Oldroyd and Wongsiri argue for nine species in three sub-genera: dwarf and giant open-nesting bees and cavity-nesting bees. Bees evolved from wasps around 130 million years ago, honey bees probably emerged around 35-40 million years ago, and modern species around 5-10 million years ago. The phylogenetic relationship of honey bees to orchid bees, bumble bees, and stingless bees isn't certain, but key innovations in their evolution included pollen baskets, nest thermoregulation, colony reproduction by swarming, queen/worker dimorphism, and extreme polyandry. Their speciation and biogeography have only partly been determined by sea level changes and island formation in Southeast Asia.
Dance communication has been intensely studied in Apis mellifera, but evidence from the other honey bees helps illuminate its origins and development. Dancing appears to have moved from the horizontal top of the nest (as in dwarf bees) to the vertical plane, along with increasing use of sound by dancing bees. The species also vary in foraging habits, possibly as a result of competitive displacement where they are sympatric.
Honey bees reproduce by swarming, and colonies can also abscond and migrate — up to 100 km in the giant honey bee Apis dorsata! Barriers to interspecific hybrids include mating times, the location of drone congregation areas, and anatomical barriers to copulation. There are reproductive conflicts between individuals in the colony, but worker sterility is enforced by worker policing, with queen polyandry making workers more related to their sisters than their nieces. Various explanations have been mooted for extreme polyandry; Oldroyd and Wongsiri emphasise disease resistance and other benefits of genetic diversity.
Cavity nesting species can devote more resources to growth, rather than nest thermoregulation and defense, but are constrained by shortages of suitable cavities. Dwarf bees attempt concealment of the nest and are more likely to abscond when threatened, while giant bees attack aggressively. The most significant parasites of honey bees are mesostigmatan mites, but bacteria and viruses are also a problem, and they are subject to predation by numerous other insects and vertebrates.
The final chapters cover interactions with humans. Hunting (largely of the open-nesting species) and bee-keeping have long histories in Asia, and bees are of broad social and religious importance, most notably in Hinduism and Buddhism. A. mellifera hives are easier to handle and have the highest yields, so it is the species of choice for commercial bee-keepers, but A. cerana hives are cheaper to install and maintain. Turning to conservation, Oldroyd and Wongsiri consider the importance of bee pollination, both for agriculture and for wild plants, and the ecological importance of bees as keystone species, as well as the threats they face (with some rough modelling of hunting sustainability).
The only disappointing feature of Asian Honey Bees is its physical quality, with grainy halftones and cheap paper, rather than the archival paper expected in a university press hardcover at this price. On the other hand, it has been properly proofed and edited — unfortunately not something that can be taken for granted these days — and has clear and effective diagrams.
Note: the paper in Asian Honey Bees is apparently recycled, but acid free.