Effect of agrochemicals on the pattern of visitation of honey bees (aem>Apis mellifera ) in melon ( Cucumis melo ) flowers in Brazilian Northeast

Abstract

Background: Lately pollinators of the main crops have presented a decline with considerable economic impacts. Among the probable causes of this problem is the inadequate use of pesticides, mainly in monocultures. The culture of melon ( Cucumis melo ) is dependent on pollination services by honey bees ( Apis mellifera L.). However, agrochemicals are not applied with special care to the visitation of bees in cultivated areas at the irrigation pole of Petrolina-Juazeiro, located in Brazilian Northeast. Therefore, the objective of this study was to evaluate the effect of agrochemicals pulverization on the pattern of visitation of honeybees to melon flowers. Results: In the dry season the honey bees’ visits occurred since 6 a.m. in larger numbers than in the wet season. Indeed, in the dry season, there was a negative effect of the application of agrochemicals on the frequency of visitation by A. mellifera , after the 1st, 2nd, and 5th day of pulverization. This effect was more intense on the 1st day, when there were registered average values smaller than one visit, independently of the flower type and time of the day. Moreover, the first visits were observed only from 8 a.m. On the 5th day the average numbers of visits were still lower than in the dry season, but higher than on the previous days. Conclusion: Comparing both seasons, we found that the frequency of visitation observed in wet season was lower than that found in dry season. This indicates that the productivity of the melon in the first period can be reduced by the excessive application of agrochemicals, since there will be a reduction of the pollination services. Keywords: melon, pollination, agrochemicals, honey bees, Apis mellifera