Seasonal Pattern of Varroa Mite Infestation and Its Impact on Honey Production in Apis mellifera Beekeeping in Chitwan, Nepal

Abstract

Honeybee colony health and productivity are severely affected by infestations of Varroa mites, which have become one of the most significant threats to apiculture due to their role in colony weakening, reduced productivity, and increased colony losses worldwide. The study was conducted in Chitwan district to assess beekeepers’ perceptions on mite infestation in different seasons, its effect on honey production, and the management practices adopted by the beekeepers. 120 beekeepers were selected using simple random sampling as respondents, and information on beekeeping management practices and beekeepers' perceptions was gathered using a pre-tested semi-structured questionnaire. Beekeepers reported that the Varroa mite infestation and honey production varied across the season. Most of the beekeepers perceived that mite infestation was higher in spring and summer whereas honey production remains comparatively low. Thereafter, infestation gradually decreased, reaching its low level in autumn (10.40%), when honey production increased to 22.60%. However, mite infestation began rising again in winter which is peak season for the honey production as well. The increase in mite infestation may be due to abundant forage availability and increased brood that favor mite population growth. Almost half of the beekeepers experienced moderate loss of honey production of 5-15% due to mite infestation, highlighting the remarkable impact of mite infestation on honey production. Similarly around one fourth of beekeepers reported colony losses due to mite infestation, showing the persistent threat posed by Varroa mites. Beekeepers were practicing various management practices to control the mites; among them formic acid was the most widely used treatment, followed by combinations of formic acid with local treatment measures. Overall, the results highlight that although the mite infestation is manageable their persistent occurrence may reduce honey production and remains significant challenges to sustainable beekeeping in Nepal.