Canopy-Dwelling Arthropod Response to Rynaxypyr and Lambda-Cyhalothrin Treatments in Maize

Abstract The technology of grain corn production has recently been continuously changing due to spreading of insecticidal in-crop treatments in Europe. The aim of these interventions is to prevent damage caused by serious lepidopterous pests in maize. We carried out in-maize field experiments using two different active ingredients of insecticides in four consecutive years (2014–2017). A field experiment was conducted to compare the effect of applications of rynaxypyr (ANT) and rynaxypyr + lambda-cyhalothrin (PYR) on the canopy-dwelling arthropod community in commercial maize grain acreage. The effects of both ANT and PYR treatments against Ostrinia nubilalis Hübner (Lep.: Crambidae) were tested through four-year field experiments. The quantitative and qualitative assemblages of the perished arthropods and diversity alterations measured by canopy netting and grounded tarpaulins greatly differed in the different insecticide treatments. A significant number of dead arthropods was recorded after PYR treatment. Populations of other natural enemies (Coccinellidae, Chrysopidae, etc.) and endangered species (Calomobius filum, Rossi) were also negatively affected. The arthropod community of the examined maize plots was drastically altered by sprayings, which, among other factors, may account for the mass appearance of the other non-target pest organisms (Aphidae: Rhopalosiphum spp., Miridae: Trygonotylus spp.).