Aphid control with semiochemicals

The objectives are to develop odour-based methods to reduce the dependence on conventional chemical control against aphids and to contribute to the development of integrated breeding and plant protection systems.

Background. Aphids are one of the most important groups of pest insects in Swedish agriculture and horticulture. This is true also for other parts of northwestern Europe. Aphids damage the plants by sucking nutritious liquids and sometimes also by transferring virus diseases that affects the plants. The damage reduces the yield and affects the quality of the harvested product. This causes extensive use of chemical insecticides against aphids. The project focuses on a number of aphids infesting spring cereals and green house crops.

Pheromones and plant odours. The project investigates the chemical communication of aphids. The aggregation pheromones are identified in order to develop effective monitoring traps. In addition, a compound produced by the winter host (aphids overwinter on other plant species than those infested during the summer) and affecting the spring migration and establishment of the aphids in the cereal, is investigated.

Plant defence. An aphid infestation affects the plant, which reacts by releasing volatile substances. These substances affect other plants so that they become less attractive to the aphids. Experiments to identify the active compounds are in progress.

Natural enemies. Within the project also the possibility to attract natural enemies to aphid infested areas by different odours are investigated. One compound that contributes to the aggregation of ladybird beetles before winter has been identified.

Applications. In order to suppress aphid populations by means of chemical communication a combination of different strategies will be needed. Experiments in larger scale, including yield losses, are in progress.

Place of research: Department of Entomology, Swedish Univ. of Agricultural Sciences, Ultuna (in Swedish)

Participating scientists: Jan Pettersson (project leader), Elham Ahmed, Robert Glinwood, Velemir Ninkovic