Does the wasp know where she is? Capability, mechanism and ontogeny of orientation in the primitively eusocial wasp <em>Ropalidia marginata</em> — ASN Events

Does the wasp know where she is? Capability, mechanism and ontogeny of orientation in the primitively eusocial wasp Ropalidia marginata (#864)

Souvik Mandal 1 , Raghavendra Gadagkar 1
  1. Indian Institute of Science, Bangalore, KARNATAKA, India

Knowing the current position with respect to an intended goal, the orientation capability, is essential to perform homing. Social insects constitute an excellent system for studying these phenomena. To check whether the forager wasps can orient towards their nests if experimentally dislocated, we released foragers of tropical primitively eusocial wasp Ropalidia marginata in several distances from their nests without providing food and recorded their vanishing bearing. When released near their nests, they did not head towards their nest. However when released further, even from completely novel sites, surprisingly they oriented towards their nests. When food was given to the wasps prior to release near the nest, the paradox was solved as they headed towards their nests. This happened because when released near to their nests without food, instead of heading towards their nests, wasps might have gone for foraging. But when released further, wasps might have preferred to reach near the nest first and so, they headed towards their nests. This result indicates that the forager wasps can orient towards their nest irrespective of their familiarity with the release site and its distance from their nest. Further investigation showed that they rarely perform orientation flight when released near their nests, but when they were transported far from nest, radial orientation flight constitutes one of the key mechanisms of orientation. It thus appears that the wasps orient themselves with the help of surrounding landmarks when they are visually familiar but switch to other methods of orientation when they find themselves in unknown territory. To study the ontogeny of orientation capability we focused on the orientation flights at their nests, of outgoing and incoming wasps of known age. We found that the type and duration of orientation flights change with the age of the wasps.