Geographical distribution of the giant honey bee Apis laboriosa Smith, 1871 (Hymenoptera, Apidae).

Worldwide pollinator declines have dramatically increased our need to survey and monitor pollinator distributions and abundances. The giant honey bee, Apis laboriosa, is one of the important pollinators at higher altitudes of the Himalayas. This species has a restricted distribution along the Himalayas and neighbouring mountain ranges of Asia. Previous assessments of its distribution, published more than 20 years ago, were based on museum specimens. Since then, 244 additional localities have been revealed through field trips by the authors, publications, and websites. We present a revised distribution for A. laboriosa that better defines its range and extends it eastward to the mountains of northern Vietnam, southward along the Arakan Mountains to west-central Myanmar, into the Shillong Hills of Meghalaya, India, and northwestward in Uttarakhand, India. This species is generally found at elevations between 1000-3000 m a.s.l.. In northeastern India A. laboriosa colonies occur during summer at sites as low as 850 m a.s.l. and some lower elevation colonies maintain their nests throughout the winter. Finally, we report three regions in Arunachal Pradesh, India, and nine locations in northern Vietnam, where we observed workers of A. laboriosa and A. dorsata foraging sympatrically; their co-occurrence supports the species status of Apis laboriosa.

Influence of pollen diet in spring on development of honey bee (Hymenoptera: Apidae) colonies.

The effects of changes in spring pollen diet on the development of honey bee, Apis mellifera L. (Hymenoptera: Apidae), colonies were examined in a 3-yr study (2002-2004). Pollen-supplemented and pollen-limited conditions were created in colonies every spring, and brood rearing and honey yields were subsequently monitored throughout the summer. In all 3 yr, colonies that were supplemented with pollen or a pollen substitute in the spring started rearing brood earlier than colonies in other treatment groups and produced the most workers by late April or early May. In 2002, these initial differences were reflected by a two-fold increase in annual honey yields by September for colonies that were pollen-supplemented during the spring compared with pollen-limited colonies. In 2003 and 2004, differences between treatment groups in the cumulative number of workers produced by colonies disappeared by midsummer, and all colonies had similar annual honey yields (exception: in one year, productivity was low for colonies supplemented with pollen before wintering). Discrepancies between years coincided with differences in spring weather conditions. Colonies supplemented with pollen or a substitute during the spring performed similarly in all respects. These results indicate that an investment in supplementing the pollen diet of colonies would be returned for situations in which large spring populations are important, but long-term improvement in honey yields may only result when spring foraging is severely reduced by inclement weather. Beekeepers should weigh this information against the nutritional deficiencies that are frequently generated in colonies by the stresses of commercial management.

Resistance to Acarapis woodi by honey bees (Hymenoptera: Apidae): divergent selection and evaluation of selection progress.

Two generations of honey bees, Apis mellifera L., selected for resistance to tracheal mites, Acarapis woodi (Rennie), were produced from a foundation stock. The mite resistant lines had significantly low mite abundances and prevalences in each selected generation. The high mite-resistant lines of the first selected generation showed resistance equal to that of bees that had undergone natural selection from tracheal mite infestations for 3 yr in New York. Additionally, the high mite-resistant lines of the second selected generation and Buckfast bees had significantly lower mite abundances and prevalences than honey bees from control colonies which had never been exposed to tracheal mite infestation in Ontario. These results corroborate studies that have shown that honey bees possess genetic components for tracheal mite resistance that can be readily enhanced in a breeding program. The two methods used for evaluating relative resistance of honey bees to tracheal mites, a short-term bioassay and evaluation in field colonies, were positively correlated (rs = 0.64, P < 0.001).

The role of cuticular compounds in the resistance of honey bees (Apis mellifera) to tracheal mites (Acarapis woodi).

This study examined the migration of tracheal mites (Acarapis woodi) into honey bees (Apis mellifera) from different colonies and the relative attraction of mites to hexane extracts from the external body surfaces of young bees. Relative resistance of bees from different colonies initially was assessed with a field bioassay that involved tagging newly emerged bees, pooling them in heavily mite-infested colonies, retrieving them 7 days later, and examining them for tracheal mite prevalence and abundance. For those colonies identified as most resistant and least resistant, cuticular chemicals were extracted in hexane from frozen, newly emerged worker bees. These extracts were presented to individual tracheal mites in pairwise fashion in a laboratory bioassay. The results demonstrated that mites prefer extracts of bees from some colonies more than others, however, no consistent differences were demonstrated. Our inability to predict mite responses to extracts based on our initial assessment of relative resistance indicates that other mechanisms of resistance influence mite success in colonizing new host bees.

Application of a modified selection index for honey bees (Hymenoptera: Apidae).

Nine different genetic families of honey bees (Apis mellifera L.) were compared using summed z-scores (phenotypic values) and a modified selection index (Imod). Imod values incorporated both the phenotypic scores of the different traits and the economic weightings of these traits, as determined by a survey of commercial Ontario beekeepers. Largely because of the high weight all beekeepers place on honey production, a distinct difference between line rankings based on phenotypic scores and Imod scores was apparent, thereby emphasizing the need to properly weight the traits being evaluated to select bee stocks most valuable for beekeepers. Furthermore, when beekeepers who made >10% of their income from queen and nucleus colony sales assigned relative values to the traits used in the Imod calculations, the results differed from those based on weightings assigned by honey producers. Our results underscore the difficulties the North American beekeeping industry must overcome to devise effective methods of evaluating colonies for breeding purposes.