Biological activity of certain natural products against Varroa destructor (Acari:Varroidae) and their selectivity against Apis mellifera (Hymenoptera: Apidae)

The ectoparasitic mite, Varroa destructor (Anderson and Trueman) is considered one of the most serious pests of beehives, causing tremendous damage to honey bees, Apis mellifera L. and great economic loses to the beekeeping industry.  Efficacy of six natural plant products (Pomegranate, Garlic, Marjoram, Harmal, Black cumin, Ambrosia) was evaluated against varroa mite and Apis mellifera 2018 season. The tested materials were applied in different methods of application: spray method, dusting and fumigation methods. Results showed that fumigation was more efficient than spraying while treatment as dusting of the powder of these materials recorded the lowest efficacy. Treatment with Pomegranate fumigation resulted the highest efficacy against Varroa mite followed by Garlic and Marjoram (94.6, 89.8 and 89.8 % reduction for adult infestation) and 85.6, 86.1 and 82.4% for brood infestation.  Spraying with extract of Harmal showed the highest efficacy against Varroa mite (91.88%) followed by Pomegranate (91.06%), Black cumin 89.11% and Garlic 88.82 % reduction for adult infestation.  Among the tested plant products used as dusting the infested bee colonies, powder of Marjoram, Harmal, Black cumin and Garlic recorded the highest efficacy against Varroa mite infested adult (94.67, 94.67, 94.42 and 93.15 Reduction %). All products haven’t any effect against Apis mellifera and colonies treated with these materials gave a significant high honey productivity compared with control. Results indicated that using plant products in controlling Varroa mite through IPM program seem to be the ideal way for controlling this mite; hence these materials are available, safety to environment, selective to bees, easy in application and economically cheap