Western corn rootworm adult movement and possible egg laying in fields bordering maize

Abstract

Western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, larval damage in maize following soybean was observed in Croatia in 2003 along the edges and within soybean fields which bordered continuous maize fields in previous year. The explanation was that WCR adults moved from the continuous maize to the neighbouring soybean fields to lay eggs. This study was designed to measure how far WCR adults will enter into neighbouring fields to lay eggs. The WCR adult population was monitored in continuous maize fields in 2003 and 2005 by using Pherocon Ò AM non-baited yellow sticky traps in the middle and on the borders of the maize field and at different distances and directions into neighbouring fields planted by wheat and soybean. Larval presence and root damage ratings (Iowa State University 1-6 ) were recorded at different locations within the maize field in following years. Approximately, the same concentration of WCR adults was recorded along the edges of the maize fields as recorded in the centres of those fields. A significant number of WCR adults was recorded up to a distance of 50 m into neighbouring fields. Regression analysis showed medium negative correlation between distance from previous maize field and root damage in the following year. Findings indicate that WCR egg lying can reach approximately 20 m into fields neighbouring maize fields and that significant root damage caused by WCR larvae in first-year maize following soybean and wheat can happen up to a distance of 20 m into those fields. Most farmers's fields in Croatia are up to approximately 50 m wide. As an edge effect for WCR egg laying can reach approximately 20 m into fields neighbouring maize fields, our research results indicate that it is possible to see WCR larval damage in rotated fields without those WCR's being the variant form.

Estimating Diabrotica virgifera virgifera damage functions with field trial data: applying an unbalanced nested error component model

“…2009). A major concern is that the western corn rootworm population in Europe will also develop resistance to control methods or that an introduction from North America has or will introduce resistance genes or the soybean variant into current European populations (Igrc Barcic et al. 2007; Ciosi et al.…”

Adaptation and Invasiveness of Western Corn Rootworm: Intensifying Research on a Worsening Pest

“…They suggested that knowledge gained from a more landscape-focused approach rather than a fieldby-field basis would be helpful in improving the management of western corn rootworms. IgrcBarcic et al (34) found western corn rootworm adults in neighboring fields up to 50 m from maize field margins. This dispersal into adjacent nonmaize crops resulted in egg laying and subsequent larval damage in rotated maize the following season up to 20 m from the field border.…”

Adult activity and oviposition of corn rootworms, Diabrotica spp. (Coleoptera: Chrysomelidae), in Miscanthus, corn and switchgrass

“…Similarly, work by Igrc Barčić et al. () in Croatia found evidence that D. v. virgifera with normal oviposition preference for corn still may lay eggs as much as 20 m into soybean and wheat fields, capable of producing significant root damage when corn is subsequently planted. When the outer edges of plots are disregarded, 3–10 times the adult D. v. virgifera were trapped in corn as in Miscanthus or switchgrass and females laid approximately 10 times as many eggs in corn.…”