Seasonal fluctuations in Agriotes spp. (Coleoptera: Elateridae) at two sites in Austria and the efficiency of bait trap designs for monitoring wireworm populations in the soil

Abstract

Wireworms, the larvae of Agriotes spp. (Coleoptera: Elateridae), cause serious damage to a number of crops. To develop an effective management strategy, a reliable method of estimating the abundance of the Agriotes species is needed. This paper describes a trapping study of Agriotes in parts of Austria. Over two years, adult click beetles were monitored using YATLOR sex pheromone traps and wireworms were monitored using bait traps. Also, the efficiency of bait traps with different numbers of perforations was compared. In a location in Upper Austria, A. lineatus was by far the most common species and in a location in lower Austria, the majority of beetles caught were A. ustulatus. A. brevis was common in Upper Austria, but nearly absent in Lower Austria. There were large discrepancies between the species compositions of the adults and larvae caught, suggesting a low efficiency of the bait traps. More larvae were caught in bait traps with greater numbers of holes, but the difference was not statistically significant. Further improvements in bait traps or another sampling method will be needed to accurately estimate the density of wireworms.

Occurrence of Agriotes wireworms in Austrian agricultural land

“…Literature data indicate that the preferred environmental conditions of A. lineatus are comparable to A. obscurus (Kabanov 1975; Langenbuch 1932; Schimmel 1989; Tóth 1984). Indeed, in the present study, larvae of A. lineatus/proximus were found only in northern Austria (Waldviertel–Innviertel), characterised by high mean annual precipitation (see also Landl et al 2010). Agriotes lineatus is known to be hydrophilic and especially moisture-resistant (Langenbuch 1932), and according to Kabanov (1975) these wireworms are able to survive flooding over several days.…”

“…So far, only a few investigations on Agriotes wireworm occurrence have been conducted in Austria (Brunner et al 2005; Landl et al 2010) which depended on laborious and uncertain morphological larval identification. The present study demonstrates the applicability of the molecular identification protocol for large scale surveys: 92% of all collected wireworms were directly identified via multiplex PCRs, which proved to be highly suitable to cover the key Agriotes species present in agricultural land in Central Europe.…”

“…Historically, few studies have focussed on Agriotes wireworm occurrence and species composition in agricultural land (Alekhin 1973; Jossi and Bigler 1997; Landl et al 2010). Most studies have targeted adult male beetles as these can be easily collected in pheromone traps (e.g.…”

“…Furlan and Tóth 2007; Subchev et al 2005; Vernon and Tóth 2007). Although monitoring via pheromone trapping provides an effective means to collect adult male beetles (Tóth et al 2003), there are constraints to this approach: for example, the long-lived larval population in the soil is not necessarily reflected by adult catches (Hicks and Blackshaw 2008; Landl et al 2010). Moreover, pheromones are not available for all Agriotes species, rendering the adult species spectrum incomplete.…”

Control methods and monitoring of Agriotes wireworms (Coleoptera: Elateridae)

“…Regarding the last decade, German extension services have sent more frequently reports about wireworm damages on maize, potatoes, strawberries, fennel, carrots, lettuce, asparagus and onions than in the past. Additionally, reports about wireworm damages are increasing in many European countries such as Austria (Landl et al 2010), Switzerland (Jossi et al 2008), the Netherlands (Ester & Huiting 2007), Italy (Furlan et al 2002), Spain (Eizaguirre et al 2005) and the UK (Parker 2007). One reason might be a change in agricultural methods due to new programs on pesticide reduction or low tillage farming.…”