Ilie VONICA
Central Laboratory for Phytosanitary Quarantine, Bucharest - Romania

Introduction: Field monitoring of Diabrotica populations within Romanian territory has been started, in organized way, within the framework of IWGO/OEPP using „Curcurbitacin“ traps in 1995 and „Cucurbitacin“ and Multigard yellow sticky traps in 1996. During 1997-2000 years this activity has continued within the framework of FAO TCP/RER/6712 „Development and implementation of containment of the Western Corn Rootworm in Europe“ project using pheromone and Multigard traps.

Results
The dissemination of WCR within Romanian territory is indicated on the attached map. In 1996, three adults were captured on a Multigard trap in Arad county, Nadlac locality, near the border with Hungary. During the following years, WCR infested soon new counties such as: Caras-Severin, Timis, Arad and Mehedinti in 1997; Bihor and Hunedoara in 1998; Dolj in 1999 and Satu Mare, Salaj, Alba, Gorj and Olt in 2000, twelve counties in total.

The populations of Diabrotica have increased strongly, year by year, reaching their maximum level in 2000 year, especially in Caras-Severin, Timis, Arad, Mehedinti county. The average number of captured adults on one installed trap have increased from 105 in 1997 (with the extremes 5.6 in Mehedinti and 391 in Caras-Severin) to 612.1 in 2000 (with the extremes 150.5 in Mehedinti and 904.4 in Caras-Severin) and on trap with captures from 181 in 1997 (with extremes 13.6 in Mehedinti and 503.4 in Carsa-Severin) to 654.3 in 2000 (with extremes 207 in Mehedinti and 904.4 in Caras-Severin).

Larval damage to roots was noted in 1999, on maize monoculture in Caras-Severin county (Campia/Socol and Oravita). This damage however was not at economic levels. The first cases of economic damage on maize monocultures were registered in the same localities, in 2000. Because of the high temperatures during the spring of 2000 year the first adults appeared approximately three weeks earlier than in normal years, respectively in the first ten days of June.