Macro‐moth families differ in their attraction to light: implications for light‐trap monitoring programmes

Abstract

Light traps are used to make inferences about local macro‐moth communities, but very little is known about the efficiency with which they attract moths from varying distances, and how this may differ among families. We released 731 marked individuals, from three of the most common and species‐rich macro‐moth families, at several distances from low‐wattage actinic light traps in open and woodland habitat. Logistic regression showed family‐specific sampling areas: erebids were attracted from up to 27 m, geometrids from up to 23 m, and noctuids from up to 10 m from the light source, with these distances corresponding to a 5% recapture rate. Sampling size was also family‐specific: a maximum of 55% of erebids, 15% of geometrids, and 10% of noctuids were predicted to be trapped when flying near (0–1 m) light traps. Our study demonstrates that weak light traps: (i) have remarkably local sampling ranges, resulting in samples that are highly representative of the local habitat, and (ii) attract small, and family‐specific proportions of individuals within these ranges. We suggest that the local sampling ranges of weak light traps make them excellent tools to monitor nocturnal macro‐moth communities. As trap efficiency differs among macro‐moth families, care must be taken in relating the abundance of the sample to absolute local abundance. Frequent sampling can provide adequate data on relative temporal change in the local macro‐moth fauna, however.

Adult Tea Green Leafhoppers, Empoasca onukii (Matsuda), Change Behaviors under Varying Light Conditions

“…Considering that the present study showed that most behavioral activities such as locomotion and searching occur at night, to enhance pest control efficiency, it may be useful to supplement the control of sticky cards that are used during the day with a light control system at night. Although, light traps are now widely used for pest control [6, 52, 53], negative impacts on natural pest enemies remain a concern [54, 55]. Further research will be required to test such control systems to determine whether natural pest enemies, such as spiders, parasitoids, predatory mites, are also trapped leading to a decline in their populations as well as the pest.…”

Pollination by nocturnal Lepidoptera, and the effects of light pollution: a review

“…It has been recognised for many years that shorter wavelengths are, in general, more attractive to moths (Frank, 2006, and references therein); attractiveness appears to peak around wavelengths of 400 nm (violet light; Cowan & Gries, 2009). The degree of attraction and preferred wavelengths both vary between moth taxa (Merckx & Slade, 2014); typically, larger-bodied moths with larger eyes are more likely to be attracted to light dominated by smaller wavelengths (van Langevelde et al, 2011; Somers-Yeates et al, 2013). Variation also appears to exist between sexes; males of some species are significantly more likely to be recorded at light traps than females (Garris & Snyder, 2010), but it is not clear if this is due to stronger male attraction to lights, or males being more active and therefore more likely to move into the zone of influence of a given light (Altermatt et al, 2009).…”

Rewilding European Landscapes

“…23.000 individuals and ca. 380 species rich dataset, we lumped the data from the six sampling rounds for each of the 84 local sites (20 × 20 m, as light traps have relatively small attraction radii: Merckx and Slade 2014). This analysis shows that overall macro-moth species richness is locally richest at woodland sites (mean ± SE: 77.1 ± 4.2), intermediate at meadows (63.2 ± 3.8) and tall shrub (61.7 ± 5.9), and poorest at low shrub sites (51.0 ± 4.3).…”