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Abstract: We describe details of the mate finding strategy of drones of the European hornet, Vespa crabro, and present evidence for the involvement of sex pheromones. Tests were carried out with free flying drones in natural habitats. Males patrolled the nest site itself, as well as nearby nonresource-based sites, without showing territorial behavior. Patrolling was restricted to sunny spots in the vegetation, and thus, the locations changed throughout the day. Drones were attracted to both caged gynes and to dead workers treated with gyne extracts, indicating the presence of a female-produced sex attractant. Treated workers also elicited copulation attempts by the attracted drones. Extracts from gynes, workers, and drones contained exclusively cuticular lipids, and the profile from gynes was much more diverse than that of workers and drones. The most striking differences observed related to the alkenes, monomethyl- and dimethylalkanes. The results provide a lead for potential attracting and copulation-releasing semiochemicals in V. crabro.

African honeybees, Apis mellifera, are characterised by frequent disturbance-induced absconding. However, the effectiveness in preparation before such disturbance-induced absconding has not been rigorously quantified yet. We investigated the effectiveness of preparation for disturbance-induced absconding by evaluating colony phenotypes prior to and after absconding in ten colonies of the Cape honeybee, A. m. capensis. Seven non-absconding colonies at the same apiary were used as controls. While seven absconded colonies left neither stores nor brood behind, three colonies abandoned only a small area of honey, pollen, open or capped brood. At the end of the observations, the control colonies still had pollen and honey stores and brood. The mean reduction rate between a major disturbance and the absconding event was 0.052 ± 0.018 cm2stores and open brood per worker per day. Our results demonstrate that disturbance-induced absconding can also occur with preparation, if the disturbance is not highly destructive and enough time for preparation is available. We conclude that Cape honeybee colonies can show a considerable high effectiveness in their preparation before disturbance-induced absconding, which limits the loss of colony resources. In light of the general high mobility of African honeybee colonies such an efficient behaviour is probably adaptive.

In this study, we evaluated the potential use of entomopathogenic nematodes as a control for the beetle Aethina tumida Murray (Coleoptera: Nitidulidae). In particular, we conducted 1) four screening bioassays to determine nematode (seven species, 10 total strains tested) and application level effects on A. tumida larvae and pupae, 2) a generational persistence bioassay to determine whether single inoculations with nematodes would control multiple generations of A. tumida larvae in treated soil, and 3) a field bioassay to determine whether the nematodes would remain efficacious in the field. In the screening bioassays, nematode efficacy varied significantly by tested nematode and the infective juvenile (IJ) level at which they were applied. Although nematode virulence was moderate in screening bioassays 1–3 (0–68% A. tumida mortality), A. tumida mortality approached higher levels in screening bioassay 4 (nearly 100% after 39 d) that suggest suitable applicability of some of the test nematodes as field controls for A. tumida. In the generational persistence bioassay, Steinernema riobrave Cabanillas, Poinar & Raulston 7-12 strain and Heterorhabditis indica Poinar, Karunaka & David provided adequate A. tumida control for 19 wk after a single soil inoculation (76–94% mortality in A. tumida pupae). In the field bioassay, the same two nematode species also showed high virulence toward pupating A. tumida (88–100%) mortality. Our data suggest that nematode use may be an integral component of an integrated pest management scheme aimed at reducing A. tumida populations in bee colonies to tolerable levels.