Knot grass (Acronicta rumicis L.) - a new maize pest in Southeastern Poland.

摘要

The knot grass (Acronicta rumicis) is a new pest of maize in the southeastern part of Poland. Its larvae were first detected on maize crops in 2006 near Rzeszow and Przeworsk. Since then, the species has been detected on the local maize crops every year. In 2006-2008 knot grass larvae occurred on maize between July and the end of September and, in 2006, they only fed until the first half of October. The species developed 2 generations a year, not clearly separated from each other. The first generation of larvae fed between July and half of August. They damaged both leaves and silks of the cobs. They fed occasionally on soft kernels in the milk stage. The second generation of larvae appeared at the turn of August and September. Mainly they were seen on leaves and they fed on cob leaves rarely. The period of larval occurrence ended when fresh food was no longer available and with grain harvest.