Vol. 12, Issue 3 (2023)

Author(s):
Muneer Ahmad, Shafeeq Hakeem, Sushil Kumar, Zewar Husain and Nadeem Dar

Abstract:
It has often been said that bees are responsible for one out of every three bites of food we eat. Most crops grown for their fruits (including vegetables such as squash, cucumber, tomato and eggplant), nuts, seeds, fiber (such as cotton), and hay (alfalfa grown to feed livestock), require pollination by insects. Pollinating insects also play a critical role in maintaining natural plant communities and ensuring production of seeds in most flowering plants. Pollination is the transfer of pollen from the male parts of a flower to the female parts of a flower of the same species, which results in fertilization of plant ovaries and the production of seeds. The main insect pollinators, by far, are bees, and while European honey bees are the best known and widely managed pollinators, there are also hundreds of other species of bees, mostly solitary ground nesting species, that contribute some level of pollination services to crops and are very important in natural plant communities. Hygienic behavior of honeybees involves inspection, uncapping and removal of diseased and dead brood from the colony. The objective of this review is to study the activities involved in hygienic behavior of individually tagged bees from selected hygienic (H) and non-hygienic (NH) colonies in the presence of chalk brood infected brood (Ascosphaera apis) or pin-killed brood or varroa infected brood. The hygienic behavior of honey bee workers contributes to the social immunity of colonies. The ability of workers to detect and remove unhealthy or dead brood prevents the transmission of brood diseases inside the colony. Over the last five decades, this trait has been extensively studied and improved in several research and breeding programs. Given the strong interest for hygienic behavior, we here review the costs and benefits associated with this trait, extending preceding reviews on this subject from the late 1990s. Since the 1990s, there have been no major new insights on the efficiency of this behavior against American foulbrood and chalk brood. However, the number of publications on hygienic behavior against the mite Varroa destructor has considerably increased, fueling the debate regarding the efficiency of hygienic behavior against this parasite. Breeding programs have shown that selection for a specific trait might also impact other traits. Thus, we also review the cost of trade-offs between hygienic behavior and other economically important traits for bee breeders. Overall, the benefits of hygienic behavior seem to largely outweigh its costs for both colonies and bee breeders. Hygienic behavior is a heritable genetic trait, which is commonly taken into account in A. Mellifera breeding programs in order to improve the vitality of the stocks. Such programs have been running for several years and the hygienic abilities and disease resistance of breeding A. mellifera colonies have largely been strengthened. The assay consisting in monitoring the removal of freeze-killed brood from a comb section has been acknowledged as the most conservative and reliable screening procedure to quantify the hygienic behavior of a colony.