The Effect of Temperature and Laboratory Rearing Conditions on the Development of Dermestes maculatus (Coleoptera: Dermestidae).

Experiments were conducted to study the life cycle of Dermestes maculatus and to establish the total developmental time and the developmental time of immature stages, in relation with six different temperatures. We also analyzed the variations in size, morphology, and other indicators of temporal variation during life cycle of D. maculatus, in relation with temperature. One hundred larvae were selected per experiment, reared individually. The remaining larvae were reared to evaluate and establish temporal variations among the instars (length, cephalic width, and dry weight). In all trials, survivorship was greater than 50% and seven larval instars were found. Data of the average developmental time of immature stages and of the total cycle, at different temperatures, are provided. This is of relevance when estimating particularly, a minimum PMI. No relation between morphometric parameters and temperature was found, suggesting that other random factors may have been involved. Thus, this indicates that the method of isomegalen diagrams could not be used for calculating PMI.

Associational Patterns of Scavenger Beetles to Decomposition Stages.

Beetles associated with carrion play an important role in recycling organic matter in an ecosystem. Four experiments on decomposition, one per season, were conducted in a semirural area in Bahía Blanca, Argentina. Melyridae are reported for the first time of forensic interest. Apart from adults and larvae of Scarabaeidae, thirteen species and two genera of other coleopteran families are new forensic records in Argentina. Diversity, abundance, and species composition of beetles showed differences between stages and seasons. Our results differed from other studies conducted in temperate regions. Four guilds and succession patterns were established in relation to decomposition stages and seasons. Dermestidae (necrophages) predominated in winter during the decomposition process; Staphylinidae (necrophiles) in Fresh and Bloat stages during spring, summer, and autumn; and Histeridae (necrophiles) and Cleridae (omnivores) in the following stages during those seasons. Finally, coleopteran activity, diversity and abundance, and decomposition rate change with biogeoclimatic characteristics, which is of significance in forensics.

Marks caused by the scavenging activity of Necrobia rufipes (Coleoptera: Cleridae) under laboratory conditions.

Insects are an important group involved in carrion consumption and are thus of forensic interest. In the laboratory we studied the taphonomic marks that Necrobia rufipes (Cleridae) can produce. Pig trotters were exposed to adult beetles at 21 ± 3 °C and 12:12 h day/night cycle. We made observations and took photographs every 4-5 days for 12 months. Marks were noted after a month. We found scratches, pits, holes, and tunnels in several kinds of tissue such as integumental, connective and muscular. This work contributes preliminary data of significant application in biology, ecology, anthropology and forensics. Until now, no study has provided taphonomic information with N. rufipes.

Trophic roles of scavenger beetles in relation to decomposition stages and seasons

Carcasses represent a trophic and reproductive resource or shelter for arthropods, which are a representative component of the decomposition process. Four experiments, one per season, were conducted in a semi-rural area of Bahía Blanca, Argentina, to study the trophic roles of cadaveric beetles, evaluating the abundance, composition and dominance during all decomposition stages and seasons. Species of necrophagous, necrophilous and omnivorous habits were found. Abundance, composition and dominance of beetles in relation to their trophic roles changed according to seasons and decomposition stages. Guilds and patterns of succession were established in relation to those periods. Trophic roles could be an indicator of beetle associations with decomposition stages and seasons.

Taphonomic marks on pig tissue due to cadaveric Coleoptera activity under controlled conditions.

The aim of this work was to study taphonomic marks that cadaveric coleopteran can produce under controlled conditions. To evaluate this, pig trotters were initially exposed to adults of Dermestes maculatus De Geer at 21 ± 5°C and a 12:12-h day/night cycle. Observations were made and photographs taken every 4-5 days for 9 months. When feeding and reproducing, D. maculatus produced, in both adult and larvae stages, different types of marks such as holes, striations, scratches, and pits in several kinds of tissue such as integumental, connective, and muscular, in both their fresh and dried stages. Bite marks were also evident. The results in this study provide not only taphonomic but also biological and forensic information. This is the first time that this kind of experiment has been performed.

Un caso de miasis humana por cochliomyia hominivorax (díptera: calliphoridae) asociado a pediculosis en Mendoza, Argentina / A case of human myiasis by cochliomya hominivorax (díptera: calliphoridae) associated with pediculosis in Mendoza, Argentina

Un paciente, adulto, masculino, presentaba al momento de la consulta una severa infestación por Pediculus humanus capitis y una lesión en la cabeza de donde emergían larvas. El material extraído de la herida del paciente correspondió a Cochliomyia hominivorax. En este caso clínico, las lesiones producidas por el rascado del propio paciente permitieron atraer moscas C. hominivorax las que depositaron sus huevos en ellas de donde eclosionaron sus larvas que ocasionaron la miasis cutánea.