Pest Activity -- May 4, 2001

Pest Activity > Pest Activity Archives > May 4, 2001

Welcome to the Woody Ornamental Pest Scouting Report for Western Pennsylvania for May 4, 2001, brought to you by Penn State Cooperative Extension and the PA IPM Program.This tape will be updated weekly with growing degree day counts and insect activity through the end of June. If you would like an email copy of this report, send your request to mcm2@psu.edu.

As of May 2, the following growing degree days using a base temperature of 50 degrees have accumulated:

Wexford	190
Uniontown	331
New Stanton	220
Butler	146

Pine Needle Scale crawlers were on the move in the city of Pittsburgh and in Westmoreland county this past week, while crawlers observed in Sewickley were still beneath the protective scale cover. Now is the time to check the needles of Mugo, Scotch, Red and Austrian pines for tiny red crawlers migrating from beneath the scale covering to a new site. Two applications of a pesticide are recommended if you are trying to control a heavy infestation of this scale insect.

Birch leafminer larvae were observed in Allegheny County this week. There are several generations per year of this leafmining sawfly, but only the first generation warrant control. If mines are present, a systemic insecticide should be used to kill the developing larvae.

Now is the time to check for Spruce spider mite activity on conifers. Some of their preferred hosts are spruce, arborvitae, junipers, hemlocks, and Douglas-fir.

Inkberry leafminer, adults were observed in Westmoreland County and control sprays should be applied at this time. This is a key pest of Ilex glabra or inkberry holly with two generations per year occurring in western Pennsylvania. The second generation occurs from mid-August to mid September.

Boxwood Psyllid nymphs continue to feed on the new growth of boxwoods causing the cupping of the terminal leaves. Treatment should be applied now before the nymphs become adults.

White Pine Weevil eggs were observed in Westmoreland County again this past week, thus closing out the window for control of this pest for many parts of southwest Pennsylvania. This pest is responsible for killing the terminal leader on Eastern White Pine, Spruces, and occasionally Douglas Fir.

Eastern Tent Caterpillar populations in many parts of southwest Pennsylvania are more prevalent than the past few years. Larvae in Westmoreland County measured 3/4 to 1 inch long.

European Pine Sawfly larvae in Westmoreland county are 3/8 to 1/2 inch long and continue to feed on last year's terminal growth. Their preferred host plants are Scotch, Japanese Red and Mugo Pines. At this time the larvae are confined to a localized area and a spot treatment or physical removal will provide control.

Eriophyid mites continue to feed on hemlocks in southwest Pennsylvania at this time.

Sphaeropsis Tip Blight -- Photo courtesy of Michael Masiuk

The candles on Austrian and Mugo pines are expanding, which is the ideal time to apply the first spray to control Sphaeropsis Tip Blight. (formerly Diplodia) If this disease was a serious problem last year, fungicide applications should be applied on a 10-14 day interval until the needles reach full size.

 

 

The next tape update will be on Friday, May 11th.