Behavioural Response of Seven-Spotted Ladybird Beetle, Coccinella septempunctata (L.) (Coleoptera: Coccinellidae) towards Different Aphids and their Host Plants

Abstract

The current study was investigates the olfactory response of the predatory beetle, Coccinella septempunctata to various host plants and their associated aphids under laboratory conditions at 27±20C and RH 65±5 %. Using a four-arm olfactometer, the beetles' attraction to healthy and aphid-infested mustard, wheat, rose, and chrysanthemum was evaluated. The results revealed that C. septempunctata showed a significantly higher attraction to aphid-infested plants compared to healthy plants or aphids alone. Among the treatments, mustard infested with Lipaphis erysimi (Kaltenbach), wheat infested with Rhopalosiphum maidis (Fitch), rose infested with Macrosiphum rosae (Linnaeus), and chrysanthemum infested with Macrosiphoniella sanborni (Gillette) elicited the strongest responses. These findings support the hypothesis that predatory coccinellids are more attracted to the olfactory cues emitted by aphid-infested plants, likely due to the release of semiochemicals in response to herbivore damage. This behavior enhances the effectiveness of C. septempunctata as a biological control agent by improving its ability to locate prey in agricultural ecosystems.