A. M. Wellwood1, G. Nickerson1 and J. Wetmore2
Partner: New Brunswick Horticultural Trades Association
Abstract: Hairy chinch bug, Blissus leucopterus hirtus, populations were surveyed in 5 regions of New Brunswick (Bathurst, Grand Falls, Moncton, Fredericton, and Rothesay) in 2002 to establish monitoring, threshold and treatment guidelines. A total of 23 chinch-infested lawns were monitored. Floatation and quadrat monitoring techniques were compared. Monitoring was done weekly for 12 weeks (June to August) in all locations and continued for an additional 9 weeks at 2 locations to observe 2nd generation insect development. The quadrat monitoring method was as effective as the floatation method for guiding insect control decisions. The quadrat treatment threshold was established at 10 chinch bugs per 0.1m2 for a 60 to 90-second search, while the 10-minute floatation threshold was set at 27 to 38 chinch bugs per 0.1m2 (between 9 and 12 in an 8-inch diameter can). Treatments for chinch bug should be applied at the peak of the combined 2nd and 3rd instar populations. In 2002 the combined populations peaked in Bathurst, Grand Falls, Fredericton, Moncton, and Rothesay between 427 and 877 degree-days (7ºC base, air temperature). This indicates an optimum treatment window for hairy chinch bug between mid-July and mid-August in New Brunswick. Pest control intervention is not always necessary for above threshold populations of chinch bug. Treatment decisions must also consider the health of the lawn, history of previous insect damage, soil depth and quality, excessive thatch levels, plant species mix (grass and broadleaf), and general turf maintenance practices (fertility, mowing height/frequency). It was found that lawns with high populations of broadleaf weeds (greater or equal 30%) and acceptable visual appearance, showed less visible damage from chinch bug feeding even with chinch bug populations that were well above treatment threshold levels.
1 NB Department of Agriculture, Fisheries and Aquaculture, Agriculture Development Branch, P.O. Box 6000, Fredericton, NB, E3B 5H1
2 Wetmore's Landscaping, 3708 Highway 102, Islandview, NB, E3E 1G3