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Due to the length of egg-laying period (> 80 days), two applications of insecticides against cabbage stem weevil (Ceutorhynchus pallidactylus Marsh.) are currently needed. However, resistance of pollen beetle (Brassicogethes aeneus F.) to pyrethroids complicates the choice of suitable insecticide for the second application. The active ingredients cypermethrin, etofenprox, pymetrozine, indoxacarb and chlorpyrifos-ethyl applied as second spring applications to winter oilseed rape crops were assessed under field conditions from 2016 to 2018 to ascertain how they could reinforce the effects of the first spring application (beta-cyfluthrin) on cabbage stem weevil. Chlorpyrifos-ethyl and etofenprox strengthened the effects of the first spring spray on cabbage stem weevil markedly more than cypermethrin. Pymetrozine and indoxacarb, effective on resistant populations of pollen beetles, showed the lowest contribution to increase the effects. Indoxacarb showed a low effect on C. pallidactylus in laboratory tests too. The impacts of the bans on active ingredients chlorpyrifos-ethyl and pymetrozine are discussed.

Bruchus pisorum L., is an economically important pest of field pea (Pisum sativum L.) crops worldwide, however, no fully effective methods (conventional, alternative) of its control exist now. To fill this knowledge gap, possibilities of trap cropping were tested in the years 2015–2017. Two field pea varieties differing in the start of flowering, and one spring barley variety, were used to design four different types of crops, that were compared in large plot trials (2.82 ha). It was hypothesized the females would prefer zones planted with early flowering variety for oviposition. In all three seasons, females placed more eggs on pods in the parts of plots planted with the early flowering variety, and positive aggregation of the eggs and infested seeds were recorded there too. In cases where the egg-laying period is shorter than 14–21 days, the early flowering variety located at the margins should serve efficiently as a trap crop.

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