Aggregations of Unrelated Apis Florea Colonies Wandee Wattanachaiyingcharoen, Siriwat Wongsiri, Benjamin P
Total Page:16
File Type:pdf, Size:1020Kb
Aggregations of unrelated Apis florea colonies Wandee Wattanachaiyingcharoen, Siriwat Wongsiri, Benjamin P. Oldroyd To cite this version: Wandee Wattanachaiyingcharoen, Siriwat Wongsiri, Benjamin P. Oldroyd. Aggregations of unrelated Apis florea colonies. Apidologie, Springer Verlag, 2008, 39 (5), pp.531-536. hal-00891920 HAL Id: hal-00891920 https://hal.archives-ouvertes.fr/hal-00891920 Submitted on 1 Jan 2008 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Apidologie 39 (2008) 531–536 Available online at: c INRA/DIB-AGIB/ EDP Sciences, 2008 www.apidologie.org DOI: 10.1051/apido:2008045 Original article Aggregations of unrelated Apis florea colonies* Wandee Wattanachaiyingcharoen1, Siriwat Wongsiri2,BenjaminP.Oldroyd3 1 Department of Biology, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand 2 Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10320, Thailand 3 Behaviour and Genetics of Social Insects Lab, School of Biological Sciences A12, University of Sydney, NSW 2006, Australia Received 5 July 2007 – Revised 25 March 2008 – Accepted 13 May 2008 Abstract – Intensive surveys of an area of woodland in Phitsanulok province, Thailand, revealed 15 colonies of Apis florea. The colonies had a highly aggregated spatial distribution (Standardized Morisita’s Index of Dispersion = 0.59). Microsatellite analysis based on 5 loci showed that no colonies were related as mother- daughter, suggesting that unrelated colonies tend to nest near existing colonies. aggregation / Apis florea / Thailand /dwarf honey bee / colony relatedness 1. INTRODUCTION well over 100 colonies sharing a single large tree or cliff face (Underwood, 1986, 1990; Animals and plants often have a clumped Oldroyd et al., 2000; Paar et al., 2004; Ol- spatial distribution, which is usually assumed droyd and Wongsiri, 2006). A. mellifera L. to arise from heterogeneity in the environ- forms lose aggregations, in which up to 10 ment, with the distribution tracking favourable colonies may be found in an area as small as sites (Forman and Gordon, 1987). Even when 1 hectare (Oldroyd et al., 1995; McNally and no environmental heterogeneity is discernable, Schneider, 1996; Baum et al., 2005). The two it is often assumed that clumped distribu- dwarf honey bee species A. florea Fabricius tions arise from cryptic environmental hetero- and A. andreniformis Smith also form loose geneity. More recently, it has been recognized aggregations of nests (Rinderer et al., 2002). that spatial patterns can arise through self- This is despite the fact that A. florea and A. organized interactions (Ball, 1999), for exam- andreniformis are both open-nesting species, ple between density-dependent predation and and so a heterogeneous distribution of suitable population growth (Maron and Harison, 1997; nest sites seems an unlikely cause of nest ag- Vandermeer et al., 2008) or simple attrac- gregations in the dwarf bees (Koeniger, 1976). tion between individuals of the same species Baum et al. (2005) suggested that patchy dis- (Sumpter, 2006). tributions of suitable nesting cavities may con- Four species of honey bee are often found tribute to the phenomenon of nest aggregation to nest in aggregations. The giant honey bees, in A. mellifera. Nonetheless, aggregations of A. dorsata Fabricius and A. laboriosa Smith, A. mellifera have also been observed in envi- are the most extreme in this regard, often ronments where the number of available cavi- forming massive aggregations of nests, with ties is extremely large (Oldroyd et al., 1995). Corresponding author: The adaptive significance (if any) of nest W. Wattanachaiyingcharoen, aggregation in Apis remains unclear. Nesting [email protected] in aggregations is likely to be associated with * Manuscript editor: Walter S. Sheppard at least some costs including: (i) increased Article published by EDP Sciences and available at http://www.apidologie.org or http://dx.doi.org/10.1051/apido:2008045 532 W. Wattanachaiyingcharoen et al. potential for the transmission of parasites and 1974; Sheikh and Chetry, 2000; Oldroyd and pathogens between nests; (ii) local depletion Wongsiri, 2006). Little is known about repro- of floral resources leading to nutritional com- ductive swarming in this species. Akratanakul petition among colonies and (iii) increased (1977) observed one reproductive swarm de- potential for detection by predators (Oldroyd part the parent nest and settle about 20 m away, et al., 2000). However, the fact that nest ag- but did not record whether this was a tempo- gregations occur in at least 4 of the 9 ex- rary cluster or if the swarm subsequently left tant honey bee species suggests that there are to build a comb elsewhere. likely to be adaptive benefits of aggregation In this study, we examined the natural dis- that outweigh these potential costs. Briefly, tribution of and relatedness of nests of A. flo- the suggested benefits are (i) swarms might rea, in a heavily forested area of Phitsanulok seek to join aggregations because of the po- province in lower northern Thailand. The area tential for cooperative nest defense among studied was homogenous, and there was no colonies (Seeley et al., 1982). This seems un- pesticide usage, so environmental factors are likely because at least in A. dorsata, adjacent unlikely to have cause aggregation. In this re- colonies rarely join defensive swarms when a spect our study contrasts with that of Rinderer colony is attacked by a mammalian or avian et al. (2002) who found evidence for aggrega- predator (Kastberger and Sharma, 2000); (ii) tion of nests of the dwarf honey bees in an area swarms might seek to join aggregations as where horticultural plantings created a hetero- a means to improving the mating success of geneous environment. We also provide the first offspring queens and drones (Oldroyd et al., investigation of the relatedness of nests within 2000). Honey bees mate on the wing under and between aggregations of A. florea using potentially hazardous circumstances. Thus the microsatellite genetic markers. Thus we were nearby presence of large numbers of colonies able to determine if clusters arise via short- may enhance fitness by providing large num- distance dispersal of reproductive swarms. bers of unrelated males so that inbreeding is avoided and queens can mate expeditiously (Oldroyd et al., 2000); (iii) swarms may be 2. MATERIALS AND METHODS attracted by the presence of other successful colonies, as they indicate that an area is re- The survey was conducted in an area of Muang source rich (Oldroyd et al., 1995, 2000). District, Phitsanulok province, Thailand. The sur- There may also be non-adaptive causes of veyed area comprised numerous shrubs and trees nest aggregations including: (i) a heteroge- and some buildings. We surveyed the area in- nous distribution of suitable nesting sites or tensively for a period of 4 months from June- hazards like insecticide application; (ii) en- September 2004. This period is during the rainy sea- dogenous cluster formation caused by interac- son when A. florea populations are low. Each tree tions between factors unrelated to the physical and other possible nest sites were observed by at environment (Czárán and Bartha, 1992; Ball, least two people at a time. 1999); (iii) migrating swarms tending to ag- When nests were located, their precise location was determined with the aid of a Global Positioning gregate at the same place because they follow the same behavioural rules during migration System receiver (Garmin , Garmin Taiwan). The (Oldroyd and Wongsiri, 2006). positions of nest were then mapped using the Ar- cView GIS 3.2 program (ESRI). We overlaid the The red dwarf honey bee, Apis florea, colony locations on this map with quadrats of size of south east Asia and India builds a sin- 400 × 400 m, and used the number of colonies gle comb suspended from a twig or small per quadrat to calculate the standardized Morisita’s branch, within which it stores honey and index of dispersion (Krebs, 1989). This index pro- pollen and raises brood (Wongsiri et al., 1997; vides one of the best estimates of biological disper- Oldroyd and Wongsiri, 2006). The species is sion because it is independent of density and popu- highly migratory, with colonies moving into lation size (Krebs, 1989). areas where floral resources are abundant, From each colony, we collected 40 adult work- and leaving when resources decline (Pandey, ers. DNA was extracted from the thorax of each bee Aggregations of unrelated Apis florea colonies 533 using Chelex resin (Walsh et al., 1991). Diluted allele at all loci. We cannot exclude the possi- DNAs (1:4) were amplified in a thermocycler using bility that some colonies were headed by half- microsatellite loci isolated from A. mellifera (A8, sister queens, but we did not analyze sufficient A76, A88, A107), and Bombus terrestris (B124) loci to test this hypothesis statistically. (Estoup et al., 1993), but known to amplify cleanly in A. florea (Palmer and Oldroyd, 2001). PCR prod- ucts were then electrophoresed in 12% denaturing 4. DISCUSSION polyacrylamide gels. After electrophoresis, the am- plified products were visualized using silver stain- ing (Bassam et al., 1991). Our results show that the previously- We determined the expected heterozygosity for reported tendency for A. florea nests to have all loci from the observed allele frequencies. At a clumped spatial distribution (Rinderer et al., each locus for each colony, we inferred the geno- 2002) did not arise as a consequence of het- type of the queen heading the colony from the erogeneity in suitable nesting sites. Our study, distribution of worker alleles (Estoup et al., 1994; conducted in habitat with a uniform distribu- Oldroyd et al., 1996).