A comparison of commercial light-emitting diode baited suction traps for surveillance of Culicoides in northern Europe

Abstract

BackgroundThe response of Culicoides biting midges (Diptera: Ceratopogonidae) to artificial light sources has led to the use of light-suction traps in surveillance programmes. Recent integration of light emitting diodes (LED) in traps improves flexibility in trapping through reduced power requirements and also allows the wavelength of light used for trapping to be customized. This study investigates the responses of Culicoides to LED light-suction traps emitting different wavelengths of light to make recommendations for use in surveillance.MethodsThe abundance and diversity of Culicoides collected using commercially available traps fitted with Light Emitting Diode (LED) platforms emitting ultraviolet (UV) (390 nm wavelength), blue (430 nm), green (570 nm), yellow (590 nm), red (660 nm) or white light (425 nm – 750 nm with peaks at 450 nm and 580 nm) were compared. A Centre for Disease Control (CDC) UV light-suction trap was also included within the experimental design which was fitted with a 4 watt UV tube (320-420 nm). Generalised linear models with negative binomial error structure and log-link function were used to compare trap abundance according to LED colour, meteorological conditions and seasonality.ResultsThe experiment was conducted over 49 nights with 42,766 Culicoides caught in 329 collections. Culicoides obsoletus Meigen and Culicoides scoticus Downes and Kettle responded indiscriminately to all wavelengths of LED used with the exception of red which was significantly less attractive. In contrast, Culicoides dewulfi Goetghebuer and Culicoides pulicaris Linnaeus were found in significantly greater numbers in the green LED trap than in the UV LED trap. The LED traps collected significantly fewer Culicoides than the standard CDC UV light-suction trap.ConclusionsCatches of Culicoides were reduced in LED traps when compared to the standard CDC UV trap, however, their reduced power requirement and small size fulfils a requirement for trapping in logistically challenging areas or where many traps are deployed at a single site. Future work should combine light wavelengths to improve trapping sensitivity and potentially enable direct comparisons with collections from hosts, although this may ultimately require different forms of baits to be developed.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0846-x) contains supplementary material, which is available to authorized users.

Comparison of different light sources for trapping Culicoides biting midges, mosquitoes and other dipterans

“…scoticus, the main relevant BTV vectors across Europe (Purse et al, 2005), was green, which agrees with Hope et al (2015) observations, where C. obsoletus/C. scoticus and C. brunnicans were collected in higher numbers using the same colour LED traps.…”

“…Culicoides species exhibited a similar response to green, blue and UV LEDs, but seemed to respond poorly to red (Bishop et al, 2004;Hope et al, 2015). Only 9 species were collected using red lights while the other wavelengths attracted more than 15 species.…”

“…LED tests on Culicoides biting midges have been done in Australia (Bishop et al, 2004(Bishop et al, , 2006, Africa (Tchouassi et al, 2012), and most recently in South America (Silva et al, 2015) and Europe (Hope et al, 2015). Only a few publications describe the attractiveness of LEDs to different Diptera species.…”

Culicoides species as potential vectors of African horse sickness virus in the southern regions of South Africa

“…Although a high incidence of wind in the area could have influenced flight activity, these lower mean numbers may have been the result of the use of less powerful 12-V traps Probst et al, 2015). Similarly, the overall lower numbers of Culicoides collected during 2015-2016 may be ascribed to the use of LEDs, which were recently shown to be at least four times less powerful than conventional fluorescent lights with respect to attracting European Culicoides species (Hope et al, 2015;Wakefield et al, 2016). These more energy-conservative 12-V traps did allow sampling over a wider and more diverse geographical area independent of 220-V electricity.…”

The dying of the light: crepuscular activity in Culicoides and impact on light trap efficacy at temperate latitudes

“…In the modern era, Culicoides biting midges are generally collected using various models of the suction light trap (Bishop et al ., ; Cohnstaedt et al ., ; Venter et al ., ; Hope et al ., ). The advantages of the light trap include that it is cost‐effective, requires a minimum of effort from the investigator and, as a relative method, provides copious amounts of data.…”