Evaluation of wheat ear insects in large scale field in central Germany

Wheat ear insects in large scale winter wheat field in Salzmünde (Saxsony-Anhalt) central Germany were evaluated. The present study aimed at studying the abundance of wheat blossom midges WBM, Sitodoplosis mosellana (Géhin), Contarinia tritici (Kirby) and thrips, Limothrips cerealium (Haliday) and Haplothrips tritici (Kurdjumov). Infestation in winter wheat during the growing seasons 2007, 2008 and 2009 was evaluated. Three methods were used to determine population densities and damage of wheat midges and thrips; pheromone traps, inspection of ear insects and water traps. A strong correlation between midge’s catches and weather conditions was obtained in field observations. A positive correlation between pheromone catches and ear infestation levels was recorded; it was higher in 2008 than in 2009. On the other hand, in 2007 there was no synchronization; S. mosellana hibernated emerged too late to coincide with the susceptible wheat growth stages. The chemical treatment applied at 2008 for highly infestation; there were significant differences in thrips and midge numbers between treated and untreated. Thrips and midge numbers were lower in the treated than in control. The high midge populations in water traps were recorded at growth stages 77-79 and 83 and the low populations were recorded at GS 75 and 75-77. This gives a reliable base for decision making to midges control.