Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Field trials using the fungal pathogen, Metarhizium anisopliae [Deuteromycetes: Hyphomycetes] to control the ectoparasitic mite, Varroa destructor (Acari: Varroidae) in honey bee, Apis mellifera (Hymenoptera: Apidae) colonies.

Abstract

The potential of Metarhizium anisopliae for controlling the parasitic varroa mite (Varroa destructor syn. Aculops lycopersici) in honey bee colonies was compared with that of the acaricide tau-fluvalinate (Apistan) in field trials in Weslaco, Texas, USA, in 2000. Peak mortality of A. lycopersici occurred 3- 4 days after the conidia were applied. However, the mites were still infected 42 days after the treatment. The 2 application methods tested were dusts and strips coated with the fungal conidia. Both methods resulted in the successful control of mite populations. At the end of the 42-day period of the experiment, the fungal treatments were as effective as Apistan. The data suggested that optimum mite control could be achieved when no brood is being produced, or when brood production is low, such as in the early spring or late fall. M. anisopliae was harmless to the honey bees (adult bees, or brood) and colony development was not affected. Mite mortality was highly correlated with mycosis in dead mites collected from sticky traps, indicating that the fungus was infecting and killing the mites. Because workers and drones drift between hives, the adult bees were able to spread the fungus between honey bee colonies in the apiary, a situation that could be beneficial to bee-keepers. From authors' summary. KEYWORDS: TROPAG | pest mites | Aculops lycopersici | biological control | Metarhizium anisopliae | chemical control | honeybees | USA | Texas.