Morphological and scanning electron microscopic (SEM) studies of the pupae of Wohlfahrtia magnifica

Bactrian camel vaginal myiasis was caused by the larvae of Wohlfahrtia magnifica, and the development process of W. magnifica includes 3 metamorphic stages: larvae, pupae and flies. The morphological characteristics of the pupae stage of W. magnifica were observed by ultradepth imager and scanning electron microscopy (SEM). Through observation, the pupae eclosion process was divided into 3 stages, the 1st stage was from 1–4 days, its interior structure showing white and sticky; the 2nd stage was from 5–9 days, the head, wings, feet and abdomen of the pupa were forming and present milky white; the 3rd stage was from 10–12 days, the organs were developed and formed, and all coloured. Scanning electron microscopy (SEM) showed that the 1st, 2nd and 3rd segments of the head antennae were distinct in the 3rd stage of pupae, the 1st segment like a goat horn, the 2nd segment was trapezoidal, and the 3rd segment was rectangular with 2 aristate the outside. The antennae are covered with a large number of bristle, and the structure of bristle was flat and folded. Claw pads and claws were clearly observed on the feet, and there were a large number of bristle on its surface. The interval between the concave parts of the shell of W. magnifica pupae was uniform, but have not forming seven thoracic segments similar to that of the larval stage. The pupa shell was dark brown with evenly spaced segments and toughness, and not easily cut by sharp blades. Flies emerged from 13–15 days later. In this paper, we describe the morphological structure of pupae in its 3 development stages, which provided a biological data for the prevention and control of W. magnifica myiasis.