Pesticidi i Fitomedicina (Jan 2012)
Management of Western Corn Rootworm (Diabrotica virgifera virgifera)
Abstract
Western corn rootworm (WCR) was registered for the first time in Europe near the Surčininternational airport in Serbia in 1992. The spread of WCR on the territory of Serbia and itspopulation density increased fast. The Serbian territory was entirely populated in the followingfew years, while major damages occurred on corn grown for two or more years inthe same field. Data on damages caused to over 140,000 ha under corn until 1999 were collectedby organized monitoring. After 2000 and 2003, population abundance of D.v. virgifera,as well as the number of damaged corn fields, significantly decreased due to droughtand application of crop rotation. Corn rootworm has one generation per year. It overwintersin the egg stage. Under the climatic conditions of Serbia larvae hatching starts aroundMay 15th. The highest number of larvae on root is observed around June 20th when feedingis most intensive and plants become lodged as they lose roots. First adults emerge bythe end of June. Their abundance increases during July and reaches maximum by the endof the month. From the second decade of August the abundance decreases. Adults arepresent in the field until the first frosts. Larvae are much more harmful and significant thanadults. Larvae feed on roots or into roots by boring. Roots can be entirely destroyed underheavy attack and the host plants lodged already at the end of June. Under our climatic andagrotechnical conditions, adults are sporadic pests. Adults are a threat only when sowing isdone after the optimal sowing date or in case of stubble corn sowing.Crop rotation is an efficient and most widespread means of WCR control. No damageon corn grown in crop rotation has been registered in Serbia for now. In the first year of productioncorn does not require protection from Diabrotica virgifera virgifera LeConte larvae.Several insecticides have performed high efficacy by application at sowing and havebeen registered for commercial use. On the other hand, soil insecticides have never beenapplied on a significant area in Serbia.
