Adaptive Defence Strategies of the Stingless Bee, Tetragonula Iridipennis Smith. Against Nest Intruders in a Newly Divided Colony

Abstract

A study was conducted to document nest intruders in newly divided colonies of stingless bees. The nature of the damage, the sequence of activities after colony division, and task allocation in the colony were studied. Three insect invaders - solitary resin bees (Megachile disjuncta, M. cephalotes), ants (Oecophylla smaragdina and Camponotus sp.) and spiders belonging to the family Salticidae and Lycosidae invaded the colonies during the earlier stages of division. The mean number of resin bees and ant invasions was significantly higher during the first week after division. Spiders invaded the hives and formed webs during the second week after division, resin and honey resources are robbed by resin bees and ants. Nest entrance closure was observed at 4.37±0.74 days after colony division guard bee activity from 6.13±1.24 days and foraging activity from 10.63±1.06 days after division. Observations on the task allocation framework after colony division indicated that 69% of bees were involved in hive entrance repair, 18% in colony architecture development, and 13% in tending to newly emerged bees from brood cells. The bees built a complex nest entrance, guarded activity and demonstrated nest closure behaviour in order to protect the nest against intruders. The results of the study are of prime importance for beekeepers to learn how to watch for hive intruders during colony division and to understand the adaptive defence mechanism to protect colonies.