Genetic Structure of an Apis dorsata Population: The Significance of Migration and Colony Aggregation

Abstract

Eight microsatellite loci were used to investigate the genetic structure of the giant honeybee (Apis dorsata) population in northeast India. This species migrates seasonally between summer and winter nesting sites, and queens appear to return to their previously occupied site. Furthermore, there is a strong tendency for colonies of this species to aggregate at perennially utilized nesting sites that may be shared by more than 150 colonies. These behavioral features suggest that colonies within aggregations should be more related than random colonies, but that the long-distance migration could act to minimize genetic differentiation both between geographical areas and within aggregations. Our genetic study supports these conjectures arising from natural history. A. dorsata aggregations are comprised of colonies that share more alleles than expected by chance. Although queens heading neighboring colonies are not close relatives, fixation indices show significant genetic differentiation among aggregation sites. However, there appears to be sufficient gene flow among aggregations to prevent high degrees of relatedness developing between colonies within aggregations. The results also suggest that there is significant population structuring between geographical regions, although the level of structuring caused by aggregation exceeds the differentiation attributable to geographic region.

Aggregations of unrelatedApis floreacolonies

“…Our study also shows that like A. dorsata (Oldroyd et al, 2000;Paar et al, 2004) and A. mellifera (Oldroyd et al, 1995) aggregations of A. florea do not arise from the clustering of daughter colonies around a single founding colony. No colonies in our study were related as mother-daughter, for no pairs of inferred queen genotypes shared one allele at all loci studied.…”

“…The giant honey bees, A. dorsata Fabricius and A. laboriosa Smith, are the most extreme in this regard, often forming massive aggregations of nests, with Corresponding author: W. Wattanachaiyingcharoen, wandee_w@hotmail.com * Manuscript editor: Walter S. Sheppard well over 100 colonies sharing a single large tree or cliff face (Underwood, 1986(Underwood, , 1990Oldroyd et al, 2000;Paar et al, 2004;Oldroyd and Wongsiri, 2006). A. mellifera L. forms lose aggregations, in which up to 10 colonies may be found in an area as small as 1 hectare (Oldroyd et al, 1995;McNally and Schneider, 1996;Baum et al, 2005).…”

Conservation of Asian honey bees

“…A. dorsata colonies are highly philopatric, often migrating over large distances, but returning to the same nesting site every year (Butani, 1950;Koeniger and Koeniger, 1980;Underwood, 1990;Dyer and Seeley, 1994;Kahona et al, 1999;Neumann et al, 2000;Paar et al, 2000;Sheikh and Chetry, 2000;Thapa et al, 2000;Itioka et al, 2001;Paar et al, 2004). Moreover, A. dorsata tend to nest in large aggregations, sometimes with more than 100 colonies on a single tree Paar et al, 2004).…”

“…We do not understand why particular trees are used year after year as nest sites Oldroyd and Wongsiri, 2006), but it may be assumed that these trees are of considerable importance to the welfare of a population (Paar et al, 2004). Anecdotal discussions with students at the Indian Institute of Science in Bangalore suggested that when a major bee tree is felled to make way for a building or other structure, the colonies attempt to build their nests on the structure.…”

Molecular markers as a tool for population and evolutionary studies of stingless bees

“…In Apis mellifera and Apis cerana, population studies have been developed using both mtDNA and microsatellite analysis and have increased our comprehension about subspecies population dynamics, biogeography, introgression, and evolution (Franck et al, 1998(Franck et al, , 2000aSegura, 2000;Sheppard and Smith, 2000;De la Rúa et al, 2001Paar et al, 2004;Sušnik et al, 2004). Similarly, morphometric analysis combined with molecular data has been applied to study intogression in honey bees (Meixner et al, 1993(Meixner et al, , 2000.…”