Author
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Villa, Joseph |
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Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/1/2003 Publication Date: 1/1/2004 Citation: Villa, J.D. 2004. Swarming behavior of honey bees (hymenoptera: apidae)in southeastern Louisiana. Annals of the Entomological Society of America 97(1):111-116. Interpretive Summary: Until recent years, honey bees introduced since colonial days from Europe had been very successful in occupying many regions of North America unassisted by humans. Studies were conducted over the past nine years in southeastern Louisiana to clarify what factors account for this success, and to observe changes brought about by the recent arrival of other non-native organisms: Africanized bees and parasitic mites. Observations show that European bees in this area produce new colonies (swarms) in the Spring (March to June). A swarm moves to a temporary location from which workers search for a new site to occupy. After about two days, the whole swarm moves to a permanent location. Swarms move in many directions and to distances up to about 6 miles. They prefer to occupy cavities with a volume of about 7 gallons over smaller ones. The initial number of workers in a swarm, or the height of the occupied cavity does not influence the survival of swarms, but the appearance of parasitic varroa mites in 1992 has greatly reduced survival times. Currently, only colonies in which the ubiquitous mites are controlled by beekeepers will survive and reproduce. Most of the swarms currently seen in an area likely come from beekeepers' colonies, and will eventually die once the parasite load overwhelms the colony. It is likely that the same is occurring to Africanized bees, and therefore they have not been able to occupy new areas in the southeastern United States. Technical Abstract: Reproductive swarming phenology, swarm sizes and cavity selection were studied in a European-derived population of Apis mellifera L. in southeastern Louisiana before and immediately after the initial detection in 1992 of Varroa destructor Anderson & Trueman (Acari: Varroidae). Frequency of swarms was highest between early April and early May in each of six years. Swarm weight averaged 1.42 kg, ranged from 0.17 to 4.30 kg, and did not change significantly the year after the detection of V. destructor. Swarms spent an average of about 20 daylight hours scouting for a new nest-site from a temporary location, and moved more frequently to cavities of 30 l than to those of 13 l volume. Swarms were random in direction of movement. Dance tempos at time of swarm departure indicated movement to cavities at distances from 200 m to around 10 km. The genetic composition of this honey bee population is likely to change after natural and artificial selection for resistance to new parasites such as V. destructor and Aethina tumida Murray (Coleoptera: Nitidulidae), and as Africanized bees expand their range. Swarming characteristics are also likely to change both from direct effects of parasites on colony reproduction, and by changes towards bee populations with differing life histories. |
