Predatory ladybirds avoid ant cuticular undecane, reducing predation and oviposition

Area of Science:

• Chemical Ecology
• Insect Behavior
• Biological Control

Background:

• Ladybirds (Harmonia axyridis) are natural predators facing interference from ants (Lasius niger).
• Ants defend aphid colonies, limiting ladybird foraging and oviposition sites.
• The role of ant cuticular hydrocarbons (CHCs) in mediating ladybird behavior is not well understood.

Purpose of the Study:

• To investigate the behavioral responses of Harmonia axyridis to Lasius niger cuticular hydrocarbons (CHCs).
• To identify specific CHC components responsible for mediating these interactions.
• To understand how these chemical cues influence ladybird feeding and egg-laying.

Main Methods:

• Behavioral assays to observe ladybird responses to ants and their CHCs.
• Chemical analysis to identify CHC profiles of Lasius niger.
• Electrophysiological analysis (EAD) to detect active CHC components.

Main Results:

• Harmonia axyridis exhibited significant avoidance behavior towards Lasius niger and its CHCs.
• Undecane was identified as an electroantennographic detection (EAD)-active CHC.
• Undecane exposure significantly reduced predation of aphids and oviposition by ladybirds.

Conclusions:

• Ladybirds avoid Lasius niger CHCs, particularly undecane, which modulates their feeding and egg-laying.
• Findings advance understanding of chemically mediated interactions in multitrophic systems.
• Results provide a basis for future studies on ant chemical cues in biological control.