Bionomy of Hermetia illucens (Diptera: Stratiomyidae) on Decomposing Swine Carcass in an Urban Area of Central Amazon.

Biological data on development of Hermetia illucens (Linnaeus, 1758) is useful to calculate the postmortem interval (PMI), thus being important for solving crimes. We aimed at gathering bionomic information on H. illucens, during the decomposition of a Sus scrofa, in the urban zone of Manaus, Amazonas State. Mature females and eggs were collected on the swine carcass. After hatching under natural conditions, larvae were observed daily. Different instars were fixed in ethylic alcohol to determine instar duration by the evaluation of the frequency distribution of cephalic capsule measurements and the principal components analysis (PCA). Females laid 620-700 eggs per posture in concealed locations preferentially, such as cranial cavities and slots on the metal cage. The larvae were found under the swine skin and on bones. After feeding, the larvae of H. illucens began to move slowly to pupate, did not seek for drier sites to do it, and buried themselves into the carcass instead. Pupae were observed as of the 60th day after death. H. illucens completed its life cycle in 53-82 d, which encompassed six larval instars and the pupa. About 93% of the eggs hatched, 11% reached the adult stage and the sex ratio was 0.49. Our results are complementary to the biological information of this species in Central Amazon, since most of the data were not known yet. This should render PMI calculation more accurate, even for corpses in advanced decomposition stages, as H. illucens spends relatively more time on the carcasses than most dipterans.

Fresh and Dry Mass Estimates of Hermetia illucens (Linnaeus, 1758) (Diptera: Stratiomyidae) Larvae Associated with Swine Decomposition in Urban Area of Central Amazonia.

Information on biomass is substantial for calculating growth rates and may be employed in the medicolegal and economic importance of Hermetia illucens (Linnaeus, 1758). Although biomass is essential to understanding many ecological processes, it is not easily measured. Biomass may be determined by directly weighing or indirectly through regression models of fresh/dry mass versus body dimensions. In this study, we evaluated the association between morphometry and fresh/dry mass of immature H. illucens using linear, exponential, and power regression models. We measured width and length of the cephalic capsule, overall body length, and width of the largest abdominal segment of 280 larvae. Overall body length and width of the largest abdominal segment were the best predictors for biomass. Exponential models best fitted body dimensions and biomass (both fresh and dry), followed by power and linear models. In all models, fresh and dry biomass were strongly correlated (>75%). Values estimated by the models did not differ from observed ones, and prediction power varied from 27 to 79%. Accordingly, the correspondence between biomass and body dimensions should facilitate and motivate the development of applied studies involving H. illucens in the Amazon region.

Potential Effects of Climate Change on Ecological Interaction Outcomes Between Two Disease-Vector Mosquitoes: A Mesocosm Experimental Study.

The objective of this study was to experimentally assess the effects of different climate change scenarios on the outcomes of interactions between Aedes aegypti (L.) and Culex quinquefasciatus (Say) (Diptera: Culicidae) larvae. The experimental design maintained a constant density of specimens while the proportion of the species in different experimental climate change scenarios varied. Our results indicate that survival of the two species was not affected, but larval development and pupation times decreased under elevated atmospheric CO(2) concentration and high air temperature. In climate change scenarios with both species together, the survival of Ae. aegypti increased and its larval development time decreased with increasing density of Cx. quinquefasciatus. This may be attributed to the effects of intraspecific competition being more significant than interspecific competition in Ae. aegypti. Our study also reveals that climatic changes may affect the patterns of interactions between Cx. quinquefasciatus and Ae. aegypti. Alterations in climatic conditions changed the response of context-dependent competition, indicating the importance of studies on how ecological interactions will be affected by projected future climatic change.

Description of immature stages and development time of Paralucilia paraensis (Mello) (Diptera: Calliphoridae) associated with the decomposition of a partially submerged swine carcass.

We report on the bionomics and morphology of the immature stages of Paralucilia paraensis (Mello) (Diptera: Calliphoridae). Observations were made on a daily basis for 10 h (from 8 a.m. to 6 p.m.) on a 45-kg pig (Sus scrofa) whose carcass had been partially submerged in a stream of water on the 21st of November 2009, in a forested area of Manaus, Amazonas, Brazil. The collected specimens were placed in plastic vials and transferred to a growth chamber maintained at room temperature. Adults of P. paraensis were collected on the carcass between the 3rd and the 18th days. A total of 13 gravid females were captured; from these, 1,240 eggs were obtained and yielded 1,030 larvae that developed into 879 adults. The average time required for hatching was 13 h. On average, the larvae reached the second instar within 13 h, third instar within 18 h, and pupae within 46 h. The pupal stage lasted 96 h. The complete development time was 216 h. This is the first report on the development time and morphology of immature stages of P. paraensis in forested areas. Therefore, these results provided information for the implementation of future forensic studies in the state of Amazonas.