APICULTURE AND SOCIAL INSECTS Efficacy of Modified Hive Entrances and a Bottom Screen Device for Controlling Aethina tumida (Coleoptera: Nitidulidae) Infestations in Apis mellifera (Hymenoptera: Apidae) Colonies

This studywasdesigned to testwhetherhive entrances reducedwithpolyvinyl chloride pipe reduce the ingress of Aethina tumida Murray into Apis mellifera L. colonies and whether screen-mesh bottom boards alleviate side effects associated with restricted entrances. Forty-eight colonies distributed equally between two locations each received one of six experimental treatments: 1) conventional solidbottomboard andopenentrance, 2) ventilatedbottomboard andopenentrance, 3) conventional bottom and 1.9-cm-i.d. pipe entrance, 4) conventional bottom and 3.8-cm pipe entrance, 5) screen bottom and 1.9-cmpipe entrance, and 6) screen bottom and 3.8-cmpipe entrance. Resultswere inconsistent between apiaries. In apiary 1, colonieswith 3.8-cmpipe entrances had fewer A. tumida than colonies with open entrances, but this beneÞt was not apparent in apiary 2. Pipe entrances tended to reduce colony and brood production in both apiaries, and these losses were only partly mitigated with the addition of screened bottom boards. Pipe entrances had no measurable liability concerning colony thermoregulation. There were signiÞcantly fewer frames of adult A. mellifera in colonies with 3.8or 1.9-cm pipe entrances compared with open entrances but more in colonies with screens. There were more frames of pollen in colonies with open or 3.8-cm pipe entrances than 1.9-cmentrances.We conclude that the efÞcacy of reduced hive entrances in reducing ingress of A. tumida remains uncertain due to observed differences between apiaries. Furthermore, there were side effects associated with restricted entrances that could be only partly mitigated with screened bottom boards.