Influência das precipitações pluviométricas e da atividade forrageira das abelhas africanizadas (Apis mellifera L.) no comportamento higiênico / Influence of rainfall and foraging activity on hygienic behavior of Africanized honey bees (Apis mellifera L.)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Hygienic behavior (HB) of honey bees (Apis mellifera ) is a useful and selectable characteristic for resistance to diseases. However, in order to efficiently evaluate and select for this behavior we need to understand the mechanisms involved and how environmental factors influence HB. We examined how time of the day, bee age and behavioral ontogeny, and climatic variables, including temperature, relative humidity and rainfall affect the HB of Africanized bees. We used six colonies of Africanized bees, observation hives and a hive temperature control chamber (colonies had free access to the outside), with temperature and relative humidity sensors and automatic flight activity recorders at the hive entrances. A climatic station placed near the hives was used to record the weather data. The data was analyzed with one way repeated measures ANOVA, ANOVA on ranks, paired t-tests and Spearmans correlation tests. We found that foraging bees can perform HB when the younger bees are removed from the colonies. When the HB tests were run from 12h to 22h (six hours during the day and four hours during the night), 10.8% of the brood was removed; when it was run from 24h to 10h (six hours during the night and four hours during the day, 14.2% of the brood was removed. These percentages were significantly different (three repetitions). The same tests were run from 18h to 4h (10 hours during the night; 28.6% removal) and 6h to 16h (10 hours during the day; 23.9% removal). In this case, there was no significant difference, though there appeared to be a tendency towards greater efficiency at night, similar to what was seen in the experiments with six versus four hours of night-time activity. We hypothesized that unoccupied forager bees may contribute at night; however, when we filmed the behavior of marked bees, those that were seen to make foraging trips did not perform HB at night. We also found that colonies formed only by young bees had more efficient HB than colonies formed by bees of all ages. To determine the influence of climatic conditions, we tested HB two days before rainy days, during rainy days and two days after rainy days; HB was significantly more efficient on rainy days than before and after during spring and summer (when most rain falls). However, during autumn and winter (normally dry seasons) there were no significant differences between days with and without rainfall. The variable relative humidity was inversely correlated with HB, while temperature was not significantly correlated with HB, though we did not test extreme temperatures.

ASSUNTO(S)

hygienic behavior foraging activity comportamento higiênico africanized honey bees precipitações pluviométricas apis mellifera rainfall apis mellifera atividade forrageira abelhas africanizadas

ACESSO AO ARTIGO

Documentos Relacionados