Thomas E. Rinderer

Colony defense by africanized and European honey bees.

Africanized and European honey bee (Apis mellifera) populations showed quantitative differences in colony defensive behavior. Africanized bees responded faster and in much larger numbers than European honey bees and produced 8.2 and 5.9 times as many stings during two different experiments. Times to react to alarming stimuli were negatively correlated with the number of bees responding and to the total number of stings. The number of bees responding was significantly correlated to the total number of stings only for the Africanized population.

THE AFRICANIZATION OF HONEYBEES (APIS MELLIFERA L.) OF THE YUCATAN:A STUDY OF A MASSIVE HYBRIDIZATION EVENT ACROSS TIME

Abstract Until recently, African and European subspecies of the honeybee (Apis mellifera L.) had been geographically separated for around 10,000 years. However, human‐assisted introductions have caused the mixing of large populations of African and European subspecies in South and Central America, permitting an unprecedented opportunity to study a large‐scale hybridization event using molecular analyses. We obtained reference populations from Europe, Africa, and South America and used these to provide baseline information for a microsatellite and mitochondrial analysis of the process of Africanization of the bees of the Yucatan Peninsula, Mexico. The genetic structure of the Yucatecan population has changed dramatically over time. The pre‐Africanized Yucatecan population (1985) comprised bees that were most similar to samples from southeastern Europe and northern and western Europe. Three years after the arrival of Africanized bees (1989), substantial paternal gene flow had occurred from feral Africanized drones into the resident European population, but maternal gene flow from the invading Africanized population into the local population was negligible. However by 1998, there was a radical shift with both African nuclear alleles (65%) and African‐derived mitochondria (61%) dominating the genomes of domestic colonies. We suggest that although European mitochondria may eventually be driven to extinction in the feral population, stable introgression of European nuclear alleles has occurred.

DNA Evidence of the Origin of Varroa jacobsoni Oudemans in the Americas

Randomly amplified polymorphic DNA (RAPD) was used to examine possible origin of Varroa jacobsoni Oudemans in the Americas. Among 64 primers screened, 2 primers provided variation which was informative for this study. All V. jacobsoni collected from the United States had the same banding pattern to that of mites collected from Russia, Morocco, Germany, Italy, Spain, and Portugal (Russian pattern). This banding pattern was different from the pattern found for mites collected from Japan, Brazil, and Puerto Rico (Japanese pattern). The Japanese pattern lacked a 766-bp band found in the Russian pattern (OPE-07). With primer OPP-03, the Russian pattern had a distinct band at 442 bp not found in the Japanese pattern. Two bands located at 675 and 412 bp were specific to the Japanese pattern. These results suggest that the V. jacobsoni of the United States is probably predominantly Russian in origin (via Europe), while the V. jacobsoni of Brazil and Puerto Rico are probably predominantly Japanese in origin.

A Model of Honeybee Defensive Behaviour

SummaryA model of defensive behaviour by an individual honeybee (Apis mellifera) is presented. The behavioural sequence involves four basic steps: alerting, activating, attracting and culminating. The model accommodates both genetic and environmental variation.

Diet-selection ecology of tropically and temperately adapted honey bees

Abstract Colonies of tropically adapted (Africanized) honey bees had greater numbers and higher percentages of pollen foragers than did temperately adapted (European) honey bees. European colonies had greater overall foraging activity. The number of pollen gatherers in Africanized nests was greater throughout the daily foraging cycle, and was especially high early in the morning when pollen was most abundant. Africanized colonies fielded more pollen collectors even when levels of stimuli which are known to regulate pollen foraging were altered experimentally. Collectively, the foraging patterns resulted in larger stores of pollen in Africanized honey bee nests, while European bee nests typically had larger honey and nectar caches. In mixed nests composed of equal portions of adults of each bee ecotype, foraging patterns were similar for ecotypes within a colony. The behavioural root of differences in resource gathering appears to lie with the nurse bees and foragers of a colony, not with the brood type. Diet selection differences are probably influenced strongly by the climatological constraints which regulate the survival and reproductive capacities of these two bee ecotypes.

Analysis of Africanized honey bee mitochondrial DNA reveals further diversity of origin

Nos ultimos 40 anos, abelhas africanizadas se espalharam a partir do Brasil e agora ocupam a maioria das areas habitaveis pela especie Apis mellifera, da Argentina ao sudoeste dos Estados Unidos. Acredita-se que a fonte genetica primaria das abelhas africanizadas seja a subespecie subsaariana de abelha A. m. scutellata. Marcadores mitocondriais comuns em A. m. scutellata tem sido usados para classificar abelhas africanizadas em estudos de fisiologia e genetica de populacao. A avaliacao de haplotipos mitocondriais compostos em abelhas africanizadas, usando 3 enzimas de restricao e um polimorfismo de comprimento no espacador intergenico COI-COII, evidenciou uma heranca mitocondrial mais diversa. Mais de 25% do mtDNA africano encontrado em populacoes africanizadas na Argentina sao derivados de fontes nao relacionadas a A. m. scutellata.

Honey bees dance with their super-sister

Abstract Four colonies of honey bees, Apis mellifera , each composed of two subfamilies were separately placed in a screen cage. Bees of each subfamily were found at different frequencies on a pollen feeder, a sucrose feeder and on the roof of the cage, indicating subfamilial genetic variance for foraging preferences. The colonies were then placed in observation hives, and communication dances were observed. The type (pollen or no pollen) and subfamily of dancers and the subfamily of recruits were recorded. Subfamilial variance for nectar or pollen preference and propensity to dance were observed in every case. There was a strong tendency for recruits to follow dances performed by a member of their own subfamily, indicating subfamily recognition. However, at least some of this positive assortment was due to a complex interaction of genotypic differences among subfamilies in their foraging preferences and tendencies to dance.

Measuring the Heritability of Characters of Honeybees

SummaryParent-offspring regression, intra-sire regression of offspring on dam, and sibling analysis, were examined for their usefulness in estimating heritabilities of characters of the honeybee (Apismellifera). These examinations indicate the allowances required for sibling workers with a coefficient of relationship of 0·75, and provide an approach to evaluate the usefulness of selecting breeding queens on the basis of their response, although the aim is improvement of response in worker progeny. Consideration is given to the consequences of a character being an attribute of individual workers, of groups of workers, or of queens.

Differential Pollen Collection by Africanized and European Honeybees in Venezuela

SummaryA study of pollen collection by Africanized and European honeybees was conducted in Venezuela. Among the Africanized honeybees a larger proportion of the foraging force foraged for pollen, thus collecting significantly larger quantities of pollen. The larger pollen supply would provide the protein necessary to support increased brood production, thereby increasing the opportunities for Africanized honeybee colonies to cast multiple swarms.

Honey bee hoarding behaviour: Effects of previous stimulation by empty comb

Abstract Hoarding experiments were performed utilizing the transfer of honey bees (Apis mellifera) from cages with large or small amounts of empty honeycomb to cages with equal, greater, or lesser amounts. Results confirmed that empty comb stimulates hoarding. Furthermore, bees that were transferred from a small to a greater amount of comb hoarded significantly more than control bees, indicating that stimulus deprivation followed by stimulus enrichment increases the strength of the hoarding response.