Partial seasonal isolation of African and European-derived Apis mellifera (Hymenoptera : Apidae) drones at congregation areas from subtropical Mexico

The genetic interactions between European and African-derived honey bees in the Neotropics are unclear. To study the abundance of males of each type, two apiaries with colonies of African-derived honey bee and European honey bee origin were established in the surroundings of one drone congregation a rea. The frequencies of African-derived honey anti European honey Lee males in the mating area were studied by taking samples of drones at the drone c ongregation area twice a month for 5 mo. Drones from each type of colony we re identified by the use of two allozyme polymorphic systems: malate dehydr ogenase (Mdh), hexokinase (Hk), and by haplotype using the EcoRI site of th e mitochondrial DNA. The results of a Fisher exact test show ed that, altho ugh Mdh alleles had similar frequencies across the time of study (P = 0.095 ), the frequency of Hk alleles and haplotypes in drones varied between mont hs (P = 0.0001). Early in March. the frequencies of African-derived honey L ee-typical alleles were significantly higher compared with European honey b ee-typical alleles. However, at the end of the season of drone production i n July, European honey bee-typical alleles were significantly more frequent in drones than those of the African-derived honey bee type. The results mi rror the findings of all early peak of drone brood production reported for African-derived honey Lee colonies compared with a peak later in the year i n European honey bee ones. It is concluded that the seasonal frequencies of African-derived honey bee and European honey bee drones in the mating area s are not static.. They vary in accordance with the different peaks of male production in their respective colonies. This behavior may act as a partia l genetic barrier between Lee types. The implications of these findings wit h respect to current levels of Africanization in this region of Mexico and for queen rearing in Africanized areas are discussed.