Developmental models of the carrion beetle Thanatophilus rugosus (Linnaeus, 1758) (Coleoptera: Silphidae)

Coleoptera are currently considered a fundamental tool to help solve criminal investigations, allowing forensic entomologists to estimate post-mortem intervals and obtain other ecology-related information. Thanatophilus rugosus (Linnaeus, 1758) is an important necrophagous beetle distributed through most of the Palaearctic region, where it is readily found on human bodies and animal carcasses. In this study, the new thermal summation models for all the developmental stages of Thanatophilus rugosus are provided. Beetles were reared at six different constant and ecologically relevant temperatures (12, 14, 16, 18, 20, and 22 °C), and their developmental times were measured. Thermal summation constants were calculated for each developmental stage (egg, three larval instars, post-feeding stage, and pupa).

Influence of Diet on Development and Survival of Thanatophilus rugosus (Coleoptera: Silphidae)

This study examined the effects of various diets on the development time and survival of the carrion beetle Thanatophilus rugosus (Fabricius, 1775). We attempted to find the best diet for rearing the species in laboratory conditions for entomological research and forensic purposes, and to further understand its feeding habits. The larval stages were monitored while feeding on three types of meat under a constant temperature. We discovered that the shortest development time in total was achieved in larvae fed with pork liver, followed closely by pork muscle. The longest development and lowest survival rates were observed when introducing a chicken diet. We were also able to identify specific stages during which the diet significantly affected the development.

Partitioning resources through the seasons: abundance and phenology of carrion beetles (Silphidae) in southeastern Ontario

The coexistence of ecologically similar species is thought to require resource partitioning to minimize competition. Phenological, seasonal differences in activity may provide an important axis for resource partitioning. Here, we test for evidence of seasonal differences in activity within a diverse guild of carrion beetles (Silphidae) in a habitat preserve on the Frontenac Arch, southeastern Ontario, Canada using a large-scale survey during their active seasons (April to October). We then used generalized additive models to test for differences in seasonal abundance among eight co-occurring carrion beetle species, including five species of burying beetles (Nicrophorinae: Nicrophorus Fabricius, 1775) and three species from the Silphinae subfamily. Consistent with previous work, all species showed seasonal variation in abundance, with peak abundance of most species occurring between June and August. All but one species (Nicrophorus sayi Laporte, 1840) showed positive relationships between abundance and temperature. We find evidence consistent with seasonal partitioning of resources among Nicrophorus habitat generalists that could potentially reduce competition for limited carrion resources. In contrast, we find little evidence for seasonal differences in abundance among Nicrophorus habitat specialists, which instead may partition resources spatially. Overall, our results provide evidence consistent with an important role for seasonal resource partitioning among carrion beetle species that show higher levels of spatial (habitat) overlap within a temperate beetle guild.

Oiceoptoma tangi (Coleoptera: Silphidae: Silphinae), a new species of carrion beetle from eastern China

A new species, Oiceoptoma tangi Sommer, Růžička, Nishikawa & Schneider, new species, from Zhejiang Province, China, is described and illustrated. The new species is closely related to O. subrufum (Lewis, 1888), distributed in Central and North-eastern China, the Korean Peninsula, Far East of Russia and Japan, and to O. nigropunctatum (Lewis, 1888), endemic to Japan. All three species are keyed, and distribution maps of all three species are presented.

Effect of Granulometric Composition of the Soil on the Occurrence of Carrion Beetles (Coleoptera: Silphidae)

The entomological material was collected in the years 2009–2012 and 2014 from 13 different habitat types from three localities in south-eastern Poland. In total, 11,095 Silphidae were collected. This study examined whether the percentage of individual soil granulometric fractions was significantly related to the total abundance of collected Silphidae and individual carrion beetle species. A positive correlation and a statistically significant correlation were found between the total number of specimens collected and the share of the mechanical fraction with a diameter of 0.05–0.002 mm (silt fraction). In three species, a statistically significant correlation was demonstrated between the number of collected Silphidae and the share of the mechanical fraction with a diameter of 2–0.05 mm (sand fraction). The two species Phosphuga atrata atrata and Nicrophorus vespilloides the correlation was positive. A statistically significant relationship was also observed for Thanatophilus sinuatus, but the correlation was negative. With regard to the mechanical fraction with a diameter <0.002 mm (clay fraction), a statistically significant relationship was demonstrated for Oiceoptoma thoracicum and for Nicrophorus vespilloides for which the correlation was negative. However, a positive correlation was found for T. sinuatus in this case.

A case of a Pustulated Carrion Beetle (Nicrophorus pustulatus, Coleoptera: Silphidae) burying live Tree Swallow (Tachycineta bicolor, Passeriformes: Hirundinidae) nestlings under the nest

The ecology of Pustulated Burying Beetle (Nicrophorus pustulatus, Coleoptera: Silphidae) appears distinct among Nicrophorus species, with evidence of it parasitizing snake eggs and foraging primarily above the ground and into the forest canopy. Here we document an extension of its aberrant ecology and behaviour: a case of N. pustulatus burying 2-day-old live and dead nestlings of Tree Swallow (Tachycineta bicolor, Passeriformes: Hirundinidae) under the nest, behaviour consistent with the early stages of breeding in N. pustulatus. Based on different levels of decomposition, we suspect that N. pustulatus responded to one dead swallow nestling in the brood of five and went on to bury all of the nestlings at the bottom of the nest box. The observation provides the first evidence, to our knowledge, of Nicrophorus burying live vertebrates.

Developmental Models of the Forensically Important Carrion Beetle, Thanatophilus sinuatus (Coleoptera: Silphidae)

Carrion beetles of genus Thanatophilus (Leach, 1815) are an important group of necrophagous insects, with great potential for forensic entomology in temperate zones of Africa, America, Asia, and Europe. Developmental models for majority of Thanatophilus species remain unknown. In this study, we will provide new thermal summation models for all the developmental stages of Thanatophilus sinuatus (Fabricius, 1775), one of the most abundant and widespread species of the genus. The beetles were bred at seven different constant temperatures, and developmental time was measured for each developmental stage (egg, three larval instars, postfeeding stage, and pupa). Temperature–sex influence was tested, and thermal summation constants were calculated to be used for postmortem interval estimation during criminal investigations.