The use of a mix of parasitoids to control all aphid species on protected vegetable crops

Abstract: Viridaxis is a Belgian company which developed a new, plant-less way of massrearingaphid parasitoids. Due to its innovative and unique technology, Viridaxis has been able toadd one new selected parasitoid species every year. A parasitoid is a wasp able to parasitizeaphids in a relatively host-specific way. These natural enemies of aphids are used in organicand/or Integrated Pest Management (IPM) strategies. In order to apply the matching parasitoidagainst a given aphid species, the aphid has to be detected in the crop and subsequentlyidentified. By the time the aphids are spotted by the grower and then identified by himself or aspecialist, it is usually more difficult to gain control over an increasing aphid population.Viridaxis developed a new concept of aphid control, based not on the species identified but onthe crop treated. To protect vegetables against their main aphids, VerdaProtect contains sixdifferent species of natural aphid enemies. When used preventively, it is able to control allcommonly appearing aphids attacking vegetable crops. Here, we show the results of trialsconducted in 2011 in sweet pepper crops. In Germany, the comparison of the VerdaProtectstrategy with the “traditional” biological strategy based on single species release showed that theVerdaProtect strategy was as efficient as the traditional strategy in controlling aphids but wasmuch easier, less time consuming and also much cheaper. The trial in a company growing sweetpepper in a large scale hydroponic greenhouse in integrated pest management in The Netherlandsshowed a high efficacy of the parasitoid mix and contrary to the widely used banker plantsstrategy, it did not encounter the widespread hyperparasitoid problem.