AUTUMN PEST REVIEW: Although the season is beginning to wind-down, there are still a number of insect & mite pests that require scouting during the fall weeks. The pests discussed in this blog include soft scale nymphs, boxwood leafminers, white pine aphids, spruce spider mites, southern red spider mites, hemlock rust mites, eastern spruce gall adelgids & hemlock woolly adelgids. The use of low %-rates of horticultural oils this fall can be especially valuable against controlling many of these pests.
SOFT SCALE NYMPH MIGRATIONS: Most soft scale species (exceptions include magnolia, tuliptree, and globose) have 1st instar nymphs that spend July and August feeding along veins on the undersides of leaves of their deciduous host (the use of a hand lens may be needed). During the weeks of late summer and early fall, these nymphs migrate off the leaves onto woody stem tissue and molt into the overwintering 2nd instar stage. The size of the nymphs increases 3-times after molting and their presence is usually observable even without magnification (they can be as large as lenticels). Typically, overwintering soft-scale nymphs have a dark coloration, to help absorb sunlight and maintain body warmth.
European elm 1st-instar nymphs settled along the main vein underneath elm leaf. During the early weeks of fall they migrate from leaves onto the bark to overwinter. (Photo Credit: Cornell University)
Multiple Northeast SARE (Sustainable Agriculture Research and Education) grant recipient Tommye Lou Rafes, of T.L. Fruits and Vegetables in West Virginia, is sharing her experiences to help other farmers experiment with new ideas through the Farmer Grant program.
