Upcoming Pest Events | Trap Catches | Insects | General Info

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Upcoming Pest Events | Trap Catches | Insects | General Info

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Upcoming Pest Events | Trap Catches | Insects | General Info

   After two cool and wet seasons characterized by a general lack of the normal arthropod pest problems we expect each year, the response of the current season has been an apparent return to one of those summers like we used to have.  This has been a good thing overall, but it means a return also of the typical late-season cautions regarding the last niggling pest problems that can spoil an otherwise sound management program.

   So, to be cautious, we're not ruling out the possibility that, for instance, blocks with a history of internal worm problems might need a last-minute application of a short-PHI material to help stave off the final feeding injury caused by young larvae.  Before the harvest period begins in earnest, a fruit examination could help determine whether the last brood of any of the likely species needs a final deterrent before the sprayer is put away.  Some thought might be given to using an alternative material such as a B.t., a pyrethroid, Assail, or a sprayable pheromone, as appropriate.

   Another season-end problem that may deserve attention now is this sporadic pest of pears that shows up in a limited number of commercial pear orchards and is a fairly common problem in home plantings.  The adults are very small and cannot be seen without a hand lens; the body is white and elongate oval in shape, like a tiny sausage.  The mite causes three distinct types of damage.  During winter, the feeding of the mites under the bud scales is believed to cause the bud to dry and fail to develop.  This type of damage is similar to and may be confused with bud injury from insufficient winter chilling.  Fruit damage is the most serious aspect of blister mite attack.  It occurs as a result of mites feeding on the developing pears, from the green-tip stage through bloom, causing russet spots.  These spots, which are often oval in shape, are usually depressed with a surrounding halo of clear tissue.  They are 1/4-1/2 inch in diameter and frequently run together.  A third type of injury is the blistering of leaves; blisters are 1/8-1/4 inch across and, if numerous, can blacken most of the leaf surface.  Although defoliation does not occur, leaf function can be seriously impaired by a heavy infestation.

   The mite begins overwintering as an adult beneath bud scales of fruit and leaf buds, with fruit buds preferred.  When buds start to grow in the spring, the mites attack developing fruit and emerging leaves.  This produces red blisters in which female blister mites then lay eggs.  These resulting new colonies of mites feed on the tissue within the protection of the blister, but they can move in and out through a small hole in its center.  The mites pass through several generations on the leaves but their activity slows during the warm summer months.  The red color of the blisters fades and eventually blackens.  Before leaf fall, the mites leave the blisters and migrate to the buds for the winter.

   For those plantings that might be suffering from this errant pest, a fall spray is recommended sometime in early October, when there is no danger of frost for at least 24-48 hr after the spray.  Use Sevin 50 WP (2 lb/100), or 1-1.5% oil plus either Diazinon 50WP (1 lb/100 gal) or Thiodan/Thionex 50WP (1/2-1 lb/100 gal).  A second spray of oil plus Thiodan, in the spring, just before the green tissue begins to show, will improve the control.

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Upcoming Pest Events | Trap Catches | Insects | General Info

    Please remember to make plans to attend the annual N.Y. Fruit Pest Control Field Day, which will take place during Labor Day week on Sept. 8 and 9.  This year, as we did the last 2 years in order to accommodate participants who may wish to attend other area tours earlier in the week, the Geneva installment will take place first (Thursday Sept. 8), with the Hudson Valley installment on the second day (Friday Sept. 9).  Activities will commence in Geneva on the 8th, with registration, coffee, etc., in the lobby of Barton Lab at 8:30 am.  The tour will proceed to the orchards to view plots and preliminary data from field trials involving new fungicides, miticides, and insecticides on tree fruits and grapes.  It is anticipated that the tour of field plots will be completed by noon.  On the 9th, participants will register at the Hudson Valley Laboratory starting at 8:30, after which we will view and discuss results from field trials on apples.

Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to:

Scaffolds Fruit Journal
Editors: A. Agnello, D. Kain
Dept. of Entomology, NYSAES
P.O. Box 462
Geneva, NY 14456-0462
Phone: 315-787-2341 FAX: 315-787-2326
E-mail: ama4@cornell.edu

Online at <http://www.nysaes.cornell.edu/ent/scaffolds/>