Seasonal incidence, epidemiology and establishment of different pests and disease in laboratory reared Bombus haemorrhoidalis Smith

The bumblebee Bombus haemorrhoidalis Smith are experiencing a great population decline in the current global scenario. An attempt to rear these queens has been made under controlled laboratory conditions but the target has not been achieved successfully. The temperature and relative humidity that required for the rearing of bumble bees are also congenial for the successful establishment and transmission of various diseases and parasites. Therefore, the present study was conducted to study the incidence of different pests and disease in relation to weather parameters. Month wise mortality of B. haemorrhoidalis reared under laboratory conditions in year 2019 was studied. A detailed microscopic study of dead bees was done to find out the cause of queens mortality. Four pests and one pathogen, namely, Physocephala tibialis (Diptera: Conopidae) Aphomia sociella (Lepidoptera: Pyralidae), Parasitus fucorum (Arichnida: Parasitidae), Aethina tumida (Coleoptera: Nitidulidae) and Nosema bombi (Microspora: Nosematidae) caused mortality in observed B. haemorrhoidalis queens. Among these, Nosema was observed in 54.7% dead B. haemorrhoidalis queens. Whereas, conopid fly, wax moth, hive beetle and mites resulted in 18.7, 10.7 10.1, 0.7 and 0.7% mortality, respectively. The infestation of N. bombi exhibits positive significant correlation with temperature and relative humidity, whereas conopid fly infestation showed a negative significant correlation with temperature. Wax moth, hive beetle and mites attacking the bumblebees showed no correlation with temperature and relative humidity. The current study advocates the adoption of practical management practices for successful rearing and commercialization of bombiculture.