Africanized Honeybees

African honeybees, introduced into Brazil in 1956 in an effort to improve honey production, are the subject of Mark Winston's book, ``Killer Bees - the Africanized Honeybee in the Americas''. Winston shows how the characteristics that make these bees difficult to deal with are exactly the characteristics that have made them successful in the tropics of Africa and the Americas.

Compared to European honeybees, Africanized bees put more of their energy into reproduction, concentrating more on pollen gathering than honey making. Their smaller nests are less attractive to the numerous predators in the tropics. In the event the colony decides relocate (abscond) because of disturbance, it has less to lose. In addition, Africanized honeybees are more sensitive to poor pollen and nectar conditions and tend to abscond more often in search of better areas. This is an advantage in the tropics where the nectars tend to be more watery and the flowers are more scattered. A high proportion of the nests are outside of cavities, making them easier to cool. Around the hive they appear more active and agitated. The time between egg and adult worker is about 18.5 days, compared to about 21 days for the European honeybee. Workers are smaller and lighter. These bees have a shorter fuse than their European counterparts and produce a greater amount of alarm pheromone. On an individual basis, they inject less toxin. The colonies have a higher swarming (colony reproduction or splitting) rate - a consequence of their faster life cycle and preference for smaller nests.

Because of the smaller colony size and lack of honey storage, it is expected that colonies of Africanized bees will have difficulty surviving the harsh northern winters and that a transition zone will form across which the Aficanized honeybees will give way to the European honeybees. Certainly excursions north of this zone are possible under suitable conditions, particularly during the warmer weather. Since the European and Africanized honeybees are the same species, some interbreeding can be expected in this region. Where Africanized honeybees are established the European colonies tend to become Africanized because their males are less successful breeders. The location of the transition zone is not yet known and may change due to interbreeding. It will certainly change if the Africanized bees modify their behavior in response to the different environmental influences.

Based on experiences in South and Central America, it is expected that the density of feral colonies will be low for an initial period while the bees are colonizing an area. After that period, perhaps as much as 1 or 2 years, the population will rise quickly. In colonized areas, the public can expect to encounter more foraging bees and more swarms (relocating colonies). Foraging bees are usually tolerant although bad weather may make them less so. Swarming bees are generally docile partly because they have limited energy reserves and their main concern is a new home site. In this search they can travel over 80 miles. The public can also expect to encounter more feral colonies whose behavior, unfortunately, is less predictable.

We have a new social insect in North America, one which will certainly affect our outdoor activities. Agriculture will be affected since many crops are bee pollinated. Currently, migratory beekeepers move colonies all over the country providing pollination services because the vast fields of crops are too large to be pollinated by local insects. During the winter months, these colonies are normally kept in the south, a region that promises to support Africanized bees. The potential impact is significant ranging from crop losses due to inadequate pollination, reduced honey and beeswax production, quarantines and/or restrictions on migratory beekeeping, and the elimination of hobby beekeeping.

Borrow the book from your local library. It's worth reading. In the meantime, develop your awareness of honeybees and their habits. (Don't forget to listen.)

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Ron Lyons (volunteer 1990-1999)
Chula Vista Nature Center, 1000 Gunpowder Point Drive, Chula Vista, CA 91910-1201