KISS, Jozsef¹; KOMÁROMI, Judith¹; KHOSBAYAR, Bayar¹; EDWARDS, C. Richard²; HATALÁNÉ, ZSEIIÉR lbolya^3
1 Szent István University, Department of Plant Protection, Gödöllõ, Hungary
² Department of Entomology, Purdue University, IN, USA
³ Csongrád County Plant Health and Soil Conservation Station, Hódmez?vásárhely, Hungary

The spread and buildup of the western corn rootworm (WCR) requires that multiple management strategies be developed for the control of this corn pest. Crop rotation is a primary non-insecticide control strategy used in the USA to control WCR since WCR larvae feed almost exclusively on corn roots (BRANSON and ORTMAN, 1971). However, some entomologists in the USA (EDWARDS, et al., 1997) and in Serbia in Europe (SIVCEV, 1999, personal communication) have observed economic WCR larval damage in corn following other crops such as soybean. BARNA et al. (1998) further substantiated this loss of preference for egg laying in corn fields and noted significant adult activity in soybean fields in Indiana, USA. The egg laying that occurred in these soybean fields resulted in larval damage to the succeeding year’s corn crop. There is no relevant data available on how WCR will adapt itself to European crops, to what extent its egg laying preference might change and which crops in rotation with corn, if any, might eliminate or greatly reduce WCR population build up.

A three-year crop rotation trial was established in 2000 in Szeged in South Hungary. The crops included in the study are similar to the ones normally grown with corn in many areas of Europe. The crops rotated with corn were corn (therefore, continuous corn), sunflower, soybean and a cereal (winter wheat except in the first year, which was oat). Corn was grown on the trial field in 1999. The study field was divided into 2 sections. One part consisted of corn, while the other part consisted of 6 replications each of oat (in 2000 and wheat in subsequent years), sunflower, soybean and corn. In 2001, these two sections will be rotated so that the rotated crops in one section will be followed by corn and the corn section by the rotated crops. The presence of WCR in 2000 was assessed and quantified by using Pherocon AM traps and emergence cages (3 each per plot) from mid June to mid September. In addition, corn roots were rated for WCR larval damage and soil samples were taken to determine WCR egg populations at appropriate times during the season. Weed cover data (species and coverage) were recorded 2 times during the growing period. Preliminary results show slight WCR adult catches on Pherocon AM traps and no WCR adults in emergence cages in crops other then corn. However, relevant conclusions are not expected until the end of the 3-year study.