Seasonal abundance in necrophagous Diptera and Coleoptera from northern Venezuela

Abstract

A carcass represents an ecosystem for necrophagous insects and other arthropods communities, and the decomposition stages are related to an ecological succession. Several factors are associated with the insects colonization and subsequently, accelerate or retard the decomposition. Some studies confirm the seasonal differences in blowflies and other medicolegal important insects. From 2015 and 2016 during four months was studied the entomofauna associated to a beef biomodel. Insects species abundance from monthly catches was used for richness determination, and the community structure was estimated using diversity and evenness indexes. The monthly precipitation data was used for describing the association between environmental and insects abundance. Were collected 1046 specimens comprises the Order Diptera (97%) and including Calliphoridae, Muscidae, Piophilidae, Sarcophagidae and Otitidae; in Coleoptera (3%): Dermestidae, Cleridae and Staphylinidae. Were found twelve species: Chrysomya megacephala, C. albiceps, Lucilia cuprina, Cochliomya macellaria, Musca domestica, Ophyra aenescens, O. chalcogaster, Atherigona orientalis, Piophila casei, Dermestes maculatus, Necrobia rufipes and Belonuchus rufipennis. The highest insects abundance and richness were registered in May, February and November, while the lowest values were found in August. The Calliphoridae and Muscidae abundance and richness increase between November and May that correspond to ending of rainy season and beginning of the dry season, while the values decrease in August that correspond to the rainy season. Our study represents the first investigation to determine the seasonal variation of medicolegal important insects in Venezuela. However are necessary more studies that consider different habitat type (forests, savannas, etc) to determine the insects occurrence among different decomposition stages.