Adhesive attachments of the endangered botfly, Portschinskia magnifica (Diptera: Oestridae)

Portschinskia magnifica (Diptera: Oestridae) is an endangered subcutaneous parasitic fly that is mainly distributed in Eurasia. The external morphology of the main adhesive attachments that include the pretarsus and tarsus is studied using scanning electron microscopy. Two types of tenent setae that are characterised as spoon-like tip and pointed-like tip, which can increase the contact points for attachment to a surface, are described in this study. Hairs around the bristle of the empodium in P. magnifica are much denser than those of other flies, and thus, we proposed that the dense hairs around the empodium may be a more efficient way to perform the sensory function. Compared with saprophagous flies that are reported previously, the microsculpture of the unguitractor plate is obviously different in that microplates are scale-like and similar to those of the water bug, Ranatra linearis. In addition, microtrichia found in the lateral region of the unguitractor plate provides stronger fixation between two surfaces. These results provide anatomical information that allows us to understand the role of the pretarsus as an attachment device.