Dose–response to sex attractants, and flight phenology of click beetle species (Elateridae) native to eastern North America

Females of most species of click beetles (Coleoptera: Elateridae) emit sex pheromones that attract males, and these chemicals can be utilized in monitoring and managing pest species. Here, we conducted dose-response trials with sex attractants of 5 elaterid species native to Illinois. Synthesized attractants were dispensed from polyethylene sachets, with doses of 0 (solvent control), 1, 3.3, and 10 mg. For 2 Gambrinus species, only traps baited with 10 mg doses of limoniic acid captured significantly more beetles than did control traps. However, for another 3 elaterid species, traps baited with 3.3 and 10 mg of attractants captured more beetles than did control traps, including Elater abruptus Say (attractant 5-methylhexyl [Z]-4-decenoate), Melanotus ignobilis Melsheimer (11-dodecenyl butyrate), and Parallelostethus attenuatus (Say) (1,8-octanediol dihexanoate). A separate field experiment, that tested 2 types of dispensers loaded with attractants, showed that traps baited with polyethylene sachet dispensers captured significantly more males of E. abruptus and P. attenuatus than did traps baited with rubber septa. We also assessed seasonal and daily activity periods of E. abruptus, M. ignobilis, and P. attenuatus, using attractant-baited panel traps. Flight periods of all 3 species were generally unimodal and confined to the summer months. Diel activity periods, assessed with attractant-baited panel traps fitted with collection jars that rotated at intervals of 1 to 2 h, showed that males of E. abruptus and P. attenuatus were primarily diurnal, flying from early morning through the evening, whereas males of M. ignobilis were nocturnal.