New Possibilities of Poplar Weevil Control by Autumn-Winter Treatment

1987

9 S.

6 Abb., 4 Tab., 11 Lit. Ang.

Bandaufführung

11832

96989

The traditional control methods against the poplar weevil (Cryptorhynchus lapathi L.) consisting in spraying the stem of young poplars in springtime, involve some risks for the already active useful entomofauna. Therefore, the effectiveness of an autumn-winter treatment was tested, also in view of the fact that, under the environmental conditions of northern Italy, the insect overwintering population is quite entirely made up of larvae. Eighteen active ingredients were conpared, all highly effective in spring treatments or provided with a considerable actively at lo temperatures. For chlophyrifos-methyl only, its effectiveness against the insect larvae was assessed at different temperatures between 0 and 15C. Int the control trials, carried out at temperatures below 10C, some of the investigated active ingredients provided excellent results (deltamethrin, alphametrin, phentoate, chlorpyrifos-methyl and others). Terfore, they can be profitably used in autumn-winter treatments, either to guarantee a better disinfestation of the planting stock, or to considerably reduce the insect overwintering population in young stands.