SIDE-EFFECTS OF COMMONLY USED CROP PROTECTION PRODUCTS IN PEAR ON TWO BENEFICIAL MIRIDAE BUGS.

Abstract

Anthocoris nemoralis, Anthocoris nemorum and Orius spp. are not the only beneficial predatory bugs inhabiting pear orchards in Belgium. Quite often, the Miridae bugs Heterotoma spp. and Pilophorus spp. can be found during spring and summer in these orchards, thereby feeding on several pests such as psyllids, aphids, spider mites, ... . Side-effects are usually assessed on Anthocoris and Orius spp., but due to the potential importance of Miridae bugs in pest reduction, we tested some commonly used crop protection products used in pear cultivation on Heterotoma planicornis and Pilophorus perplexus (residue-based tests in petri-dishes). One day after treatment, mortalities already could be observed for some products. Seven days after treatment, abamectin, deltamethrin and thiacloprid were considered the most toxic products as stated by the IOBC classification. This outcome was then analysed with regard to different treatment schedules, providing insights in potential side-effects on crop protection treatments on the composition of beneficial fauna in pear orchards.