An early spring changes a fall defoliator into a summer defoliator
Over 95% of the orange-striped oakworms in central Minnesota completed their leaf feeding by mid-August. This forest insect can sometimes be found in great numbers in mid-September, but our early and warm spring weather allowed them to emerge a month earlier. More parasites of the eggs and pupae were observed this August, and more evidence of squirrels scratching the duff for pupae to eat was evident, also. Overall, defoliation in l998 was much less than that of l997 in most areas where this insect had localized outbreaks last year.
to include a review of the role of insect and disease management in forest
The upcoming Forest Productivity Conference in Duluth this December will reassert that pest management actions are a critical portion of any logistical plan to improve forest productivity for timber. History documents the impact of insect and disease agents on fiber and wood product availability. Data from the 1990 Forest Inventory and Analysis for Minnesota indicates that 37% of the wood volume produced by all species annually, dies due to natural causes. Insect and disease agents account for 53% of this loss or over 117,000,000 cubic feet of wood. Currently, Minnesota reports active infestations of oak wilt, spruce budworm, forest tent caterpillar and bark beetles. Exotics, such as the gypsy moth and Asian long horned beetle, are in our future. Forest managers need to be familiar with several key integrated pest management concepts to successfully limit losses in intensively managed stands. They include: proper site selection and preparation, host vigor, diversity, resistance vs. immunity, crop protection vs. salvage, the impact of exotics, economic threshold and direct vs. indirect control. Come to the conference ready to discuss these topics in relation to today's markets, harvesting technologies and environmental concerns. See you there!