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ABSTRACT. The mite Varroa destructor is an ectoparasite that is considered a major pest for beekeeping with European honey bees. However, Africanized bee colonies are less threatened by this ectoparasite, because infestation levels remain low in these bees. The low reproductive ability of female mites of the Japanese biotype (J), introduced to Brazil early in the 1970s was initially considered the main factor for the lack of virulence of this parasite on Africanized bees. In other regions of the world where the Korean (K) biotype of this mite was introduced, there have been serious problems with Varroa due to the high reproductive potential of the mite. However, a significant increase in the reproductive rate of females of Varroa in Brazil has been recently demonstrated; the cause could be a change in the type of Varroa in the bee colonies. We evaluated the prevalence of haplotypes J and K in mite samples collected from the State of Santa Catarina and from the island of Fernando de Noronha in the State of Pernambuco. The analysis of the mitochondrial genome (PCR + RFLP) revealed haplotype K in all samples from Santa Catarina and haplotype J in all samples from Fernando de Noronha. The analysis of microsatellites (nuclear genome) in bees from Fernando de Noronha Varroa destrutor haplotypesshowed only the specific alleles of haplotype J, while in bees from Santa Catarina, these alleles were found in only 2.8% of the samples. The high frequency of individuals with Korean genetic material is probably to the reason for the current high reproductive capacity of the mite V. destructor recorded in Santa Catarina.

-Molecular markers are widely used in biology to address questions related to ecology, genetics and evolution. In bees, molecular studies addressing those issues have focused on Apis and Apis mellifera. Here we describe examples where molecular markers from mtDNA and microsatellite analyses were applied to stingless bees species. The data obtained, although in some cases preliminary, have already proven useful to infer hypotheses about phylogeny, population dynamics, species validity and the evolution of this group of bees. stingless bees / molecular marker / mitochondrial DNA / microsatellite / evolution / Apidae / Meliponini

ABSTRACT. The mite Varroa destructor is the main pest causing damage to apiculture worldwide. In Brazil and other parts of the world, where bees of African origin and their hybrids predominate, the bees can survive these mites without treatment. Studies have shown a correlation between the various genotypes of the mite and its fertility in different geographical regions. Information about mite genotype could be helpful in understanding the diverse effects and relationships of the mite with bees in different regions of the world. DNA analysis by RAPD technique has permitted identification of three distinct genotypes in the mite V. destructor, namely Russian, Japanese and Papua New Guinea. We found predominance of the Russian genotype in Brazil, along with other parts of South America, and in Cuba and Mexico. The Japanese genotype was exclusively found on Fernando de Noronha Island in Brazil.

The prevalence of Salmonella on surfaces, water, and broiler chicken (carcasses, parts, viscera, and spoils) taken from a poultry slaughterhouse located in the south of Brazil was studied. The automated mini-VIDAS system (a variation of the basic enzyme-linked immunosorbent assay) was used to screen for the presence of this microorganism in 615 samples, and the traditional culture method was used in 470 samples. We detected Salmonella in the following sampling points by the VIDAS Salmonella test: transport cages (16.7%), boxes (10%), scalding water (16.7%), chilled water (6.7%), carcass before evisceration (6.7%), carcass after chilling (3.3%), fresh breast (3.3%), fresh leg (10%), frozen wing (13.3%), frozen leg (13.3%), intestines (6.7%), skin of breast and leg (10%), and skin of neck (6.7%). Nevertheless, with the traditional culture method we only detected salmonellae in the following sampling points: scalding water (10%), fresh leg (6.7%), frozen wing (10%), skin of breast and leg (20%), and skin of neck (10%). Finally, 5.4% (33 of 615) of the samples analyzed by the VIDAS Salmonella system were positive, whereas the positive percentage with the traditional method was 2.6% (12 of 470). The results showed that transport cages, scalding water, frozen wing, frozen leg, and skin of breast and leg were the sampling points that demonstrated the greatest prevalence.

Different levels of infestation with the mite Varroa jacobsoni have been observed in the various Apis mellifera races. In general, bees of European races are more susceptible to the mite than African honey bees and their hybrids. In Brazil honey bee colonies are not treated against the mite, though apparently both climate and bee race influence the mite infestation. Six mixed colonies were made with Italian and Africanized honey bees. The percentage infestation by this parasite was found to be significantly lower in adult Africanized (1.69 ± 0.44) than Italian bees (2.79 ± 0.65). This ratio was similar to that found in Mexico, even though the Africanized bees tested there had not been in contact with varroa, compared to more than 20 years of the coexistence in Brazil. However, mean mite infestation in Brazil on both kinds of bees was only about a third of that found in Mexico.
Desde o contato inicial entre o ácaro Varroa jacobsoni e a abelha Apis mellifera, diferentes níveis de infestação foram verificados entre as diversas raças dessa espécie de abelhas. O presente trabalho teve como objetivo verificar o grau de infestação determinado pelo acaro Varroa jacobsoni em abelhas Apis mellifera, africanizadas e italianas puras, quando criadas numa mesma colméia. Para isso, o grau de infestação foi obtido em seis colônias de abelhas constituídas de operárias de ambas as raças. O resultado de dezesseis repetições mostrou que as abelhas africanizadas foram menos infestadas que as abelhas italianas. Esse resultado sugere que, nas condições naturais de infestação, as abelhas africanizadas são mais defensivas ao parasita Varroa jacobsoni, garantindo a essa raça de abelhas a resistência à praga varroosis

Neotropical Entomology 34(3): 381-385 (2005) The objective of the present study was to characterize restriction site variation in the mitochondrial DNA of each subspecies. Four colonies of each subspecies were sampled. One individual per colony was used for DNA extraction and further analysis through amplification of nine fragments of the mitochondrial genome and digestion with 13 restriction enzymes (PCR+RFLP). Three enzymes showed restriction pattern differences between the subspecies. Those differences will be useful to determine the maternal origin of hybrids colonies, which may occur naturally or due to colony transportation among breeders.