Evidence for reproductive isolation between two colour morphs of cavity nesting honey bees (Apis) in south India

Abstract

In south India there are two distinct colour morphs of cavity nesting honey bees: the yellow Plain morph and the black Hill morph which are collectively known as Apis cerana. We show that the Hill morph is associated with a widely distributed mitochondrial haplotype that is present throughout mainland populations of south east Asian A. cerana. In contrast, the Plain morph, which is apparently confined to low to moderate elevations in India and Sri Lanka, is associated with a unique mitochondrial haplotype that is not present in other cavity nesting honey bees. We further show that in a region of sympatry (Bangalore, Karnataka State) the drone mating flight times of the two colour morphs barely overlap. Combined, drone flight data and the complete separation of mitochondrial haplotypes suggest that the two morphs are reproductively isolated. The Plain morph is distinguished from the Hill morph by the first three abdominal tergites of the worker, which are completely yellow in the Plain morph, whereas in the Hill morph they are black or black with yellow patches. Although the two morphs are generally distinguishable in the field by overall colouration, microscopic examination of the first 3 abdominal tergites is preferred.

A molecular phylogeny of the genusApissuggests that the Giant Honey Bee of the Philippines,A. breviligulaMaa, and the Plains Honey Bee of southern India,A. indicaFabricius, are valid species

“…The Plains cavity‐nesting bee from Kanataka groups with mainland A. cerana , although the two are genetically quite divergent: the value of 2.1% is similar to the distance (2.2%) between the examined representatives of A. cerana and A. nigrocincta (we note that four ‘Plain’ individuals from four different colonies were sequenced; in each case the sequences were identical for all three genes). This result is consistent with a previous study (Oldroyd et al, 2006) and supports the idea that the Plain Honey Bee represents a new species.…”

“…The second taxon of interest not included in the two recent molecular phylogenies is the yellow ‘Plains’ morph of cavity‐nesting honey bees from southern India. Based on a region that spans both coding and non‐coding regions between the tRNA leu and COII genes of the mitochondria, Oldroyd et al (2006) showed that the mitochondrial haplotype carried by this morphotype is dramatically diverged from the ubiquitous ‘mainland Asia’ family of haplotypes that are carried by other A. cerana (Fabricius, 1793) across its range (Smith & Hagen, 1996). In addition, drones of the ‘Plains’ morph have an earlier mating time than drones of the black ‘Hill’ morph, which is sympatric in south India.…”

“…The ‘Hill’ morph carries the ‘mainland Asia’ (Smith & Hagen, 1996) haplotype. Combined molecular and behavioural evidence suggests reproductive isolation of the ‘Plains’ and ‘Hill’ morphs (Oldroyd et al, 2006). Thus the Plains morphotype may be a separate species from A. cerana .…”

Partial reproductive isolation between European subspecies of honey bees

“…On the other hand, the differences in time of day between honey bee subspecies when drones perform mating flights are small (Drescher 1969;Tuchashvili 1969;Rowell et al 1986) and probably not important for the reproductive isolation. There are, however, differences in this respect between two colour morphs of A. cerana (Oldroyd et al 2006). In contrast to the prezygotic barriers mentioned above, there is no information about postzygotic barriers between honey bee subspecies-the hybrids, for example the Buckfast breading line, are both viable and fertile.…”

Scientific Opinion on the risk of entry of Aethina tumida and Tropilaelaps spp. in the EU

“…Mature Tropilaelaps mites, including the original female, emerge from the brood cell along with the hatching honey bee to search for new hosts. Tropilaelaps mites actively search for and enter a new honey bee brood cell within 1.3 days (Oldroyd et al, 2006).…”