Visual And Chemical Signals Provide Different Information In Polistes Fuscatus Wasps

Most animals communicate using complex signals that convey information in multiple sensory modalities. Testing receiver responses to each signal in isolation as well as the composite signal provides crucial information about how receivers use and integrate information from complex signals. Polistes fuscatus wasps have facial patterns that are visual signals of individual identity and cuticular hydrocarbons (CHCs) that are used for nestmate recognition. Because wasps learn the unique facial pattern of each nestmate, they could potentially use both visual and chemical signals to assess group membership. We test whether P. fuscatus integrate information from visual and chemical signals when assessing conspecifics that approach their nest. We challenged wasps with conspecifics that had color patterns and CHCs of nestmates, color patterns of nestmates and CHCs of non-nestmates, color patterns of non-nestmates and CHCs of nestmates, and color patterns and CHCs of non-nestmates. Wasps with non-nestmate CHCs were treated aggressively, and wasps with nestmate CHCs were treated non-aggressively, regardless of whether the wasps had nestmate or non-nestmate color patterns. Therefore, wasps use chemical signals alone to identify nestmates versus non-nestmates. Receivers do not integrate information from visual and chemical signals during assessment of potential intruders. Instead, visual and chemical signals convey different information and are used in different contexts.