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Jack pine budworm

Initial ground surveys in early June indicated that the jack pine budworm remains at low levels in central and northwestern Minnesota. This pest was found as second instar caterpillars (1/16 inch long) in very low numbers feeding in the pollen cones. A more extensive survey will be completed in late June, and at each survey site six shoots and/or pollen cone clusters on each of five trees will be checked for budworms. If 20 or more budworms are found on the 30 shoots and pollen cone clusters, moderate to heavy defoliation can result. During the early June initial surveys the most budworms found at any site was two.

Early larval surveys were started during the week of June 9th in Region I. Plots were taken in the southern parts of Hubbard and Becker Counties that border Wadena County. Jack pine stands that experienced moderate to heavy defoliation in 1994 were sampled first. So far sampling is averaging 0.5 larvae per 30 shoots with the commonest number being zero. JPBW populations collapsed in 1996. Survey results so far in 1997 confirm this analysis also.