Rare, or simply overlooked? Practical notes for survey and monitoring of the small glow-worm Phosphaenus hemipterus (Coleoptera : Lampyridae)

Phosphaenus he,hemipterus (Fourcroy, 1785) is considered a very rare glow-worm and has consequently been studied very little. This paper unites the scattered data on the known distribution of P. hemipterus and gives descriptions of habitat use, phenology and activity patterns at recently discovered sites in Belgium. Adult males were found fi om mid-June to mid-July and were most abundant on warm days, with a clear diurnal activity pattern. Only a few adult females were found, mainly around dusk and in or near crevices. Larvae are mainly nocturnal and glow spontaneously as do most lampyrid larvae, but many were also found during the day. The larvae appear to feed only on earthworms. Typical features of the habitat of P. hemipterus are loamy soils and abrupt transitions from dense vegetation into bare patches. Apparently many of these features ale present in areas with severe human disturbance such as in gardens, parks, car parks and at field edges. However, most survey studies on glow-worms are carried out in nature reserves, which may explain why P. hemipterus is mostly missed. The species may actually be not as rare as presumed, and, moreover, it occurs in areas that are not considered important for conservation management.