From Marc.Safley@usda.gov Fri Aug 20 17:57:39 1999 Date: Fri, 20 Aug 1999 12:49:00 -0400 From: Marc Safley To: Receipt Notification Requested Subject: Landscape Structure and Biological Control There is a research article of interest in the August 6th edition of 'Science' that should be of interest to those on this list. It is entitled "Landscape Structure and Biological Control in Agroecosystems" and was written by Carsten Thies and Teja Tscharntke, Department of Agroecology, University of Goettingen, Germany. Following is the abstract: "Biological pest control has primarily relied on local improvements in populations of natural enemies, but landscape structure may also be important. This is shown here with experiments at different spatial scales using the rape pollen beetle (Meligethes aeneus), an important pest on oilseed rape (Brassica napus). The presence of old field margin strips along rape fields was asociated with increased mortality of pollen beetles resulting from parasitism and adjacent, large, old fallow habitats had an even greater effect. In structurally complex landscapes, parasitism was higher and crop damage was lower than in simple landscapes with a high percentage of agricultural use." Marc Safley Agricultural Ecologist NRCS/USDA marc.safley@usda.gov To Unsubscribe: Email majordomo@ces.ncsu.edu with the command "unsubscribe sanet-mg". If you receive the digest format, use the command "unsubscribe sanet-mg-digest". To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command "subscribe sanet-mg-digest". All messages to sanet-mg are archived at: http://www.sare.org/san/htdocs/hypermail