Marija IVEZIC1, Jon J. TOLLEFSON2,
Emilija RASPUDIC1, Drazen DZOIC3
1 Univ. of J.J. Strossmayer
in Osijek, Faculty of Agriculture, Dep. Of Plant Protection, POB 719 31000
Osijek, Croatia
2 Iowa State Univ., Dep. Of
Entomology, Ames, Iowa 50011-3140, USA
3 Ministry of Agriculture and
Forestry, Ul. Grada Vukovara 78, 10000 Zagreb, Croatia
In 1995 the corn rootworm (Diabrotica virgifera virgifera LeConte) was detected for the first time in East Slavonia, Croatia. Its expansion to the west has been very fast and from year to year populations of the pest are higher, especially when corn is planted after corn. The aim of this investigation was to find the best trap for monitoring Diabrotica. The studies were conducted using three types of traps: the USA Trece lure trap, Multigard yellow sticky trap and Hungarian pheromone trap. The treatments were replicated four times in a maize field located at the east of Croatia, very near to the border of Yugoslavia. The traps were placed in the field on the 23rd of June and the experiment continued until the 15th of September. Pheromone and Multigard sticky traps were replaced with new ones each month. Traps were positioned 60 m apart within a row and 70 m apart across maize rows. Silking occurred from 30 June to 8 August (exposed silk thoroughly brown and dry). This year was extremely dry and the first beetles were noticed on the 15th of June. This was 20 days earlier then in 1999. Adult rootworm beetles were removed from the traps one weekly. Pheromone traps captured the most beetles (2263), Multigard sticky traps caught the second most (214) and lure traps the fewest (182) for whole period. After the replacement of pheromone and Multigard traps, the capture of beetles increased. Of the total number of beetles caught, 85,10 % were caught by the pheromone traps, 8,05 % by the Multigard sticky traps and 6,85 % by the lure traps. Because this year was so dry (50 % less rainfall than the 20 year average), the investigation should be continued in the future to get more precise results.