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  • ThesisItemOpen Access
    Effect of certain biopesticides and irradiation on the developmental stages of myiasis producing flies
    (Department of Parasitology, College of Veterinary and Animal Sciences,Mannuthy, 1998) Subramanian, H; KAU; Rajamohanan, K
    A study was undertaken on the prevalence of cutaneous myiasis in domestic animals and its control using bio-pesticides and gamma irradiation. The prevalence of cutaneous myiasis in domestic animals was found to be 205 (2.08 per cent) among .the 9861 animals screened. The peak of infestation was noted in the month of January. In host-wise and parasite-wise the highest incidence was noted in cattle (63.41 per cent) and the majority of infestation was produced by Chrysomya bezziana larvae (90.73 per cent). Methoprene at 1 to 50 ppm concentration caused only moderate mortality on larvae but significantly increased the mortality rate on eggs, prolonged the larval phase, increased the formation of larval pupal intermediaries and adult deformities and reduced the adult emergence. Diflubenzuron at 0.5 to 5 ppm caused 55 to 100 per cent larvicidal effect due to lowered chitin content of 18.42 to 52.11 per cent in larval cuticle. Bacillus thuringiensis var israelensis produced only moderate larval mortality at 160 to 800 ppm in myiasis producing flies. Azadirachtin at 10.5 to 15 ppm produced 100 per cent mortality in eggs and larvae. Significant antifeedant, ovipositional deterrent and repellant effects were also produced by Azadirachtin. Among the extracts of Acarus calamus, studied, petroleum ether extract at 2.5 per cent concentration gave 82.5 to 100 per cent mortality of the larvae. Moderate antifeedant, ovipositional deterrent and repellant effects were also noticed. The petroleum ether extract produced 100 per cent sterility at 0.1 to 1 per cent concentration by preventing the development of ovarian follicles. Three day old pupae of myiasis producing flies exposed to r-rays gave excellent sterility effect at 2000 to 4000 rads radiation exposure without any other deleterious effect in the flies. Diflubenzuron at 5 ppm concentration showed the highest larvicidal effect (88.5 per cent) in natural cases of cutaneous myiasis.
  • ThesisItemOpen Access
    Studies on the flies producing cutaneous myiasis in domestic animals in Trichur
    (Department of Parasitology, College of Veterinary and Animal Sciences, 1978) Subramanian, H; KAU; Raja Mohanan, K
    A detailed study on the incidence of cutaneous myiasis among domestic animals in Trichur, the morphology and biology of the causative flies and the efficacy of indigenous oils and chemicals as repellents against these flies were undertaken. Cutaneous myiasis was found common among domestic animals in Trichur during the months of October to May, the maximum number being, during January to March. The cases were observed in cattle, buffaloes, goats and dogs. The most common causative fly was Chrysomyia bezziana, but other flies such as Chrysomyia megacephala, Chrysomyia rufifacies and Lucilia cuprina were also observed. In cattle and buffaloes, the lesions were noted mostly in vulval lips and nasal septa where as in goats and dogs the cases were observed on the body skin. The flies of Chrysomyia megacephala, Chrysomyia rufifacies, Chrysomyia nigripes, Lucilia cuprina and Sarcophaga ruficornis were reared in the laboratory to study their morphology and biology. The larvae of Lucilia cuprina and Sarcophaga ruficornis were smooth. Chrysomyia bezziana, Chrysomyia megacephala and Chrysomyia nigripes were spiny and Chrysomyia rufifacies hairy. Chrysomyia rufifacies had the shortest life cycle period of 16 days and Sarcophaga ruficornis had the longest of 26 days. Lucilia cuprina could be reared in the laboratory for 71 days. The invitro development of the larvae, the development of the pupae and the process of fly emergence of Chrysomyia megacephala and Sarcophaga ruficornis were studied in detail. Among the fly repellents tested, lemongrass oil proved to be the best one in possessing fly repellent potentially followed by camphor in oil and Eucalyptus oil against blowflies and Sarcophaga species. Kerosine oil and Turpentine oil possessed the maximum larvicidal action on the larvae of Chrysomyia megacephala and Sarcophaga ruficornis. Turpentine oil and pine oil possessed excellent ovicidal action on Lucilia cuprina eggs even on smearing.