Since its first contact with Apis mellifera, the population dynamics of the parasitic mite Varroa destructor varies from one region to another. In many regions of the world, apiculture has come to depend on the use of acaricides, because of the extensive damage caused by varroa to bee colonies. At present, the mite is considered to contribute to the recent decline of honey bee colonies in North America and Europe. Because in tropical climates worker brood rearing and varroa reproduction occurs all year round, it could be expected that here the impact of the parasite will be even more devastating. Yet, this has not been the case in tropical areas of South America. In Brazil, varroa was introduced more than 30 years ago and got established at low levels of infestation, without causing apparent damage to apiculture with Africanized honey bees (AHB). The tolerance of AHB to varroa is apparently attributable, at least in part, to resistance in the bees. The low fertility of this parasite in Africanized worker brood and the grooming and hygienic behavior of the bees are referred as important factors in keeping mite infestation low in the colonies. It has also been suggested that the type of mite influences the level of tolerance in a honey bee population. The Korea haplotype is predominant in unbalanced host-parasite systems, as exist in Europe, whereas in stable systems, as in Brazil, the Japan haplotype used to predominate. However, the patterns of varroa genetic variation have changed in Brazil. All recently sampled mites were of the Korea haplotype, regardless whether the mites had reproduced or not. The fertile mites on AHB in Brazil significantly increased from 56% in the 1980s to 86% in recent years. Nevertheless, despite the increased fertility, no increase in mite infestation rates in the colonies has been detected so far. A comprehensive literature review of varroa reproduction data, focusing on fertility and production of viable female mites, was conducted to provide insight into the Africanized bee host-parasite relationship.
Colony infestation by the parasitic mite, Varroa destructor is one of the most serious problems for beekeeping worldwide. In order to reproduce varroa females, enter worker or drone brood shortly before the cell is sealed. To test the hypothesis that, due to the preference of mites to invade drone brood to reproduce, a high proportion of the mite reproduction should occur in drone cells, a comparative study of mite reproductive rate in worker and drone brood of Africanized honey bees (AHB) was done for 370 mites. After determining the number, developmental stage and sex of the offspring in worker cells, the foundress female mite was immediately transferred into an uninfested drone cell. Mite fertility in single infested worker and drone brood cells was 76.5 and 79.3%, respectively. There was no difference between the groups (X(2)= 0.78, P = 0.37). However, one of the most significant differences in mite reproduction was the higher percentage of mites producing viable offspring (cells that contain one live adult male and at least one adult female mite) in drone cells (38.1%) compared to worker cells (13.8%) (X(2)= 55.4, P < 0.01). Furthermore, a high level of immature offspring occurred in worker cells and not in drone cells (X(2)= 69, P < 0.01). Although no differences were found in the percentage of non-reproducing mites, more than 74% (n = 85) of the mites that did not reproduce in worker brood, produced offspring when they were transferred to drone brood.
Varroa destructor is known to be the most serious parasite of Apis mellifera worldwide. In order to reproduce varroa females enter worker or drone brood shortly before the cell is sealed. From March to December 2008, the reproductive rate and offspring mortality (mature and immature stages), focusing on male absence and male mortality of V. destructor, was investigated in naturally infested worker and drone brood of Africanized honey bees (AHB) in Costa Rica. Data were obtained from 388 to 403 single infested worker and drone brood cells, respectively. Mite fertility in worker and drone brood cells was 88.9 and 93.1%, respectively. There was no difference between the groups (X(2) = 3.6, P = 0.06). However, one of the most significant differences in mite reproduction was the higher percentage of mites producing viable offspring in drone cells (64.8%) compared to worker cells (37.6%) (X(2) = 57.2, P < 0.05). A greater proportion of mites in worker brood cells produced non-viable female offspring. Mite offspring mortality in both worker and drone cells was high in the protonymph stage (mobile and immobile). A significant finding was the high rate of male mortality. The worker and drone brood revealed that 23.9 and 6.9%, respectively, of the adult male offspring was found dead. If the absence (missing) of the male and adult male mortality are taken together the percentage of cells increased to 40.0 and 21.3% in worker and drone cells, respectively (X(2) = 28.8, P < 0.05). The absence of the male or male mortality in a considerable number of worker cells naturally infested with varroa is the major factor in our study which reduces the production of viable daughters in AHB colonies in Costa Rica.
The ectoparasitic mite Varroa destructor is currently the most important pest of the honey bee, Apis mellifera. Because mite reproduction occurs within the sealed cell, the direct observation of varroa activity inside the cell is difficult. A video observation method using transparent polystyrol cells containing infested brood was used to analyze the behavior of varroa mites in worker brood of Africanized honey bees. We recorded how mites feed on the larva and pupa, construct a fecal accumulation site and how the bee larva carried out some longitudinal movements around the cell. The feeding activity of the foundress mite varies during the course of the cycle. On the prepupa mites were found to feed often (0.3 +/- 0.2 bouts h(-1)) for a period of 8.7 +/- 8.4 min h(-1) and there was no preference for a specific segment as feeding site. On the opposite, during the pupal stage mites fed less often (0.1 +/- 0.1 bouts h(-1)) for a period of 6.2 +/- 4.0 min h(-1) and almost always at a particular site (92.4%). On pupa, 83.7% of the feeding was on the 2nd abdominal segment (n = 92), and only few perforations were found on the thorax. Varroa shows a preference for defecation in the posterior part of the cell (cell apex), close to the bee's anal zone. We found a high correlation between the position of the feeding site on the pupa and the position of the fecal accumulation on the cell wall. Most infested cells have only one fecal accumulation site and it was the favorite resting site for the mite, where it spent 24.3 +/- 3.9 min h(-1). Longitudinal displacements were observed in 28.0% (n = 25) of the analyzed bee larvae. Turning movements around the cell, from the bottom to the top, were carried out by these larvae, mainly during the second day (47.7 +/- 22.5 min h(-1)), just before pupation, with a total time of 874.9 +/- 262.2 min day(-1) (n = 7 individuals). These results in worker brood of Africanized bees demonstrate adaptations of varroa mites to parasitizing the developing bee inside the capped brood cells.
Neotropical Entomology 36(3): 391-395 (2007) Levantamento da Termitofauna (Isoptera) de uma Plantação de Eucalipto no Brasil Central RESUMO -Os cupins de uma plantação de Eucaliptus urophylla S.T. Blake (Myrtales: Mytaceae) em Buritis, MG, foram amostrados manualmente em 12 transectos. A taxocenose encontrada continha 28 especies pertencentes a Termitidae e Rhinotermitidae. Essa taxocenoce corresponde a um subconjunto da fauna nativa do cerrado anteriormente presente na mesma área. Comparada com a fauna original, ela tem riqueza menor, uma proporção muito menor de humívoros e maior de ceifadores. O exame de 1600 árvores recém-cortadas revelou que apenas três delas (0.2%) apresentavam dano ao cerne causado por Coptotermes sp. Apesar da presença de uma fauna diversa incluindo várias espécies consideradas pragas, os cupins não são considerados um problema significativo nessa região. PALAVRAS-CHAVE:Coptotermes, cupim-do-cerne, cerrado, Minas Gerais, Eucalyptus ABSTRACT -The termite fauna of a plantation of Eucaliptus urophylla S.T. Blake (Myrtales: Mytaceae) in Buritis, Minas Gerais, was manually sampled in 12 transects. The assemblage contained 28 species belonging to Termitidae and Rhinotermitidae. This assemblage corresponds to a subset of the native fauna of the cerrado previously present in this region. Compared to the original native fauna, it has a lower species richness, a much lower proportion of soil-feeders and a higher proportion of litter-feeders. A total of 1600 recently cut trees were examined and only three (0.2%) had damage to the heartwood caused by Coptotermes sp. Despite the presence of a diverse termite fauna including several putative pest species, termites are not considered a significant problem to eucalypt plantations in this region. KEY WORDS: Coptotermes, Minas Gerais, EucalyptusThere are more than 3 million ha of eucalypt plantations in Brazil. The first plantations were established in the State of São Paulo, about 100 years ago, by the São Paulo Railroad Company (Cia Paulista de Estradas de Ferro). Termite damage has been reported to be significant, especially in sites with poor soil previously covered by cerrado vegetation (Valerio et al. 2004).According to Fonseca (1949), from 1908 to 1942, termites killed 70% of the young eucalypts grown by the Cia. Paulista at Guarani, SP. The damage was supposedly caused by termites feeding on the root cortex, especially Syntermes spp. This kind of termite damage is usually limited to the first six months (Berti Filho 1995). After that time the plants become resistant or tolerant to termites. Berti Filho (1995) also lists several other termite genera which have been observed feeding on the roots of eucalypts. However, according to Santos et al. (1990), estimates of termite damage to young eucalypts have been exagerated. Junqueira & Berti Filho (2000), on the other hand, reported that termites killed 9-11% of eucalypt seedlings in a forestry experimental station in the State of São Paulo.Termite damage to adult eucalypt trees was reported by Nogue...
El primer reporte sobre la presencia del pequeño escarabajo de la colmena, Aethina tumida en Centroamérica se dio en El Salvador en el 2013, luego se confirmó en Nicaragua en el 2014, lo cual aumenta el riesgo de su ingreso a Costa Rica. Por lo anterior, en el presente estudio se realizó un muestreo que va de junio 2014 a setiembre 2017, mediante el cual se analizaron 359 colmenas pertenecientes a 62 apiarios ubicados en las provincias de Guanacaste, Puntarenas, Alajuela, San José y Heredia. Se realizaron observaciones de la cría y de las abejas adultas, además se colocaron dos trampas por colmena tipo Cutts Beetle Blaster®, las que permanecieron durante ocho a quince días. Posteriormente las trampas se analizaron en el laboratorio de Patología Apícola del CINAT-UNA. Del total de apiarios muestreados, se confirmó la presencia del pequeño escarabajo únicamente en un apiario centinela ubicado en La Cruz-Guanacaste, en agosto 2015. Por lo anterior, se puede indicar la presencia del pequeño escarabajo A. tumida en colmenas de abejas africanizadas en Costa Rica, con una distribución limitada a la Cruz-Guanacaste. Tomando en cuenta que el escarabajo adulto puede volar y desplazarse junto a enjambres silvestres y la trashumancia de colmenas por parte del apicultor, es importante mantener un monitoreo constante de los apiarios, ya que las condiciones actuales de ausencia en la mayoría de zonas apícolas del país, reportadas en el presente estudio, pueden cambiar.
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