Bisexual lures and their comparison with synthetic sex attractants for trapping Orthosia species (Lepidoptera: Noctuidae)

Two bisexual lures have been developed using iso‐amyl alcohol plus acetic acid combined with red wine extract (semisynthetic bisexual lure, SBL), or synthetic floral compounds (FLO) for trapping of noctuid moths with early spring activity of adults. Orthosia species were attracted by the tested semi‐synthetic and synthetic lures indicating the possible role of the fermenting liquids and floral compounds in the feeding of these species. Bisexual lures attracted generally a lower number of individuals than the synthetic sex attractants of the given species, except for O. cerasi where FLO lures were more attractive than the sex attractant. Bisexual lures caught both sexes and females composed a sizable percentage of the catch. Since traps baited with different types of bisexual lures provided similar data on sex ratios, thus these presumably reflected the actual sex ratio of the given population. The use of these bisexual lures, especially of FLO in case of Orthosia spp., can be useful in surveys in which the capture of females and data on sex ratios are indispensable, for example in population dynamic and polyandry surveys. In contrast, in case of low population densities, the use of sex attractant lures seem to be still more efficient.