Ultrastructure of immature stages of the blowfly Chrysomya putoria (Wiedemann, 1818) (Diptera: Calliphoridae).

Forensic entomology is an area of science that serves as a tool in crime scene investigations. Usually, flies are the first insects to reach a carcass and can oviposit just a few hours after arrival. Therefore, the knowledge of immature stages is essential for correct identification of the species found on corpses. Scanning electron microscopy (SEM) gives detailed information about morphological characters helping to identify the immature forms of flies. Chrysomya putoria (Wiedemann) is a very important fly for forensic entomology, because it has high population densities and is easily found in colonizing carcasses, moreover, it is also a possible causative agent for secondary myiasis. The aim of this study is to identify larvae and puparia of C. putoria using SEM. The first instar larvae were composed of 12 smooth segments separated by spines. Antennae and maxillary palps were visible. Anterior spiracle was absent and only one spiracular opening could be seen at the posterior spiracle. Second and third larval instars were similar to first instar, except for the presence of anterior spiracle that is composed by 11-12 spiracular ramifications. At the anal segment, two spiracular openings were found in second instars and three openings in third instar larvae. Puparia showed a retracted cephalic region and none of the head structures were visible.