr.Rowida Baeshen (thesis work) 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Internal anatomy of insects Reproductive system ▪ Male reproductive system functions: ▪ Functions of male reproductive system include production, storage, and finally delivery to the female of sperm. In some species, the system produces substances transferred during copulation that regulate female receptivity and fecundity (Gillott,2005). 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Reproductive system ▪ Female reproductive system: ▪ The female reproductive system comprises a pair of ovaries that are located dorsally in the posterior abdominal segments. The first part of the genital ducts is a pair of oviducts which come together to form a common oviduct. The vagina is located at the end of the common oviduct. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Reproductive system ▪ Female reproductive system: ▪ There are two additional organs important for reproduction: the spermatheca and the accessory gland. The ducts from the spermatheca and accessory gland open into the common oviduct. The female accessory gland is larger during the ovarian cycle and reduced in size at oviposition. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Reproductive system Female & male reproductive system: 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Reproductive system ▪ Female reproductive system functions: ▪ Functions of the female reproductive system include production of eggs, reception and storage sperm, sometimes for a considerable period and coordination of events that lead to fertilization and oviposition. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Reproductive system ▪ Mating behavior: ▪ May be subdivided into four components. ▪ The components are: ▪ 1-location and recognition of mate ▪ 2-courtship ▪ 3-copulation ▪ 4-postcopulatory behavior. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Reproductive system Mating behavior: 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Reproductive system ▪ Ovulation: ▪ Ovulation, the movement of an egg from the ovary into the lateral oviduct, may or may not be well separated in time from the actual process of egg laying (oviposition). Ovulation is induced by a neurosecretory factor from the brain. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Internal anatomy of insects Reproductive system Oviposition ( egg laying) is extremely important phase in an insect life history. It carried out at the correct time and suitable location. The eggs when laid must be protected from desiccation and predation. Further, Because larvae are relatively immobile, it is necessary to lay eggs close to or even on/in the larva's food. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version 23/04/1446 Outline (Nervous system) ▪Nervous system ▪Central nervous system 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Nervous system ▪The nervous system consist of nerve cells (neurons) and glial cells. Each neuron comprises a cell body where a nucleus, many mitochondria, and other organelles are located, and a cytoplasmic extension, the axon, which usually much branched. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Nervous system ▪ Central nervous system In adult insect the central nervous system comprises the brain, subesophageal ganglion, and a varied number of ventral ganglia. 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version The central nervous system of various insects showing the diversity of arrangement of ganglia in the ventral nerve cord. Varying degrees of fusion of ganglia occur from the least to the most specialized: (a) three separate thoracic and eight abdominal ganglia, as in Dictyopterus (Coleoptera: Lycidae) and Pulex (Siphonaptera: Pulicidae); (b) three thoracic and six abdominal, as in Blatta (Blattodea: Blattidae) and Chironomus (Diptera: Chironomidae); (c) two thoracic and considerable abdominal fusion of ganglia, as in Crabro and Eucera (Hymenoptera: Crabronidae and Anthophoridae); (d) highly fused with one thoracic and no abdominal ganglia, as in Musca , Calliphora, and Lucilia ( Diptera: Muscidae and Calliphoridae); (e) extreme fusion with no separate suboesophageal ganglion, as in Hydrometra (Hemiptera: Hydrometridae) and Rhizotrogus (Scarabaeidae). http://www.entomologa.ru/outline/33.htm 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version Internal anatomy of insects Nervous system 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version  Internal anatomy of insects Nervous system Insect’s nervous system is constantly receiving stimuli of different kinds both from the external environment and from within its own body. The subsequent response of insect depends on the net assessment of these stimuli within the central nervous system 23/04/1446 University of Tabuk , Faculty of science, Department of Biology- Academic Year 1446– 1st semester-First version University of Tabuk Faculty of science Department of Biology General Entomology (BIO 1302) Chapter 8 Insect Physiology (Endocrine System). Academic Year 1446 First semester  Outline ▪Hormones definition ▪The 2 types of the endocrine glands of insects ▪Role of other hormones in metamorphosis ▪Hormonal control of reproduction University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Endocrine system ▪ An insect's sensory, motor and physiological processes (including growth, reproduction, and protein formation) are controlled by the central nervous system along with the endocrine system. ▪ Endocrine system complement the nerve system , which provide short term coordination, and the activities of the two systems are closely linked University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Endocrine system ▪ The endocrine organs produce hormones which travel, usually in the blood, to various organs of the body, coordinating their activity. ▪ Hormones are chemicals produced within an organism's body and transported, generally in body fluids, away from their point of synthesis to sites where they influence a remarkable variety of physiological processes, even though present in extremely small quantities. ‫ﻧﻈﺎم اﻟﻐﺪد اﻟﺼﻤﺎء‬.‫ وﺗﻨﺴﻖ ﻧﺸﺎﻃﻬﺎ‬،‫ إﻟﻰ أﻋﻀﺎء ﻣﺨﺘﻠﻔﺔ ﻣﻦ اﳉﺴﻢ‬،‫ ﻋﺎدة ﰲ اﻟﺪم‬،‫ﺗﻨﺘﺞ أﻋﻀﺎء اﻟﻐﺪد اﻟﺼﻤﺎء ﻫﺮﻣﻮﻧﺎت ﺗﻨﺘﻘﻞ‬ : ‫اﻟﻬﺮﻣﻮﻧﺎت‬ ‫ ﺑﻌﻴﺪا ﻋﻦ ﻧﻘﻄﺔ ﺗﺨﻠﻴﻘﻬﺎ إﻟﻰ اﳌﻮاﻗﻊ اﻟﺘﻲ ﺗﺆﺛﺮ ﻓﻴﻬﺎ‬،‫ ﺑﺸﻜﻞ ﻋﺎم ﰲ ﺳﻮاﺋﻞ اﳉﺴﻢ‬،‫ﻫﻲ ﻣﻮاد ﻛﻴﻤﻴﺎﺋﻴﺔ ﺗﻨﺘﺞ داﺧﻞ ﺟﺴﻢ اﻟﻜﺎﺋﻦ اﳊﻲ وﺗﻨﻘﻞ‬.‫ ﻋﻠﻰ اﻟﺮﻏﻢ ﻣﻦ وﺟﻮدﻫﺎ ﺑﻜﻤﻴﺎت ﺻﻐﻴﺮة ﻟﻠﻐﺎﻳﺔ‬،‫ﻋﻠﻰ ﻣﺠﻤﻮﻋﺔ ﻣﺘﻨﻮﻋﺔ ﻣﻠﺤﻮﻇﺔ ﻣﻦ اﻟﻌﻤﻠﻴﺎت اﻟﻔﺴﻴﻮﻟﻮﺟﻴﺔ‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Endocrine system The endocrine glands of insects are of 2 types: 1. Neurosecretory cells within the central nervous system 2. Specialized endocrine glands such as i. Corpora cardiaca ii. Corpora allata iii. Prothoracic glands. iv. Weismann's ring/ Ring gland University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Endocrine system The main centres in a generalized insect University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Neurosecretory Cells ▪ Neurosecretory cells occur in all the ganglia of the central nervous system but are particularly abundant in the brain. ▪ Produce one or more hormones that affect growth, reproduction, homeostasis and metamorphosis. ‫أﻳﺶ اﻟﻐﺪة؟‬ ‫وﻳﻦ ﻣﻮﻗﻌﻬﺎ؟‬ ‫وش ﺗﻔﺮز؟‬ ‫ووش وﻇﻴﻔﺘﻬﺎ ؟‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Neurosecretory Cells ▪ Produce "brain hormone." Brain hormone is also called neurosecretory substance. ▪ This hormone, once synthesized in the brain, moves along nerve cells to an endocrine gland called the corpus cardiacum, where it is stored. Produce Neurosecretory Cells Brain hormone Store Corpora cardiaca University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  PTTH prothoracicotropic hormone (brain hormone) The main centres in a generalized insect University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Corpora cardiaca Corpora Cardiaca: are a pair of neuroglandular bodies that are found behind the brain and on either sides of the aorta. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Corpora cardiaca These not only produce their own neurohormones but they store and release other neurohormones including PTTH prothoracicotropic hormone (brain hormone), which stimulates the secretory activity of the prothoracic glands, playing an integral role in moulting. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Corpora cardiaca At certain times in the insect's development, the brain hormone is released from the corpora cardiaca into the hemolymph. Once in the hemolymph, the brain hormone is carried to a special target organ, the prothoracic gland, so called because it normally is located in the prothoracic region of the insect. Store and Release Corpora cardiaca Brain hormone Stimulate prothoracic glands University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  PTTH prothoracicotropic hormone (brain hormone) PTTH (Storage) The main centres in a generalized insect University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Prothoracic glands Prothoracic glands are diffuse, paired glands located at the back of the head or in the thorax. ‫ ارﺟﻊ ﻟﻠﺘﺴﺠﻴﻞ‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Prothoracic glands ▪ The prothoracic gland is stimulated by the brain hormone to produce another hormone called molting hormone, also known as ecdysone, which initiates the epidermal moulting process. Stimulated by prothoracic gland Brain hormone Produce ‫ ارﺟﻊ ﻟﻠﺘﺴﺠﻴﻞ‬ Molting hormone University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Prothoracic glands In most insects, these glands break down soon after the final molt to adult (exceptions: Thysanura which continue to molt after become adults, and some grasshoppers). Break soon after Prothoracic gland Final molt to adult ‫ ارﺟﻊ ﻟﻠﺘﺴﺠﻴﻞ‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  PTTH prothoracicotropic hormone (brain hormone) PTTH (Storage) Ecdysone (ecdysteroids) ‫ ارﺟﻊ ﻟﻠﺘﺴﺠﻴﻞ‬ The main centres in a generalized insect University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Prothoracic glands ‫ ارﺟﻊ ﻟﻠﺘﺴﺠﻴﻞ‬ Ecdysone is then transported by the hemolymph to specialized cells in the epidermis known as molting fluid cells. These cells are stimulated by ecdysone to produce the molting fluid. Molting fluid contains enzymes which digest away a portion of the old cuticle and aid the insect in the molting process. A new cuticle is then secreted by the epidermal cells. Prior to its completion, the insect will split the old exoskeleton at weak points called ecdysial sutures, which are located in the head and thoracic areas. ‫ﻗﺮﺗﻬﺎ اﻟﺪﻛﺘﻮرة ﻋﻠﻰ اﻟﺴﺮﻳﻊ‬ ‫ﻗﺎﻟﺖ ﻛﻼم ﻣﻌﺎد‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Prothoracic glands The splitting of the exoskeleton may be accomplished by taking in air and then muscle contraction which produces pressure along the ecdysial sutures. The insect will then crawl out of the old exoskeleton, and, by taking in air, stretch the new exoskeleton to a larger size before hardening of the new cuticle takes place. ‫ ارﺟﻊ ﻟﻠﺘﺴﺠﻴﻞ‬ University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Corpora allata ▪ Corpora allata are small, paired glandular bodies originating from the epithelium located on either side of the foregut (Oesophages). University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Corpora allata ▪ The hormones secreted by the corpora allata are referred to as juvenile hormones or "JH." As the name implies, these hormones maintain juvenile and immature characters within the developing insect University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  PTTH prothoracicotropic hormone (brain hormone) PTTH (Storage) JH Juvenile hormone Ecdysone (ecdysteroids) ‫ ارﺟﻊ ﻟﻠﺘﺴﺠﻴﻞ‬ The main centres in a generalized insect University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Through the interaction and the levels of juvenile hormone and ecdysone, insect growth and metamorphosis is regulated. ▪ When these hormones are present in sufficient quantity in the body, growth and molting occur, but juvenile hormone tends to keep the insect in immature stages by affecting genes which express the larval characters. ▪ In a later instar, juvenile hormone levels decrease, and adult tissues differentiate under the influence of ecdysone, and their levels, insect growth and metamorphosis is accomplished. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Weismann's ring/ Ring gland ‫ ارﺟﻊ ﻟﻠﺘﺴﺠﻴﻞ‬ ▪ Present in Cyclorrophous Diptera ▪ Formed by the fusion of Carpora cardiaca, Carpora allata, Prothoracic glands and Hypocerebral ganglion ▪ Occur as small ring like tissue supported by trachea around aorta ▪ Secrete puparium hardening hormone ▪ Controls metamorphosis in flies University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Role of other hormones in metamorphosis 1- Bursicon: Neurosecretory Cells in brain secretes bursicon which is involved in hardening and darkening of cuticle. Bursicon: Neurosecretory hormone that controls Tanning or Sclerotization and mechanical properties of the cuticle during and after a molt Sclerotization in fly pupae University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Role of other hormones in metamorphosis 2- Eclosion hormone: Neurosecretory cells of the brain produce eclosion hormone, which collects in the corpora cardiaca and is released into the blood at the time of switchover from pupal to adult stage University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Hormonal control of reproduction ▪ Like other higher multicellular organisms, reproduction in insects is a complex process. ▪ Different stages of reproduction, starting from the production of male and female gametes to oviposition, are seem to be influenced by several hormones. 1. Spermatogenesis 2. Vitellogenesis 3. Oogenesis 4. Fertilization University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Hormonal control of reproduction 1. Spermatogenesis: Regulated by ecdysone and juvenile hormone ▪ Ecdysone controls the permeability of the testis walls to the humoral factor differentiating the spermatocytes. ▪ Juvenile hormone is shown to have some inhibitory effects on spermatogenesis in many insects. 2. Vitellogenesis: Vetellogenesis or egg yolk synthesis is also known to depend on juvenile hormone from the corpora allata. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Hormonal control of reproduction 3. Oogenesis: Hormones from corpora allata help in egg maturation through the incorporation of yolk into the oocyte. 4. Fertilization ▪ In many insects studied, ovulation (the passage of egg from the ovary into the oviduct) and oviposition, (passage of fertilized eggs to the outside, are closely linked. ▪ Both these events are affected by some peptides secreted by male accessory glands and neurosecretory products of brain. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester University of Tabuk Faculty of science Department of Biology General Entomology (BIO 1302) Chapter 9 Insect Behavior (Elements of Behavior) Academic Year 1446 First semester  Outline What is Insect Behavior? Types of Insects Behavior Importance to Study Insect Behaviour Insect Communication University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  What is Insect Behavior?  An insect behavior refers to the various actions of an insect in response to a stimulus or to its environment. Hoy, M. A. (2019). Molecular Genetics of Insect Behavior. Insect Molecular Genetics, 413–461. https://doi.org/10.1016/b978-0-12-815230-0.00011-x University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Types of Insects Behaviour Insects mainly exhibit two kinds of behavior: (1) Innate behavior and (2) Learned behavior 1- Innate behavior: is behavior that's genetically hardwired in an organism and can be performed in response to a cue without prior experience. In general, innate behaviors will always be:  Heritable: encoded in DNA and passed from generation to generation.  Intrinsic: present in animals raised in isolation from others.  Stereotypic: performed in the same way each time by each individual.  Inflexible: not modified by development or experience.  Consummate: fully developed or expressed at first performance. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Types of Insects Behaviour 1-Innate behavior Example of innate insect behavior called the “dorsal light reaction”. Flying insects will sense the direction of light coming from the sun and fly in a way that keeps the sun overhead, or on their dorsal side. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Types of Insects Behaviour 2- learned behavior: Learned behavior is behavior that occurs only after experience or practice.  Learned behavior has an advantage over innate behavior. It is more flexible. Learned behavior can be changed if conditions change.  In insects, this learned behavior is exemplified by insects foraging for food. Honeybees, for instance, can learn from environmental signals to locate the food source. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester  Importance to Study Insect Behaviour 1. To understand interspecific and intraspecific interaction between insects. 2. To know the reproductive strategies of different insects. 3. To understand the social behaviour of insects. 4. To determine the host preference by different insects. 5. To understand the defensive mechanism of insects against their natural enemies. 6. Insects can resist insecticides through changing their behaviour. So, understanding the behavioural resistance mechanism will help in development of IRM strategies. University of Tabuk , Faculty of science, Department of Biology- Academic Year 1444 - 3rd Trimester   Insect behavior covers a wide range of activities, such as:  Feeding,  Locomotion,  Grooming,  Reproduction,  Learning,  Migration,  Communication. Un