Biological notes on nesting biology, development and natural enemies of Braunsapis mixta, a pollinator of cashew

Abstract

Native bees play a vital role in the pollination of different flora in an ecosystem. But the natural history of most native bee species is unknown, and knowledge about natural history helps in understanding their social evolution, and further protecting and conserving the bee species. Braunsapis mixta (Smith) is a common stem-nesting bee and a widespread endemic species of Southern Asia. This study aimed to record the nesting biology, development and natural enemies of B. mixta, which is an important pollinator of cashew. Nests of B. mixta were found in the dried sticks and pruned cut ends of cashew stems. A total of 442 nests were collected, of which 64% of the active nests were single-adult nests and 20% were of two adults. Eggs were found at the interior end, followed by larvae at varied developmental stages and pupae. The maximum number of nest occupants in a nest was 41, in which four were adults and a maximum of 11 adults were recorded in a single nest. The maximum number of females found in a nest was nine. A significant positive correlation was obtained between the number of adults and their immature stages. Egg production and brood maturation occurred throughout the year. The mean incubation period of eggs was 5.32 days. Rearing of larvae could not be achieved in the laboratory. The pupal period lasted for 11–14 days. The parasitoids recorded on B. mixta include Neochalcis breviceps and Diomorus nr. indicus.

Keywords:

• Apidae
• allodapine
• social insect
• eusocial
• stem nesting
• nest protection

Acknowledgements

The authors thank Dr S. Manikavasagan, Professor of Entomology, Annamalai University, Tamil Nadu, and Dr H.M. Yeshwanth, Dept of Entomology, GKVK, Bengaluru, India, for identifying few natural enemies. The first author also thanks Dr C. Prasantha, GKVK, Bengaluru, and Dr M.P. Schwarz, Associate Professor, Flinders University, Australia, for sharing the related literature and suggestions provided during the study. The help rendered by Dr Murari, PURSE Laboratory, Mangaluru University, for the SEM images of bee species is duly acknowledged. The authors thank the Director, ICAR-DCR, Puttur, and Director, ICAR-NBAIR, Bengaluru, for the facilities and support provided during the investigation.

Disclosure statement

No potential conflict of interest was reported by the authors.