Diversifying arthropod assemblages of greenhouse pepper — Preliminary results

Recent years of studies have suggested that the common crab spider (Xysticus kochi) has a great potential against the western flower thrips (Frankliniella occidentalis) . The efficiency of applying a single predator against a pest however, is made uncertain by many different factors. Using a mixture of predators on the other hand, can overcome the difficulties of using a single-species agent, since different predators have different environmental demands and preying habits. Our experiments involved releasing a non-selected assemblage of arthropods, collected by sweep-net in alfalfa and stinging nettle, into greenhouse pepper stands. Interestingly, while there were twice as much thrips in the experimental greenhouses than in the control (mainly conventional) ones, crop yields were similar. The ratio of predators-preys in experimental greenhouses was not different from that in the control greenhouses, too. Probably the release of predators and lack of chemical treatments in experimental stands resulted in a 43% increase in the amount of Orius species. In search of a cost-effective, environment-friendly pest management method, the application of a mass-collected, non-selected assemblages of arthropods has a definite potential. Further investigations are needed to increase the efficiency and to monitor the potential drawbacks of this method