Scanning electron microscopical study of third instar of gasterophilus haemorrohidalis [diptera: gasterophilidae]

ABSTRACT

Third-stage larva of the bot-fly Gasterophilus haemorrohidalis obtained from the stomach of Egyptian equines were studied macroscopically and by light microscope; and for the first time by the scanning electron microscope with particular reference to the anterior cephalic region and the newly discovered sensory array of the mouth hooks. The design of that array was compared with that of larvae of Gasterophilus intestinalis and Gasterophilus nasalis and was found to be different mainly in the shape of the sensilla and the number of the angled plates and that these fine criteria may be used to differentiate other larvae. In addition, more detailed description was added to the cephalic and caudal regions which are of important taxonomic value. Gasterophiline larvae are of veterinary and medical importance, with some human creeping cutaneous myiasis, ophthalmomyiasis and one recent record of intestinal myiasis