Scanning electron microscopic study of the antennal sensilla of female Sarcophaga orientaloides (Senior White, 1924), a flesh fly of forensic importance and its association with a filamentous fungus

Abstract

During the current study, scanning electron microscopic (SEM) analysis of the antennal sensilla and mechanoreceptors of a medically important flesh fly, Sarcophaga orientaloides collected from an urban habitat of West Bengal, India was done to delineate the role of diverse types of antennal sensilla involved in olfactory perception for the purpose of foraging, behavioral communication, locating oviposition sites and conspecific mates. The three segmented antenna of S. orientaloides was found to have a pair of cone shaped scape (Sc), a pair of pedicel (Pd) and a pair of long distally projected funiculus (Fn). A dorsoproximally directed long bushy arista (Ar) emerging out from the base of each funiculus was also observed. Different proportions of diverse types of sensilla including trichoid sensilla (Tr), basiconic sensilla (BaI), cheatic sensilla (ChI and ChII), companiform sensilla (Ca), sensory pits, sensory bristles, short clustered microtrichia and long bushy microtrichia (Mc) were observed all over the scape, the pedicel and the funiculus segments of antenna. Additionally, fungal spores measuring about 4–5 μm in diameter of a filamentous fungus was found to be embedded as clumps or situated solitary on all over the antennal segments except arista in female S. orientaloides specimens, which is the first report of the association of a forensic fly with a filamentous fungus and also demarcates the blockage/retardation of olfactory receptiveness which might cause difficulties in foraging and locating oviposition sites in S. orientaloides females. The association also outlines the future possibility of applications of forensic mycology in forensic entomology.