Nicrophorus vespilloides Herbst, 1783
This Holarctic species is generally the most common member of the genus; it occurs throughout Europe to the far north of Scandinavia and east through Siberia to China and Japan and is widespread across the northern United States and southern Canada. Throughout the Palaearctic region it occurs from lowland to alpine altitudes in a wide range of habitats such as forests, moorland, parkland and even gardens but in the Nearctic it is restricted to sphagnum bogs, marshes and upland marginal habitats; this has been attributed to competition with the largely forest-dwelling Nicrophorus defodiens Mannerheim, 1846. In the UK it is generally common throughout the mainland and occurs on most of the islands including Orkney. Adults occur year-round and are active from April or May until late into the autumn, peaking in May and again in late summer; overwintered adults appear in the spring and breed after a period of feeding, many of these survive the summer and are present when the next generation of adults appears from July or August, causing a large peak in numbers. Both sexes are strongly attracted to the odour of carrion and will fly long distances to find it, females arriving first will fight and release sex pheromones to attract males which soon arrive, fighting continues between males and females until all but a single pair are driven off. If several males arrive at the carrion first they will usually cooperate in burying it and then begin fighting until a female arrives. When a single pair remains they will either dig down to the carrion or, if it is still on the surface, begin stripping it of fur or feathers and bury it. During this process the carrion is formed into a rather homogenous mass and coated with anal secretions which are powerfully antibiotic and help preserve it until the larvae begin feeding. While the carrion is being buried the phoretic mites, which most of the beetles carry in numbers, enter the host material and feed on diptera eggs and larvae which usually appear very quickly, they will also attack the beetle eggs which may be why they are laid in galleries in the soil near the host, and this further preserves the larval food source. Several small groups of eggs are laid in chambers in the soil and hatch within a week or two, the small larvae crawl into
Nicrophorus vespilloides 1
Nicrophorus vespilloides 2
Nicrophorus vespilloides 3
the host material where they are fed by both parents during the first instar when their mouthparts are small and soft. Second and third instar larvae feed independently but both parents usually remain to guard them from predators attracted to the decaying carrion. Each instar develops over a week or two and when fully-grown they enter the soil to pupate, this stage lasts about 20 days and freshly-eclosed adults remain in place for a few days to harden. Before leaving they return to the carrion where fresh mites become attached and then they leave. Adults are mostly nocturnal and may be attracted to light throughout the spring and summer, they are frequent at decaying fungi in the autumn and occasionally occur elsewhere e.g. we have found them repeatedly among aggregations of diptera larvae under logs in our local woods, they are readily attracted to carrion-baited pitfall traps, often in numbers and often alongside other carrion-frequenting beetles.
Adults vary widely in size, from 12mm to about 20mm, but are otherwise very distinct among our fauna, the only possible confusion might be with other red-banded Nicrophorus but the present species is distinct in having entirely black antennae; in our other species the terminal segments are orange or red.