Potency of Bio Magic (Metarhizium anisopliae fungus) and gamma radiation in the black cut worm, Agrotis ipsilon (Hufnagel) larvae

Abstract

Abstract Background Integrated pest management is one of the ways to solve the problems of increased outbreaks of pests induced by the effects of climate change. Therefore, the present investigation was carried out to study the integrated effect of entomopathogenic fungus, Metarhizium anisopliae and gamma radiation to control 5th instar larvae the black cut worm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), under laboratory condition. The leaf dipping technique was used to test the pathogenicity of different concentrations of the fungus against normal and F1 (resulted from irradiated male parent pupae with 100 Gy) larvae. As well as, the changes in the haemocytes were studied using LC50 of M. anisopliae of both treatment (unirradiated and F1 larvae). Results The results showed that larval mortality percentage was both M. anisopliae virulent and time dependent. Furthermore, F1 larvae were more susceptible to M. anisopliae where 100% mortality was recorded after 3 days of M. anisopliae treatment at 8 × 105 spores/ml concentration. While mortality of normal (unirradiated) larvae reached 40% at the same time and concentration. The haematological examination of larvae revealed significant reduces in total haemocyte counts, differential percentage and increase in morphological malformation of the haemocytes which was pronounced by F1 + M. anisopliae LC50. Conclusions According to the obtained results, the gamma irradiation increased the pathogenicity of the fungus against the 5th instar A. ipsilon larvae. So, the combination between the two control tools may provide a satisfactory integrated control program after further field trials.

Keywords

• Agrotis ipsilon
• Gamma radiation
• Entomopathogenic fungi
• Metarhizium anisopliae
• Mortality
• Haematological studies