Small Hive Beetle (Coleoptera: Nitidulidae) and the Yeast, Kodamaea ohmeri: A Facultative Relationship Under Laboratory Conditions.

The small hive beetle, Aethina tumida Murray, is a pest of honeybees, Apis mellifera L. (Hymenoptera: Apidae). We investigated the significance of its association with the yeast, Kodamaea ohmeri (Etchells & Bell) (Ascomycota: Saccharomycotina), in laboratory experiments. The mean (± SEM) viability of A. tumida eggs was 84 (± 3)%; the viability was not affected if eggs were separated from clutches or if mucilage containing K. ohmeri was removed from the egg surface. Life tables of conventional (= K. ohmeri contaminated) A. tumida and K. ohmeri-free A. tumida revealed no differences in stage-specific mortality between the treatments; in both cases, the highest mortality occurred in the first larval instar. There was no significant difference in the initial egg production of conventionally reared and K. ohmeri-free A. tumida under laboratory conditions. The volatile profiles of pollen dough (Bee Build) fed on by conventional and K. ohmeri-free A. tumida larvae were qualitatively and quantitatively different; the volatiles produced by pollen dough fed on by conventional A. tumida were more attractive to adult beetles. There was a clear difference between growth of K. ohmeri on pollen dough substrate in the presence and absence of A. tumida. Results suggest that this association is facultative for A. tumida under laboratory conditions but has benefit for the yeast associate, K. ohmeri. A clearer understanding of the nature of this fungus-insect association is essential for the development of management strategies for this pest, especially in the development of fermentate-based attractants in trapping systems.

Horizontal transmission of Metarhizium anisopliae (Hypocreales: Clavicipitacea) and the effects of infection on oviposition rate in laboratory populations of Musca domestica (Diptera: Muscidae).

BACKGROUND: Effective control of house fly, Musca domestica (L.), populations currently relies on the use of chemical insecticides in most situations. Entomopathogenic fungi such as Metarhizium anisopliae (Metschn.) Sorokin may provide an alternative to chemicals and their efficacy may be enhanced by autodissemination amongst flies. This study assessed the capacity of M. anisopliae for transmission between adult M. domestica flies and the effects of infection on the fecundity of females. RESULTS: Metarhizium anisopliae was transmitted between adult M. domestica with 91.67-100% mortality resulting across the three ratios of infected: non-infected flies tested (1:2, 1:5 and 1:10). The mean lethal time (LT50 ) for female recipients mixed with infected male donor flies at the three ratios was 3.95, 4.79 and 5.65 days, respectively, whereas for male recipients mixed with infected female donors at the same ratios the LT50 was 4.98, 5.98 and 7.44 days, respectively. Infection with M. anisopliae significantly reduced the reproductive capacity of female flies during the first 4 days of infection, with 25% fewer eggs oviposited by infected flies than by those that were uninfected. CONCLUSION: Autodissemination among house flies and reduction in oviposition in the early stages of infection could contribute significantly to the effectiveness of M. anisopliae used in biocontrol programmes. © 2017 Society of Chemical Industry.