Click beetle larvae within the genus Agriotes (Coleoptera: Elateridae), commonly known as wireworms, are abundant ground-dwelling herbivores which can inflict considerable damage to field crops. In Central Europe up to 20 species, which differ in their distribution, ecology and pest status, occur in arable land. However, the identification of these larvae based on morphological characters is difficult or impossible. This hampers progress towards controlling these pests. Here, we present a polymerase chain reaction (PCR)-based approach to identify, for the first time, 17 Agriotes species typically found in Central Europe. Diagnostic sequence information was generated and submitted to GenBank, allowing the identification of these species via DNA barcoding. Moreover, multiplex PCR assays were developed to identify the nine most abundant species rapidly within a single-step reaction: Agriotes brevis, A. litigiosus, A. obscurus, A. rufipalpis, A. sordidus, A. sputator, A. ustulatus, A. lineatus and A. proximus. The latter two species remain molecularly indistinguishable, questioning their species status. The multiplex PCR assays proved to be highly specific against non-agrioted elaterid beetles and other non-target soil invertebrates. By testing the molecular identification system with over 900 field-collected larvae, our protocol proved to be a reliable, cheap and quick method to routinely identify Central European Agriotes species.

Agriotes wireworms (Coleoptera: Elateridae) are abundant soil-dwelling herbivores which can inflict considerable damage to field crops. In Europe up to 40 species occur, differing in their ecology and pest status. Their distribution in the larval stage, however, has rarely been assessed because of the considerable effort in collecting wireworms and the difficulties in identifying them to species-level. Here, we examined the occurrence of Agriotes wireworms in Austrian agricultural land with regard to their association with climatic and soil parameters. Using a molecular identification system, 1348 field-collected larvae from 85 sites were identified to species-level. Three species, Agriotes obscurus, Agriotes brevis, Agriotes ustulatus, and two that could not be discerned molecularly (Agriotes lineatus and Agriotes proximus), were assigned to two ecological groups: (i) A.brevis/A. ustulatus, found in areas with a warmer, drier climate and alkaline soils, and (ii) A. obscurus/A. lineatus/proximus which occur mainly at higher altitude characterised by lower temperatures, higher precipitation and acidic, humus-rich soils. Agriotes sputator was abundant throughout Austria, confirming its euryoecious nature. Only one larva of Agriotes litigiosus was found, prohibiting further analysis. These data contribute to a characterisation of species-specific traits in Agriotes larvae in agricultural land, an important prerequisite to develop efficient control strategies for these wireworms.Electronic supplementary materialThe online version of this article (doi:10.1007/s10340-011-0393-y) contains supplementary material, which is available to authorized users.