Colony relatedness in aggregations of Apis dorsata Fabricius (Hymenoptera, Apidae)

Abstract

Apis dorsata colonies often form dense aggregations, with over 100 colonies sometimes seen in the same tree. Reasons for these aggregations are unknown, but one reasonable hypothesis is that colonies form a related family group. Here we show that 7 adjacent colonies sampled from a single branch of a tree (near Alor Setar in northern peninsular Malaysia) containing over 120 colonies were not related as mother/daughter. Thus the notion that aggregations arise through splitting of the first-arriving colonies can be rejected.

Aggregations of unrelatedApis floreacolonies

“…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).…”

“…Nesting in aggregations is likely to be associated with at least some costs including: (i) increased potential for the transmission of parasites and pathogens between nests; (ii) local depletion of floral resources leading to nutritional competition among colonies and (iii) increased potential for detection by predators (Oldroyd et al, 2000). However, the fact that nest aggregations occur in at least 4 of the 9 extant honey bee species suggests that there are likely to be adaptive benefits of aggregation that outweigh these potential costs.…”

“…Briefly, the suggested benefits are (i) swarms might seek to join aggregations because of the potential for cooperative nest defense among colonies (Seeley et al, 1982). This seems unlikely because at least in A. dorsata, adjacent colonies rarely join defensive swarms when a colony is attacked by a mammalian or avian predator (Kastberger and Sharma, 2000); (ii) swarms might seek to join aggregations as a means to improving the mating success of offspring queens and drones (Oldroyd et al, 2000). Honey bees mate on the wing under potentially hazardous circumstances.…”

“…Honey bees mate on the wing under potentially hazardous circumstances. Thus the nearby presence of large numbers of colonies may enhance fitness by providing large numbers of unrelated males so that inbreeding is avoided and queens can mate expeditiously (Oldroyd et al, 2000); (iii) swarms may be attracted by the presence of other successful colonies, as they indicate that an area is resource rich (Oldroyd et al, 1995(Oldroyd et al, , 2000.…”

Genetic reincarnation of workers as queens in the Eastern honeybee Apis cerana

“…The original queen was not available for colony 1 as this colony lost its queen by chance. However, we had previously collected a sample of 24 worker pupae from this colony for another experiment; the genotype of the original queen was inferred from this sample (Oldroyd et al, 2000).…”