Nicrophorus investigator Zetterstedt, 1824
POLYPHAGA Emery, 1886
STAPHYLINOIDEA Latreille, 1802
NICROPHORINAE Kirby, 1837
Nicrophorus Fabricius, 1775
A very widespread Holarctic species; in the Palaearctic region extending from Europe through Asia Minor and Russia to Siberia, China and Japan, and in the Nearctic region occurring across northern parts of North America, Canada, Alaska and the Aleutian Islands and extending south to northern parts of Mexico in the east. The species occurs throughout Europe; it is generally common in central and northern regions where it reaches far above the Arctic Circle in Scandinavia, but otherwise rather local, it is known from only a few of the Mediterranean islands and is absent from North Africa. Here it is generally common throughout the UK including the Western Isles and Orkney but apparently rather more local across Ireland. In central Europe it occurs mostly in wooded habitats, including Boreal forests, and only rarely in the open, but in northern regions it occurs more generally, in open woodland, grassland, parkland, heathland and coastal habitats with no apparent preference for soil type or aspect. Adults are present year-round; they overwinter in soil etc. and are active from March or April until October, peaking in abundance from July until September and, unlike most of our members of the genus, breeding occurs later in the season, usually from July, and the main overwintering stage is the pre-pupa. The biology is typical of the genus; adults meet at host material which they will contest with others as they arrive, and once they have ‘claimed’ their carrion will mate and prepare it for burial by removing any fur or feathers and secreting a preserving fluid across the surface. Great care is taken in preparing the corpse; it may be moved to a more suitable site and then it will be worked into a ball-shape before being buried, from below, to a depth down to 60cm. The female will then lay eggs in the ground close by, usually with the male in attendance and this close bond will remain until the larvae are fully grown; the pair is strongly dedicated so that should one die the other will take over feeding and looking after the larvae. Larvae move to the carrion where they will be guarded and fed by the adults throughout their development, they grow rapidly and after only a few weeks they move into the soil to pupate. The life-cycle is rapid but there is only a single generation each year. Various species of mite (mostly Poecilochirus) are almost always present on the beetles, these also develop in carrion and so rely on the beetles for dispersal but they are also beneficial in that they predate small insects and nematodes and so reduce competition for host material, and this symbiosis continues as the new generation of mites will attach to adult beetles as they eclose and will remain in place until new host material is found. The usual host material is small mammals and birds but adults may be attracted to any type of carrion as well as decaying fungi and plant material. During the winter they may be found among decaying fungi and at carrion etc. Adults are diurnal and nocturnal, they fly well and are the most frequently recorded of our species at light traps, they are easily recorded with carrion-baited traps, which they are said to be able to detect up to a mile away, and so are easily recorded.
Nicrophorus investigator 1
Nicrophorus investigator 2
12-22 mm. Large, robust and typical of the genus, body rather shiny black, elytra black with two transverse red bands, the anterior of which usually unite at the suture but this is variable and they may be narrowly separated, antennae black with the last three club segments wholly or substantially red, legs black or with the tibiae and/or tarsi dark brown. Pronotum without marginal golden pubescence. Hind tibiae straight along the inner margin. Distinguished from our other bicoloured species as follows. In N. vespillo the hind tibiae are clearly curved along the inner margin. The antennal club of N. vespilloides is entirely black. N. vestigator has golden pubescence on the pronotal margins. Where the anterior red band is separated at the suture there may be confusion with N. interruptus, but here the abdominal tergites are fringed with golden pubescence, in the present species the tergites are fringed with dark brown or black hairs, only the last tergite sometimes with yellow hairs around the apical margin. Males may be distinguished by the dilated front tarsi.