Dispersal of click-beetles in agricultural fields: a mark-recapture study

Abstract: Wireworms remain one of the more pernicious soil pests in field cropping systems. Itis apparent that the adult stage – click beetles – are more widespread in agricultural landscapesthan the wireworms. Dispersal of adults has become of interest as alternative approaches toinsecticides are sought. In this paper we report part of a series of studies to determine whatfactors may affect click beetle dispersal across fields. Two experimental sites (wheat and fallow)were established with arrays of traps. Batches of marked male Agriotes lineatus, and male andfemale A. obscurus were released at the centre of each field. Traps were examined on the day ofrelease and daily thereafter to recover marked beetles giving time periods of 1 to 561 hrs afterrelease. Data for both sites and all release events were analysed as direction or distance travelledfrom the release point using univariate methods. Only 9.8% of the deviance in directional datacould be accounted for, but 22.1% for distance travelled. Female A. obscurus travelledsignificantly less distance than did males but there was no difference between males of the twospecies. Greater distances were travelled in the wheat than fallow field and the date of releaseaffected both distance and possibly travel direction.