Efficacy of freezing and gamma radiation for controlling of Galleria mellonella (Lepidoptera: Pyralidae)

Abstract Background The greater wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae), is a serious insect pest of honey bee combs in hives. Therefore, controlling this pest is very important for protecting bee hives. Methods The efficacy of freezing and gamma irradiation was tested against Galleria mellonella larvae. Fourth-instar larvae of G. mellonella were exposed to freezing temperature (− 16°C) for 5, 15, 30, 45, and 60 min. In the other experiment, the larvae were irradiated with four doses of gamma radiation (100, 200, 400, and 800 Gy). Mortality rates for larvae were recorded during 7 days. After seven days, the treated and untreated surviving larvae were fed a natural diet and kept under the same conditions. They were then observed every day until full pupation and adult emergence. The percentages of pupation, adult emergence, and survival descendant from the treated and the untreated larvae were counted. Results The mortality of G. mellonella larvae was significantly increased with the increasing irradiated times to freezing at − 16°C. The total larval mortality occurred after 1 day at − 16°C and exposure time (60 min). Also, the complete suppression of pupation and adult emergence of G. mellonella from treated larvae was achieved by − 16°C at the exposure times (45 and 30 min), respectively. On the other hand, the highest larval mortality (71.4 %) was recorded after 7 days of exposure at 800 Gy. The complete inhibition of adult emergence was obtained by the dose (400 Gy). Conclusions These findings indicate that freezing and gamma radiation could be useful approaches for controlling G. mellonella .