Comparative biology, host preference behaviour and biological control of Melolontha cuprescens, Melolontha furcicauda and Melolontha indica (Coleoptera: Scarabaeidae)

ABSTRACT

Melolontha is a polyphagous pest in north-western Himalayan regions. Present study was conducted to understand the biology, host preferences, oviposition potential on different hosts and biocontrol of Melolontha sp. In the biennial life cycle of these Melolontha species, M. cuprescens had the longest larval stage (614 days), followed by M. furcicauda (581 days) and M. indica (602 days). Respective body length of fully fed first, second and third instar grubs ranged between 10.01–16.87 mm, 21.87–24.18 mm and 40.13–58.20 mm. A significantly positive relationship was observed between feeding and the number of eggs laid per female beetle. Rose was most preferred by M. furcicauda and M. indica while M. cuprescens beetles preferred apple. The LC₅₀ values of dip treatment and oral feeding of CH I isolate of Beauveria brongniartii for first, second and third instar of M. cuprescens grubs were 5.45 × 10⁵ and 5.47 × 10⁵; 5.98 × 10⁵ and 5.52 × 10⁵; and 6.27 × 10⁵ and 5.56 × 10⁵ conidia/ml, respectively. Therefore, highly effective and economic biological control of Melolontha grubs is possible through Beauveria brongniartii.

KEYWORDS:

• Melolontha
• biology
• oviposition potential
• host preference
• Beauveria brongniartii

Acknowledgements

The authors are thankful to the Head, Department of Entomology, CSK Himachal Pradesh Agricultural University, Palampur, Himachal Pradesh, India, for providing laboratory and other facilities. We are also thankful to the Network Coordinator, All India Network Project on Soil Arthropod Pests, Jaipur, India and Director of Research, CSK HPKV Palampur, for supporting this research work. We are grateful to the National Bureau of Agricultural Insect Resources, Bengaluru, India, for assisting this research work.

Disclosure statement

No potential conflict of interest was reported by the author(s).