Populations’ synchronization of aphids (Homoptera: Aphididae) and ladybird beetles (Coleoptera: Coccinellidae) and exploitation of food attractants for predator

Abstract

Field Surveillance was conducted on synchronization in populations build up of aphids and its predator ladybird beetles (Coccinellidae) in canola [rape] (Brassica napus L.) field. Studies reflected that there was no appropriate synchronization between populations of the prey and its predator that appeared later. The nominal population of the predator was recorded when the population of the aphid was at its peak and the pest started to migrate from the canola fields. This gap may only be filled up by the use of environmentally non-toxic chemicals to attract predator for acceptable and ecofriendly suppressive measures of insect pest. Since behavioral approaches are key elements in integrated pest management, insect’s food attractants technique to attract aphid predator coccinellids ladybird beetles was tested using the foliar application of protein hydrolysate, casein, sugar and torula yeast. Results demonstrated that increased population of lady beetle and reduced aphid damage occurred in treated plants in comparison with those in control. Treatments consisting of protein hydrolysate and sugar were more efficacious where the uppermost predator numbers were observed than in caseinapplied treatment where the slight population was detected. Studies further revealed that the predator observed in torula yeast treated crop were moderate in numbers but significantly higher than in non-treated. The aphids’ infestation was significantly low in protein hydrolysate bait spray treatment followed by sugar and torula yeast treatments. An identical trend of grain yield was recorded in the chemically treated crop in comparison with control where dropped yield was recorded. These results suggest that predator-attracting strategy may be used for aphid management.