Larvae and adult flies of Rhinoestrus purpureus and R. usbekistanicus: morphology and pupation (Diptera: Oestridae).

Abstract

Rhinoestrus species larvae are considered obligatory parasites of the nasal cavities of equine. This type of myiasis is characterised by sneezing, coughing, olfactory nerve damage and encephalomyelitis. Also, it has a zoonotic importance as the larvae might cause ophthalmomyiasis and conjunctivitis in human. While few studies describing R. purpureus adult fly antennal sensillae are available, the R. usbekistanicus antennal sensillae have never been described. Also, scanty data are available on the adult flies of Rhinoestrus species morphology. For this reason, the current study aimed at identiying and comparing different Rhinoestrus species (larvae, adult flies and time of pupation). Using light and scanning electron microscopy, we have evidenced differences between R. purpureus, R. usbekistanicus larvae in spination pattern, shape of spines, peritremes shape and ultrastrucures. The study also showed that for both species the pupa required 15‑21 days at room temperature to develop into adult flies, identified the adult male flies and female external genitalia have been identified. As well, the gross features of R. purpureus and R. usbekistanicus adult flies which included the disposition of the parafrontalia and parafascialia tubercles, mesonotal weals, wings and abdominal pellonisityhave been characterised and the sensillae compared.