Intra-puparial development of Lucilia eximia (Diptera, Calliphoridae)

Abstract

There are few studies about the intra-puparial development in Diptera, nonetheless its importance has been increased because several dipteran species are of forensic interest. Studies on the life cycles of flies often disregard the changes that occur inside the pupae. The objectives of this research were to analyze the intra-puparial development of Lucilia eximia, and to describe chronological and morphological changes that occur during this stage. Around 1.600 specimens were laboratory-reared. The pre-pupae were identified by the reduction of their size and change in coloration, and 10 individuals were sampled every three hours (n=1.000) until adult emergence. The specimens were fixed in 96% alcohol, subsequently immersed in Canoy solution for 24 hours and in formic acid (5%) for 48 hours, to facilitate dissection and analysis of the morphological changes of the individuals. Four stages of the intra-pupal development of L. eximia were observed: 1) Larva-pupa apolysis, which lasted 23 ± 1.08 h; 2) Cryptocephalic pupa, 5 ± 0.53 h; 3) Phanerocephalic pupa, 92 ± 1.94 h; and 4) Pharate adult: Transparents eyes, 125 ± 2.15 h; Yellow eyes, 23 ± 0.89 h; Pink eyes, 14 ± 0.73 h; and Red eyes, 20 ± 0.60 h. The pharate adult is completely formed after 296 hours and the emergence of the adult occurred after 302 ± 3.81 h. In addition, there were included the stage of pre-pupa, pupariation and the beginning of the adult stage, Imago and adult emergence. Each stage is described and compared with those described for Chrysomya albiceps (Calliphoridae). KEYWORDS: Immature insects, Metamorphosis, Forensic entomology, Postmortem interval.Desenvolvimento Intra-pupal de Lucilia eximia (Diptera: Calliphoridae) RESUMO No mundo existem poucos estudos sobre o desenvolvimento intrapupal de Diptera. Comumente, os estudos dos ciclos de vida das espécies de moscas são feitos eliminando o desenvolvimento embrionário que é muito importante, principalmente nas espécies de interesse forense. O principal objetivo foi o de analisar o desenvolvimento intrapupal de Lucilia eximia, descrevendo as mudanças morfológicas que ocorrem durante o desenvolvimento intrapupal. Foram analisados cerca de 1.600 espécimes cultivados em laboratório. Foram analisadas as fases de pré-pupa, pupa, o início da fase adulta, a imago e a emergência. Pré-pupas foram identificadas de acordo com a redução no tamanho e na alteração da coloração. Dez espécimes foram coletados a cada três horas (n=1.000), sem interrupção, até a emergência dos adultos. As pupas foram fixadas em etanol a 96%. Em seguida foram imersas em solução Carnoy por 24 horas e ácido fórmico a 5% por 48 horas para facilitar a dissecação e análises das alterações morfológicas. Foram determinados 4 estágios de desenvolvimento intrapupal. 1) Apólise larva-pupa com duração de 23 ± 1,08 h; 2) Pupa criptocefálica: 5 ± 0,53 h; 3) Pupa fanerocefálica: 92 ± 1,94 h e; 4) Adulto farado: olhos transparentes: 125 ± 2,15 h; olhos amarelos: 23 ± 0,89 h; olhos róseos: 14 ± 0,73 h e olhos vermelhos 20 ± 0,60 h. O a...

Post-Mortem Interval Estimation Based on Insect Evidence: Current Challenges

“…The most promising techniques for aging such evidence consist of the qualitative morphological analyses of the intra-puparial forms of the flies [ 30 , 35 , 36 ]. Intra-puparial development has been documented for many forensically important species [ 35 , 65 , 78 , 170 , 171 , 172 , 173 , 174 , 175 ]. Although these techniques have obvious advantages (e.g., they cover most of the intra-puparial development, they are generally non-destructive, low-cost and they need a stereomicroscope only), they have also important disadvantages (e.g., they are qualitative in nature and therefore less accurate and they are also impractical due to the need to have an expert knowledge in the intra-puparial morphology) [ 82 ].…”

From Laboratory Studies to Court Evidence: Challenges in Forensic Entomology

“…The most promising techniques for aging such evidence consist of the qualitative morphological analyses of the intra-puparial forms of the flies [30,35,36]. Intra-puparial development has been documented for many forensically important species [35,65,78,[170][171][172][173][174][175]. Although these techniques have obvious advantages (e.g., they cover most of the intra-puparial development, they are generally non-destructive, low-cost and they need a stereomicroscope only), they have also important disadvantages (e.g., they are qualitative in nature and therefore less accurate and they are also impractical due to the need to have an expert knowledge in the intra-puparial morphology) [82].…”

Intra‐puparial development in the hoverflies Eristalinus aeneus and Eristalis tenax (Diptera: Syrphidae)

“…Studies on dipteran intra‐puparial development have predominantly focused on species of applied interest, for example, to determine the post‐mortem interval in forensic cases (e.g., Brown, Thorne, & Harvey, 2015), or to improve strategies of biological control against pests (e.g., Cepeda‐Palacios & Scholl, 2000). For this reason, most of the Diptera that have been studied are necrophagous such as Calliphoridae (Ramos‐Pastrana, Londono, & Wolff, 2017; Salazar‐Souza, Couri, & Aguiar, 2018), Sarcophagidae (Kanti‐Sinha & Mahato, 2016) or Stratiomyidae (Barros‐Cordeiro, Báo, & Pujol‐Luz, 2014; Li, Wang, & Wang, 2016), among others (see Denlinger & Žďárek, 1994).…”