Multisensory Integration for Predator Detection and Avoidance in Drosophila melanogaster Larvae

Overview

Predator-prey interactions often involve temporal sequences of sensory cues, where predator-derived chemical signals are detected by the prey before physical contact occurs. Whether prey neural circuits can integrate such olfactory threat cues to enhance defensive responses remain poorly understood in invertebrate systems. In this study, we investigate multisensory integration in Drosophila melanogaster larvae by focusing on the predator-prey relationship between the prey Drosophila larvae and the predator rove beetle Dalotia coriaria. During instances of prey capture, Dalotia utilize a specialized tergal gland that secretes chemicals known as benzoquinones (BQs) — primarily, 1,4-benzoquinone (PBQ) and 2-methyl-1,4benzoquinone (2MBQ) — dissolved in a hydrocarbon solvent. Through the use of quadrant choice assays, we show that early-third instar larvae robustly avoid 2MBQ and the combined PBQ+2MBQ mixture, supported by strong negative preference indices. This avoidance is substantially reduced in orco¹ mutants lacking functional odorant receptor co-receptor signaling, which suggests BQ detection requires canonical olfactory transduction. Interestingly, PBQ alone elicited comparatively weak avoidance despite similar volatility, suggesting that receptor-level specificity in olfactory receptor neurons determines behavioral valence. In a separate priming assay, brief olfactory exposure to BQ volatiles significantly enhanced the intensity and speed of mechanonociceptive escape responses to a subsequent mechanical stimulus in wild-type larvae, as measured by rolling/bend frequency, escape score, and response latency. Once again, this cross-modal priming was absent in orco¹ mutants, indicating that olfactory circuit activation is required to enhance nociceptive circuit gain. Together, these findings support a model in which predator-derived chemical signals serve as anticipatory threat signals that dynamically elevate defensive circuit readiness prior to physical contact. We anticipate our assay to be a starting point for future behavioral experiments investigating neural circuit mechanisms. As for broader implications, cross-modal threat integration may be a strategy conserved across a plethora of other invertebrate predator-prey systems.

Competition history

• CSEF 2026 Zoology (Senior Division) · Entry S-20-12

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

• All Animal Sciences projects
• CSEF Animal Sciences projects
• Every CSEF 2026 project