Botfly

Abstract: The impact of botfly (Cuterebra grisea) parasitism on populations of Microtus townsendii was studied on four areas near Vancouver, British Columbia, from 1971 to 1978. Botfly larvae were found in voles during the period from late June to late November, with a peak occurring from mid-August to mid-September. There was a significant negative relationship between vole density and the proportion of the population infested. The percentage of voles infested changed in the following manner in the three weight classes: juveniles (18.5%) > adults (16.5%) > subadults (13.0%), with the sexes showing no differences between them. Overall, noninfested voles always survived better than infested ones did in the three classes. In both adults and juveniles, survival declined as botfly larvae number increased; subadults did not show this relationship. Infested adult male voles survived more poorly at high densities (r = 0.62); adult females did not. Infested large adult males (≥ 55 g) survived better than small adults did (...

Abstract: “Myiasis-causing flies” is a generic term that includes species from numerous dipteran families, mainly Calliphoridae and Oestridae, of which blowflies, screwworm flies and botflies are among the most important. This group of flies is characterized by the ability of their larvae to develop in animal flesh. When the host is a live vertebrate, such parasitism by dipterous larvae is known as primary myiasis. Myiasis-causing flies can be classified as saprophagous (free-living species), facultative or obligate parasites. Many of these flies are of great medical and veterinary importance in Brazil because of their role as key livestock insect-pests and vectors of pathogens, in addition to being considered important legal evidence in forensic entomology. The characterization of myiasis-causing flies using molecular markers to study mtDNA (by RFLP) and nuclear DNA (by RAPD and microsatellite) has been used to identify the evolutionary mechanisms responsible for specific patterns of genetic variability. These approaches have been successfully used to analyze the population structures of the New World screwworm fly Cochliomyia hominivorax and the botfly Dermatobia hominis. In this review, various aspects of the organization, evolution and potential applications of the mitochondrial genome of myiasis-causing flies in Brazil, and the analysis of nuclear markers in genetic studies of populations, are discussed.

Abstract: Myiasis of different organs has been reported off and on from various regions in the world. We report a human case of external ophthalmomyiasis caused by the larvae of a sheep nasal botfly, Oestrus ovis, for the first time from Meerut city in Western Uttar Pradesh, India. A 25-year-old farmer presented with severe symptoms of conjunctivitis. The larvae, 3 in number, were observed in the bulbar conjunctiva, and following removal the symptoms of eye inflammation improved within a few hours.