Aspects of the reproductive behaviour and development of two forensically relevant species, Blaesoxipha (Gigantotheca)stallengi (Lahille, 1907)and Sarcophaga (Liopygia)ruficornis (Fabricius, 1794)(Diptera: Sarcophagidae)

Abstract

We studied aspects of the reproductive behaviour and development of two species of Sarcophagidae (Diptera)of potential forensic importance, Blaesoxipha stallengi (Lahille, 1907)and Sarcophaga ruficornis (Fabricius, 1794), which are dominant in assemblages in dry forests in Northeastern Brazil. We described the behavioural acts associated with courtship and mating and estimated the development time (from egg/larva until adult)– of both species. Description of the reproductive behaviour was based on 50 couples of each species whereas 250 larvae were used for the estimation of the developmental time. A total of 55 successful copula were observed for B. stallengi and 142 for S. ruficornis. Pre-copulatory behaviour differed between the species, as S. ruficornis presented a high rate of competition among male specimens. Blaesoxipha stallengi copulated more frequently in the morning and the mean duration of copulation was similar for both species. The species showed different reproductive strategies: S. ruficornis follows the typical strategy in Sarcophagidae and are viviparous (larviparity), but we report here the first documented evidence of ovoviviparity of B. stallengi. Sex ratio of the emerged adults did not differ (p > 0.05)markedly for either species. Total development time in days was similar with 22.9 for B. stallengi and 21.3 for S. ruficornis. The pronounced similarities in the morphology of both species – combined with their similar time of development – may act as confounding factors for forensic entomologists and stress out the need for an accurate taxonomical identification.