TO EVALUATE THE OCCURRENCE, PREVALENCE AND DISTRIBUTION OF VARROA MITE (Varroa destructor) AND ASSOCIATED INSECT PESTS OF HONEY BEE (Apis mellifera) IN UASIN GISHU COUNTY, KENYA.

Abstract

The loss of Apis mellifera colonies in recent years has been in many regions of the world been alarmingly high. No single cause has been identified for these losses, but the interactions between several factors (mostly pathogens and parasites) have been held responsible. The ectoparasitic Varroa destructor and other associated bee pathogenic viruses have been identified as a marker of dramatic colony losses in the world. The study was aimed at evaluating the occurrence, prevalence and distribution of Varroa destructor and other insect pest of honey bees in six sub-counties in Uasin-Gishu County during May and June 2014. Purposive and convenience sampling was used to select two apiaries in each sub-county. Four bee hives were randomly selected for inspection, direct observation and experimental setup using the sugar roll technique per 100 bees and 100 brood cells was used to collect data and Interview of farmers. Descriptive statistics was used to estimate the prevalence of varroa mite and other insect pest. Chi-square test and odd ratio was performed to find the association between varroa mite infestation and colony strength, Pearson correlation co-efficient was used to test for correlation between the rate of varroa mite infestation and elevation. All the tests were significant at P≤ 0.05 at 95% confidence interval. The interview showed a 67.5% hive occupancy in the surveyed apiaries, all farmers were not aware of varroa mites, however 80% and 70% had knowledge on wax moth and small hive beetle respectively. The study revealed presence of varroa mites in honey bees in all (100%) studied Sub County. Out of 37 inspected honey bee colonies 32 (86.49 %, C.I 95%, 70-93.8%) were found to be infected with varroa mites. The average level of varroa mite infestation in adult bees and brood cells was 59.88±31.45 (mean,±SD), with an average varroa mite infestation of 27.22±12.44 (mean,SD) and 32.67±21.92 (mean,±SD) per 100 adult bees and 100 brood cells per apiary respectively, average infestation per colony of 6.88±2.56(mean,±SD), and 7.80±4.94(mean,±SD), in adult bees and brood cells respectively. The level of varroa mite infestation showed a significant positive correlation with elevation (R2=0.56, p=0.020), The study revealed that honey bees colonies are not affected by varroa mite yet, in fact, there was a statistical significant association between colony strength and level of varroa mite infestation, (χ2 = 5.03, df = 1, P= 0.02), with the infestation in strong colonies being 8.1 times higher than in weak colonies (OR = 8.1, C.I 95%, 1.07 – 35.54). The results showed a wide distribution of other associated honey bee pest, small hive beetle (62.16%), wax moth (21.62%), black ants (32.43%) and earwig (13.52%). Lack of farmers awareness on varroa mite shows that the pest has been introduced recently in the area, therefore, there is a need to further and routine monitoring and surveillance of honey bee colonies so as establish baseline data for initiating control measures