Seed choice in ground beetles is driven by surface-derived hydrocarbons

Area of Science:

• * Entomology
• * Chemical Ecology
• * Agroecology

Background:

• * Ground beetles (Carabidae) are vital biological control agents in agricultural systems.
• * Many ground beetle species are omnivorous, consuming both insect pests and weed seeds.
• * The sensory mechanisms underlying seed detection in these beetles are not well understood.

Purpose of the Study:

• * To investigate the sensory mechanisms of seed detection and discrimination in four omnivorous ground beetle species.
• * To identify the primary sensory modalities involved in seed selection.
• * To determine the role of olfactory cues in guiding seed choice.

Main Methods:

• * Conducted multiple-choice seed feeding bioassays with four carabid species.
• * Utilized sensory manipulations, including antennal and palpal ablation.
• * Analyzed seed preferences based on olfactory perception of seed volatiles and surface compounds.

Main Results:

• * Olfactory perception of seed volatiles is the main mechanism for seed detection and discrimination in omnivorous carabids.
• * Long-chain hydrocarbons on seed coats serve as key olfactory cues for desirable seed species.
• * Ablation of antennae and palps significantly impaired the beetles' ability to accurately select seeds.

Conclusions:

• * Olfactory cues are essential for omnivorous ground beetles to detect and discriminate between different seed types.
• * Seed coat surface chemistry, perceived via olfaction, guides seed selection in these insects.
• * Understanding these sensory mechanisms can inform biological control strategies in agroecosystems.