Sex Pheromones From <scp> <i>Linyphia triangularis</i> </scp> (Araneae: Linyphiidae) and <scp> <i>Aphidoletes aphidimyza</i> </scp> (Diptera: Cecidomyiidae) Are Promising Attractants for <scp> <i>Aphidoletes aphidimyza</i> </scp> (Diptera: Cecidomyii

ABSTRACT Although Aphidoletes aphidimyza (Rondani) is a predator of aphids, its biocontrol efficacy depends largely on oviposition behaviour. Previous studies have shown that spider webs can attract A. aphidimyza and enhance its oviposition. It has been hypothesized that sex pheromones from spider webs and A. aphidimyza itself may affect its mating and oviposition, but this remains unconfirmed. In our study, we selected (2 R ,7 S )‐diacetoxytridecane (sex pheromone of A. aphidimyza ), ( R )‐3‐hydroxybutyric acid (sex pheromone of Linyphia triangularis (Clerck)), and a mixture of these pheromones (at a 10:1 concentration ratio) to investigate their overall response on A. aphidimyza in terms of electroantennogram, behaviour, fecundity, attraction, and aphid control. Our results indicated that these pheromones elicited antennal responses in A. aphidimyza . Specifically, (2 R ,7 S )‐diacetoxytridecane significantly attracted males, while ( R )‐3‐hydroxybutyric acid significantly attracted females; their mixture attracted both sexes. These compounds did not affect oviposition and lifespan of A. aphidimyza . The pheromone mixture attracted significantly more A. aphidimyza than the control group. The number of aphids in the mixture group began to decline 1 day earlier than that in the control group and ultimately achieved a 100% control effect against aphids in a greenhouse. Our findings provide evidence for further exploration of the relationship between L. triangularis and A. aphidimyza . The studied pheromone blend shows potential as an attractant for A. aphidimyza , which could enhance aphid biological control in greenhouses.