Seasonal Variation of Hornets in the Apiaries of Natural History Museum Swayambhu,kathmandu

Abstract

Predation of honeybees in the apiaries of Natural History Museum, Swayambhu, Kathmandu had been a serious problem causing a significant loss of bees in the apiaries. The aim of this study was to investigate the different species of hornets occurring seasonally during 2016 and 2017 at the apiaries there. Two traps with bait made from locally available substances (mixture of local beverage, water, honey, egg, orange, banana and sugar) were set on the branches of trees near the hives. With periodic replacement of the bait (once a week), number of hornets which fell into the trap were collected, counted and identified. Five species of hornets (Vespa velutina, Vespa. basalis, Vespa tropica, Vespa orientalis and Vespa magnifica) were collected in the whole study. The highest average occurrence of hornets was found in October (23.75±1.920) due to colony expansion and lowest occurrence was found in January (0.25±0.25) due to over-wintering. V. velutina made the highest occurrence in number (951) followed by V. basalis (122) while V. magnifica made the lowest occurrence (1) followed by V. orientalis (3).The Simpsons, Shannon and Evenness indices for the species were 0.214, 0.39611 and 0.246 respectively. Monthly average occurrence of hornets was statistically significant with p-value 0.87592465 (11, 59) at 0.05 level of significance for one way ANNOVA. Occurrence of hornets, on the other hand, was positively correlated to temperature (0.5212) and humidity (0.6924).