A repellent net as a new technology to protect cabbage crops

Floating row covers or insect-proof nets with fine mesh are effective at protecting vegetable crops against aphids but negatively impact plant health, especially under warm conditions. Furthermore, in control of cabbage insect pests, aphid parasitoids cannot enter the fine-mesh nets, leading to frequent aphid outbreaks. To surmount these difficulties, a 40-mesh-size repellent net treated with alphacypermethrin was studied in laboratory and field tests. Results showed both irritant and repellent effects of the alphacypermethrin-treated net on Myzus persicae (Sulzer) (Hemiptera: Aphididae) and its parasitoid Aphidius colemani (Haliday) (Hymenoptera: Braconidae). Under field conditions, there were no pests on cabbage protected with the repellent net. The repellent net allowed combining a visual and repellent barrier against aphids. Because of this additive effect, repellent nets allowed covering cabbage permanently with adequate protection against all pests.