Reproductive and Sensory organs.pdf

REPRODUCTIVE SYSTEM  Sexual reproduction The female produces eggs that are fertilized by males The eggs are placed near the required food Female Reproductive System Ovary Function of the female reproductive system Mature eggs leave the ovaries through short l...

REPRODUCTIVE SYSTEM  Sexual reproduction The female produces eggs that are fertilized by males The eggs are placed near the required food Female Reproductive System Ovary Function of the female reproductive system Mature eggs leave the ovaries through short lateral oviducts. Near the midline of the body, these lateral oviducts join to form a common oviduct which opens into a genital chamber called the bursa copulatrix. Female accessory glands (one or more pairs) supply lubricants for the reproductive system and secrete a protein-rich egg shell (chorion) that surrounds the entire egg. These glands are usually connected by small ducts to the common oviduct Sperm are released from the spermatheca which is the storage for the sperm. The spermathecal glands provide nutrients for the sperm in the spermatheca. Then, the egg is fertilized and released through the ovipositor. Male Reproductive System follicle springer.com Function of the male reproductive system The male reproductive system is composed of a pair of testes, the vas deferens, seminal vesicle, ejaculatory duct and aedeagus. The follicle is the functional unit of the male reproductive organ. At the end of each follicle are the spermatogonia dividing through mitosis to form spermatocytes. Then, the spermatocytes will undergo meiosis to yield spermatids and develop into mature spermatozoa. The mature sperm will pass through the vas deferens then goes to the seminal vesicle for storage. Before the sperm goes out the accessory glands will produce seminal fluid to provide nourishment and spermatophore to encase the sperm and protect it before going to the ejaculatory duct and aedagus.  Insect Sensory Organs Department of Pest Management College of Agriculture and Food Science  Insect Sensory Organs Mechanoreceptor Chemoreceptor Photoreceptor Department of Pest Management College of Agriculture and Food Science  A common characteristic of all types of sensory neurons is that they transduce the stimulus energy, such as light, heat, chemical, or mechanical energy, into a slow, or graded, electrical potential. Department of Pest Management College of Agriculture and Food Science  Mechanoreceptors Insect mechanoreceptors can be found almost anywhere on the surface of an insect’s body Trichoid sensilla (literally hair-like little sense organs) They may act as tactile receptors, detecting movement of objects in the environment, or they may provide proprioceptive cues (sensory input about the position or orientation of Department of Pest Management the body and its appendages) College of Agriculture and Food Science  Mechanoreceptor A chordotonal sensillum is anatomically more complex than a tactile hair. It occurs at most exoskeletal joints, limb joints, and tympanum body segment joints. For sensing auditory stimuli or leg movement Example: Tympanum (insect ears) - Department of specialized for high-frequency sound detection Pest Management College of Agriculture and Food Science  Chemoreceptors 2 Types of chemoreceptors Gustatory receptors Important when chemicals are in solid or liquid form (usually at higher concentrations) most abundant on the mouthparts, but may also be found on the antennae, tarsi, and Department of Pest genitalia (especially near the tip of the female’s ovipositor) Management College of Agriculture and Food Science  Chemoreceptor Olfactory receptor Important when chemicals are present in gaseous form (at relatively low concentrations) Most abundant on the antennae but may also be associated with mouthparts or external genitalia Department of Pest Management College of Agriculture and Food Science  Photoreceptors Dioptric appratus Department of Pest Management Insect view of flower meadow. A wild flower meadow viewed through College of an insect's compound eye. The view from an insect's compound eye is Agriculture and Food Science not as sharply focused as that of a lens-eye (such as a human eye). However, the field of view is much wider: about 70 degrees compared to 5 degrees for human vision. (Sciencephoto.com)  Ocelli (Simple eyes) Two types of “simple eyes” can be found in the class Insecta: dorsal ocelli and lateral ocelli (=stemmata) Department of Pest Dorsal ocelli are commonly found in adults and Lateral ocelli (=stemmata)are the sole Management in the immature stages (nymphs) of many visual organs of holometabolous larvae College of Agriculture and hemimetabolous species. They appear as two or Food Science three small, convex swellings on the dorsal or facial regions of the head. Department of Pest Management College of Agriculture and Food Science