Animal Parasitology ANSC 164 PDF

 Species of this order are the sucking lice  They are wingless insects living as ectoparasites on mammals  Mouthparts are adapted for sucking the tissue fluids and blood  Two antennae are visible at the sides of the head with five segments  No sexual demorphism  Thorax is small and its...

 Species of this order are the sucking lice  They are wingless insects living as ectoparasites on mammals  Mouthparts are adapted for sucking the tissue fluids and blood  Two antennae are visible at the sides of the head with five segments  No sexual demorphism  Thorax is small and its three segments are fused  Abdomen relatively large, with seven of the nine segments visible  Paratergal plates- dark brown or black thickened chitin at the sides of abdomen  Eyes are reduced or absent  First pair of legs is usually smaller with weaker claws  Third pair of legs is usually the largest  Each tarsus has only one claw  Tibial pad- spiny pad which helped to hold in the hair  Head is usually more or less pointed anteriorly  Haematopinus asini- sucking louse of equines  H. bufali- sucking louse of buffalo in Africa  H. suis- large louse of pigs  H. eurysternus- ‘short-nosed’ cattle louse  Hog lice are small wingless, bloodsucking (hematophagous) insects that live on the surface of their hosts. They are obligate parasites, i.e., they cannot complete their life cycle off the host.  Adult females lay eggs (nits), which they glue one by one to single hairs of the host, close to the skin. The eggs hatch 5 to 20 days later.  Nymphs are bloodsucking as well, and they moult three times before reaching the adult stage in about 2 weeks.  The complete life cycle lasts about 30 days  Preferential sites of hog lice are the skin folds around the neck and the dewlap, in and around the ears, the legs and the flanks where they can congregate in large masses.  Cimex lectularius – bedbug  Attacks man and animals to suck blood  4-5 mm long, flat bodied, elongate oval in shape  Yellowish brown to dark brow in color  Head bears long antennae with four joints  Eyes projects at the side of the head  Wings are vestigial  Abdomen has eight visible segments  Whole body is covered with spinose bristles and some hairs  Tibiaare long and tarsi have three joints  Adults has a pair of ventral thoracic stink glands  Mouthparts are modified for piercing and sucking  Labrum is small and immovable  Female lays about 150-200 eggs in dark crevices  Larva hatches after 3-14 days at 23 degrees C or longer  There are five nymphal stages  Adult stage is reached in 8-13 weeks after hatching  Bugs can live long and survive of starvation  They are nocturnal insects but will bite in the daytime  After blood meal bugs defecates and turn around near the wound  Chlordane  Dieldrin  DDT  Organophosphates  Oil based sprays with pyrethrins  Fleas are wingless insects with laterally compressed bodies, 1.5-4 mm long  Chitinous covering is thick and brown  Compound eyes are absent, some species have large or small simple eyes  Abdomen has ten segments  Ninth abdominal segments bears a dorsal plate called sensilium or pygidium  Penis (aedeagus) is chitinous and coiled  Legs are long, strong and adapted for leaping  Combs or ctenidia- large spines on the head and the thorax  Ctenocephalides felis- cat, dog, man, mouse, rat and primates, cosmopolitan  Ctenocephalides canis- restricted to dogs and related species, cosmopolitan  Archaeopsylla erinacei- hedgehogs in Europe and N. America. Found also in dogs and cats  Spilopsyllus cuniculi- restricted in rabbit and hare  Leptopsylla segnis- occurs on the house mouse, rat, field mouse, wild rodents  Ceratophyllus fascialtus- common rat flea  Xenopsylla cheopis- oriental or black rat flea  Pulex irritans- human flea may occur on pig, dog, cat and rat  Tunga penetrans- man, pig and baboon  Ceratophyllus gallinae- common flea of chicken  Ceratophyllus columbae- domestic pigeon  Echidnophaga gallinacea- common chicken flea in tropical and subtropical area  Female flea lays up to 20 eggs at a time and some 400-500 during her lifetime  Oval, eggs are deposited in dust or dirt, laid on host soon drop off  0.5 mm long rounded at the poles and pearly white in color  Larvae may hatch in 2-16 days  Larvae are elongate, slender, maggot-like consisting 3-10 abdominal segments with long hairs  Last segment bears hooked processes called anal struts for holding and locomotion  Larvae are creamy yellow in color, very active hiding from light  With masticatory mouth parts feed on dry blood, feaces and other organic matter  They are found in crevices in floors, carpets, nest litter, sleeping places  Larval development 7-10 days or longer  Pupal stage last 10-17 days under average condition, may last several months  Fleas are mostly found in animals with poor condition, with debilitating disease and old animals.  Animals are restless, lose condition and spoil coats by biting and scratching.  At the site of infection, elevated levels of immunoglobulin E and Eosinophilia  Severe pruritic reactions at the lumbar-sacral area, abdomen, inside hindlegs and neck  Hyperpigmentation and hyperkeratinization  ‘Miliarydermatitis’, flea hypersensitivity in cats associated with small papules and pruritus.  Important also in transmission of diseases.  Bubonic plague (Yersinia pestis) carried by Xenopsylla cheopis  Tularemia (Francisella tularensis) transmitted by rat flea  Flea collar with dichlorvos  Coumaphos (Asuntol)  Corticosteriods to reduce pruritus  Premises should be clean with insectiside  Chlorinated Hydrocarbons  Diazinon or malathion