KOMÁROMI, Judith¹; EDWARDS, C. Richard²; KISS, Jozsef^1
1 Szent István University, Department of Plant Protection, Gödöllõ, Hungary,
² Department of Entomology, Purdue University, IN, USA

The spread of WCR over Europe has been determined through the use of various trap types (Csalomon pheromone trap, yellow sticky traps like Multigard® and Pherocon AM®). Once the pest has established itself within an area, its population built up should be followed and economic threshold values must be established. Most often, Csalomon pheromone and Multigard yellow sticky traps have been used for monitoring WCR adults, and also for measuring the population built up in Europe. Within fields, emergence cages can be used to gauge the appearance of WCR adults from the soil over time. Comparison of data from relative and absolute sampling methods may be useful indicators for population build up over a period of time from first appearance to populations at economic levels.

In the Bacska Region study, data from Csalomon pheromone and Multigard yellow sticky traps (relative sampling methods), as well as data from emergence cages (absolute sampling method) were compared. During the summer of 1998, 1999, and 2000, experiments were carried out in this region, in the area of Subotica, Palics, Pacsér and Moravica close to the Hungarian border. Traps were placed in 6 corn fields in the first two years of the study and 3 in the third year. Four Csalomon traps, 8 Multigard traps, and 4 emergence cages were placed within each of the fields, which ranged in size from 1-2 hectares. Corn had been grown in all these fields before. Traps were operated from late June, early July to the middle of September each year. Traps were changed weekly in all three years. The maximum number of WCR beetles (as an average of 6 fields) in the various traps was as follows*:
 

	1998	1999
Emergence cages	1 adult/trap/week	1 adult/trap/week
Multigard traps	10 adults/trap/week	68 adults/trap/week
Csalomon pheromone traps	54 adults/trap/week	218 adults/trap/week

*Data for the 2000 sampling-period will be presented in the talk.

Adult appearance, trapping data for the various traps, and field-level analysis of data over the three-year study will be discussed in detail at the meeting.