A Study of the Pupal Development of Five Forensically Important Flies (Diptera: Brachycera)

Abstract

Holometabolous insects undergo complete metamorphosis, and hence, they have different phases of development (egg, larva, pupa, and adult), which occupy distinct ecological niches. The pupae of several fly species are surrounded by the puparium, which is a rigid structure, usually formed by the integument of the last larval instar. The puparium presents unique characteristics distinct from those of the larval and adult phases. During intrapuparial development, it is possible to distinguish at least four fundamental and continuous steps, namely: 1) larval–pupal apolysis, 2) cryptocephalic pupa, 3) phanerocephalic pupa, and 4) pharate adult. The objective of this work was to describe the external morphology of the distinct phase of development for five species that were collected, identified, and raised in the laboratory; intrapuparial development was studied by fixing immature specimens at regular intervals; the morphological analyses were performed with the aid of both light and scanning electron microscopy. Under the conditions established (27 ± 1.0 or 23 ± 1.0°C, 60 ± 10% relative humidity, 12 h of photoperiod), the minimum time for intrapuparial development was: 252 h for Megaselia scalaris (Loew 1966) (Phoridae), 192 h for Piophila casei (Linnaeus 1758) (Piophilidae), Fannia pusio (Wiedemann 1830) (Fanniidae), and Musca domestica (Linnaeus 1758) (Muscidae), and 96 h for Chrysomya megacephala (Fabricius 1794) (Calliphoridae). Intrapuparial development has defined steps, and distinct species responded differently to the same environmental conditions. In addition, it is possible to establish a sequential rule without ignoring the specific characteristics of each taxon.

Characterization of intrapuparial development of Musca domestica (Diptera: Muscidae), under different temperatures in laboratory conditions

“…Therefore, we argument on the existence of substantial intervenient factors responding for the differences on available literature findings, in confrontation of those of the present study. Barros-Cordeiro et al (2021), Fraenkel and Bhaskaran (1973), as well as the results of the present study provide parameters of great relevance for the literature, since the more specifically the data refers to a certain region, the more accurate the result will be for the calculation of the min PMI estimative.…”

“…Barros-Cordeiro et al (2021) conducted a pupal development study of M. domestica , under the temperature of 23 ± 1 °C, in the Midwest region of Brazil, where the morphoclimatic domain is of the cerrado biome. The methodology used was light microscopy and scanning electronic microscopy.…”

Complete Mitochondrial Genome of Piophila casei (Diptera: Piophilidae): Genome Description and Phylogenetic Implications

“…Until recent times, P. megastigmata was found to be more prevalent on cadavers than P. casei [ 12 ]. However, the genetic information available on P. casei is still limited, and forensic entomologists rely mostly on morphological observations rather than genetic comparisons to distinguish and compare the appearance of P. casei and P. megastigmata [ 13 , 14 ].…”

Age Determination of Chrysomya megacephala Pupae through Reflectance and Machine Learning Analysis

“…Nevertheless, these indicators are primarily suited for larval developmental time inference. The transition of necrophagous fly larvae into the pupa stage poses challenges in observing morphological temporal changes, making it difficult to determine their developmental time [ 14 , 15 ]. Therefore, there is a need to explore more suitable methods for inferring the pupa stage.…”