Assessing the efficiency of UV LEDs as light sources for sampling the diversity of macro-moths (Lepidoptera)

Light trapping is the most widely used tool for determining the diversity of nocturnal Lepidoptera, but UV LEDs have yet to be used as light sources for the large-scale monitoring of Lepidoptera. We assessed the efficiency of this novel light source for sampling moths using a Heath type moth equipped with a strip of 150 high brightness UV LEDs (emission peak 398 nm, ~ 15 W) powered by a 12 V battery. We compared the number of individuals, the number of species and the Geometridae / Noctuidae ratio recorded for the samples collected using UV LED traps with those collected in two monitoring programs carried out in the same geographic region using two different light sources: a 200 W incandescent lamp (Rothamsted trap) and a 160 W mercury vapour lamp (manual catch). The total catch consisted of 61,120 individuals belonging to 699 species. The species richness rarefaction curves revealed that the Rothamsted trap collected fewer species and individuals than UV LED traps. Furthermore, the median numbers of species and individuals caught by UV LED traps fell within the range of those caught by mercury vapour lamp traps. In addition, the community composition recorded using incandescent lamps and UV LEDs was similar. The data obtained using UV LED traps, in absolute terms and in comparison with the other light sources and different sampling methods, clearly reveal that this light source is suitable for sampling macro-moth communities. For field work UV LEDs have many advantages, as they are resistant to mechanical damage, easily protected from heavy rain and energy efficient.