Speaker
Description
Phytophagous insects rely on many different sensory cues to locate their host plants, including visual, olfactory, gustatory, and tactile stimuli [1]. These cues are processed by sensory systems and integrated in the brain to elicit a proper behavioural response. Chnootriba elaterii is an injurious pest of cucurbits in the Mediterranean Region [2] which causes serious damage mainly in organic crops. This study investigates the host location process of this important pest under controlled conditions using both a Y-Tube olfactometer and an open Y-Track olfactometer. Our investigations reveal that a combination of olfactory and visual cues from the host plant synergistically guides the ladybirds toward their host plant while females demonstrate an inability to differentiate between host and non-host plants using either olfactory or visual cues alone. Cucumis melo and Vicia faba var. minor plants are used as visual and olfactory stimuli while dummy plants as visual stimuli. Among the main colours generally perceived by insects, such as yellow, green, red, blue and black [3], green colour is a more significant contributor to the host location process than olfactory cues. We find that green dummy plants crafted from cardboard serve as potent supernormal stimuli for the melon ladybird. These findings offer insights into the host location mechanisms of Coccinellidae and may pave the way for the development of visual or chemical traps for effective monitoring and control this significant crop pest in the Mediterranean Basin.
