Ultrastructure of adult Gasterophilus intestinalis (Diptera: Gasterophilidae) and its puparium

Abstract

This research was conducted to identify the most common equine stomach bot fly by using light and scanning electron microscopy. Third instar larvae (n = 200) of Gasterophilus intestinalis were collected from stomach of slaughtered donkeys (Equus asinus) at Giza Zoo abattoir, Egypt, in July 2017 (the donkeys chosen were from Giza; Egypt). One hundred only were full mature 3rd instar larvae (the mature 3rd instar was active and has brown bands on its dorsal surface) which were incubated at 32 °C and 80–85% Relative Humidity (RH), for the development of adult. The following pupal parameters were recorded: prepupal period, number of pupated larvae, pupal period, and number of emerged adult and determination of adult sex ratio. Morphological description of pupae, puparium and adults were provided using light and scanning electron microscopy (SEM). The length of prepupal duration was five days and about 90% of the collected G. intestinalis larvae successfully pupated with pupal duration lasting for 21–25 days prior to emergence of the adult stage. Adults sorted according to sex show a female to male ratio of 8:1 (i.e. 80 females to 10 males). The pupae of G. intestinalis were brown to black in color. The adult head, thorax, abdomen, legs and wings of male and female were morphologically described using light and SEM. This research fully describes the adult G. intestinalis male; female and its puparium to distinguish it from other specific myiasis producing flies within its family.