INDEX | NEXT | PREVIOUS

13. Preliminary Assessment of Effect of Prescribed Fire upon Establishment of Aphthona nigriscutis in Leafy Spurge.  David P. Fellows and Wesley E. Newton, National Biological Service, Northern Prairie Science Center, 8711 37th St. SE, Jamestown, ND 58401

Preliminary data from A. nigriscutis release sites on 5 Waterfowl Production Areas (WPA's) in South Central ND suggest that prescribed burning in the fall or spring preceding release of the beetles may increase the chances of successful colonization. One hundred and fifty beetles were released on each of 10 sites/WPA in June 1994. Of the 10 sites on each WPA, 2 had been burned in October 1993 and 2 had been burned in early May, 1994. In June, 1995, beetles were recovered in sweep net samples on 90% of the fall-burn sites and 80% of the spring-burn sites, compared to only 34% of the unburned sites; the proportion of sites where beetles were recovered was significantly greater among burned than unburned sites (P<0.01). Taking all release sites into consideration, significantly more beetles were captured on the burned (x="12.4/fall" burned site and x="13.3/spring" burned site) sites than on the unburned sites x="2.6" beetles/site) (P< 0.01). Considering only those sites where beetles were captured, the mean number of captures tended to be higher on the burned (x="13.8" fall, x="16.6" spring) than on the unburned (x="6.7)" sites, but the difference was not significant (P="0.53).<p">

INDEX | NEXT | PREVIOUS