Biologia e ecologia química de besouros (Insecta: Coleoptera) de importância forense

Abstract

Forensic Entomology applies the study of insects to legal issues. The moment the insect arrives at the decomposing body, as well as its development time there, can indicate the circumstances of the death and help solve criminal cases. In this context, studies into the life cycle and food attractiveness of insects of forensic importance are essential. Among the Coleoptera with forensic importance, Oxelytrum discicolle (Brullé, 1840) (Coleoptera: Staphylinidae: Silphinae) and Deltochilum rubripenne (Coleoptera: Scarabaeidae: Scarabaeinae) are species with potential for bioindication in criminal investigations. This study aimed to: (1) measure the duration of each larval and pupal stage of O. discicolle until the adult stage, differentiating between females and males; (2) measure the longevity of each individual of the species, differentiating between the sexes; (3) investigate the feeding attractiveness of males of O. discicolle and females and males of D. rubripenne for Sus scrofa bodies in the fresh and advanced stages of decomposition, colonized or not by arthropods. The life cycle of O. discicolle, under conditions of 25°C ± 2°C, relative humidity of 75% ± 10% and a 12-hour photoperiod, lasts 16.73 ± 1.56 days, with the L3 stage (8.83 ± 0.17 days) and the duration of the L1 - Adult cycle (17.38 ± 0.19 days) being longer for males. The longevity of females and males is 62.63 ± 18.0 days, with no significant difference between the sexes. With regard to the role of body volatiles in interactions with beetles, males of O. discicolle have a preference for odours from decomposing bodies in the later stages over those emitted by bodies in the early stages of decomposition, with no significant interference in the choice of arthropod colonization. Females and males of the species D. rubripenne are attracted to the early stages of decomposing bodies, and the previous colonization of arthropods does not significantly interfere with this choice. Thus, this work concludes that the volatiles released by decomposing bodies must modulate the colonization of these species in corpses, and may have important implications for forensic cases.