A new study published in the journal Behavioral Ecology and Sociobiology explores how wasps accept outsiders to their colonies and whether age makes a difference. The study, by University of Miami biologist Floria Mora-Kepfer Uy, used the social wasp Mischocyttarus mexicanus to compare new colonies versus established ones, and to compare the acceptance rate of young wasps versus older wasps.

Nest-switching is common during the initial period of colony establishment, when individual wasps try to join other colonies, and existing members have to decide whether to accept or reject new comers. The wasps recognize nestmates from non-nestmates using chemical signals that are specific to each colony.

This video shows a female wasp marked with pink paint that was a recently accepted non-nestmate who became a subordinate worker. A resident female flies in and forces the newly accepted wasp back into the nest to guard the eggs and larvae.

“These colonies are composed exclusively of females and they make decisions on the colony composition depending on the social and ecological pressures they are exposed to,” said Mora-Kepfer Uy, a lecturer in the College of Arts & Sciences.

New colonies may have a stonger need for new workers, making them more likely to take the risk of accepting strangers. Older colonies — ones that have more to lose and less need for new workers — are more likely to reject newcomers.

“If non-nestmates are accepted, they may either become a worker in the colony or instead attempt to take over the reproductive-dominant role, steal, or cannibalize the colony’s offspring,” said Mora-Kepfer Uy. “Females are, therefore, trying to balance the potential benefits of having additional help with the possible costs of new members acting selfishly.”

Read more at:

– Context-dependent acceptance of non-nestmates in a primitively eusocial insect