Aethina tumida: A social parasite of social bees living in matriarchy
Sandra Gabriele Mustafa, Sandra Gabirele Mustafa, , Christian W. W. Pirk
Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa; Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa ; Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
The Small Hive Beetle Aethina tumida MURRAY came in the focus of attention as it was introduced as fast spreading honey-bee (Apis mellifera sp. L.) pest over the globe. It ensures population survival in its new invasive and native South African range by a mass reproduction which may also be the key to its success as invasive species. Mating behaviour and reproduction strategy are logically closely linked and were the core of previous research. Beetles are promiscuous and live in small aggregations within the hive where mating takes place. Several results like females aggressively competing for males and male guarding behaviour may be an indication of a cryptic female choice strategy. Behavioural trials combined with following up molecular genetic analysis were undertaken to undermine this hypothesis. Small mixed gender aggregations were observed for 40 minutes. Each time a second set of males were offered to the same females, males from the first observation removed and observed for 40minutes again. After the experiment males were preserved, females separated and provided with pollen and honey to lay eggs. When offspring had reached an adequate size, it was frozen and preserved, too, together with the females. All samples were analysed with Microsatellite markers. Behavioural analysis of 33 matings already indicate strong choice mechanisms of what ever sort: Males and females mated with up to four different individuals. All except one females got to mate, while only 15 of the 24 males mated. Matings were always signifcantly higher in one of the sets. Surprisingly only 7 of the 14 females laid eggs after this trial. They did after a follow up trial which may support the original hypothesis and speak against a sperm precedence strategy. However underlying mechanisms need to be determined and follow up results including the microsatellite analysis will be presented at the conference.