Specificity of an ant-lycaenid interaction.

Area of Science:

• Ecology
• Entomology
• Animal Behavior

Background:

• Lycaenid butterflies often engage in mutualistic relationships with ants.
• This mutualism involves butterfly larvae providing rewards to ants in exchange for protection.

Purpose of the Study:

• To investigate the specificity of the mutualistic relationship between Plebejus argus butterflies and ants of the genus Lasius.
• To determine which ant species are preferred by different life stages of P. argus.

Main Methods:

• Experiments were conducted to assess the attractiveness of Plebejus argus eggs, larvae, pupae, and adults to different ant genera (Lasius, Myrmica, Formica).
• Reciprocal trials were performed using two populations of P. argus naturally associated with Lasius niger and Lasius alienus.

Main Results:

• Lasius ants showed significant attraction to P. argus larvae and pupae, while other ant genera showed less interest.
• First instar larvae were actively recruited by Lasius workers, and older larvae and pupae were highly attractive.
• Teneral adults were palpated by Lasius but attacked by Myrmica and Formica.
• Larvae exhibited a slight preference for their naturally associated Lasius host species, suggesting a genetic basis for host specificity.

Conclusions:

• Plebejus argus is a specialist associate of ants in the genus Lasius.
• The observed differentiation in host preference between P. argus populations suggests a genetically based specialization.
• This study highlights the intricate and specific nature of ant-butterfly mutualisms.