Black wine weevil
The black wine weevil Otiorhynchus sulcatus is an important pest on shrubs, perennials, strawberries and on roof gardens. The brown to black adult beetles of the size of about 7-13 mm are nocturnal and unable to fly. They cause the very typical U-shaped feeding traces at the leaf edges. The eggs are prefferredly laid at the root neck or stem base. As soon as the larvae have hatched, they start to eat the plant roots. The results of their feeding acitvity are growth depressions, wilting or even the death of the plants. Furthermore, the collaps of the plant is accelerated by secondary infections caused by bacteria and fungi. After the pupation of the larva, a new beetle hatches, which is sexually mature after about five weeks and starts to lay new eggs.
In greenhouses and polytunnels, there are several generations of the wine weevil throughout the year, so there are no seasonally fixed development cycles.