The relationship between morphological and behavioral mimicry in hover flies (Diptera: Syrphidae)

Area of Science:

• Evolutionary Biology
• Behavioral Ecology
• Insect Mimicry

Background:

• Palatable species often mimic unprofitable models (Batesian mimicry) to avoid predation.
• Mimics may use behavioral strategies to enhance visual resemblance or compensate for poor morphological similarity.
• Hover flies (Syrphidae) provide a model system to study mimicry due to their diverse interactions with hymenopteran models.

Purpose of the Study:

• To investigate whether hover flies employ behavioral mimicry to enhance their defense against predators.
• To determine if behavioral mimicry is associated with morphological similarity to hymenopteran models.
• To test contrasting predictions regarding the role of behavior in Batesian mimicry.

Main Methods:

• Behavioral assays were conducted on 57 field-caught species of mimetic hover flies.
• Morphological similarity to potential hymenopteran models was quantified.
• A custom phylogeny was used to control for evolutionary relatedness in the analysis.

Main Results:

• Behavioral mimicry (mock stinging, leg/wing waving) was observed in large wasp mimics from the genera Spilomyia and Temnostoma.
• These behavioral mimics were also good morphological mimics.
• However, not all morphologically good mimics exhibited behavioral mimicry.

Conclusions:

• Behavioral mimicry in hover flies appears to augment, rather than compensate for, strong morphological resemblance.
• The evolution of behavioral mimicry may not benefit all visually similar species.
• These findings highlight the complex interplay between morphology and behavior in defensive mimicry systems.