Pest Activity -- April 21, 2000

Pest Activity > Pest Activity Archives > April 21, 2000

Welcome to the Woody Ornamental Pest Scouting Report for Western Pennsylvania for April 21, 2000, brought to you by Penn State Cooperative Extension. 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 April 19, the following growing degree days using a base temperature of 50 degrees have accumulated:

Fox Chapel	147
Butler	110
Uniontown	186
New Stanton	141

Boxwood Psyllid nymphs were observed this past week in the City of Pittsburgh. The feeding activity of this pest causes the cupping of the terminal leaves on boxwoods and treatment should be applied now before the nymphs become adults.

If Diplodia Tip Blight was a problem for you on these pines last year, fungicide applications should begin at bud break and repeated on a 10-14 day interval until the needles reach full size. The candles on Austrian and Mugho pines in the city of Pittsburgh are expanding and new leaf emergence should occur in the next two weeks.

Pine Spittlebug nymphs were observed this past week on white and Scotch pines in Westmoreland County. Unless heavy infestations occur, this pest rarely warrants the use of insecticides. If you do experience a heavy infestation, the control should be targeted at the adult spittlebugs, which are present in early July.

Spruce Spider Mites are active on spruce, junipers, arborvitae and other conifers. To check for the presence of this mite simply shake the branch of the spruce tree while holding a white piece of paper underneath to catch the mites. If you have a mite infestation, you will see small reddish dots moving on the paper.

Conspicuous by their absence this year is the Eastern Tent Caterpillar. While there are sufficient growing degree days for their emergence, I have been unable to find any larvae or overwintering egg masses at the sites I am scouting.

The terminal growth of Scotch, Japanese Red and Mugho Pines should be inspected at this time for the dark green, black headed larvae of the European Pine Sawfly. Control measures at this time include physical removal or a spot treatment with a pesticide labeled for control of this pest.

Immature adults of Cooley Spruce Gall Adelgids observed on Douglas Fir in Westmoreland County this week again only showed white waxy thread around the perimeter of their bodies. Once the wax completely covers their entire body, the early season window for control is closed. It is important to check for this protective covering prior to applying a control measure.

White Pine Weevil feeding on terminals of Eastern White Pine was spotted again in Westmoreland and Beaver counties this past week but no egg laying has been observed to date. The terminals should be inspected for egg laying prior to applying an insecticide since control efficacy is greatly reduced once the eggs are laid and covered with pine pitch.

Eriophyid mites continue to be active on hemlocks in Westmoreland and Beaver counties. Registered insecticides applied according to label directions should be used at this time.

Crabapples that are highly susceptible to apple scab can be sprayed at this time. Recent research indicates that a combination of the fungicides Banner and Daconil provides very good control of apple scab when applying either 3 sprays at two week intervals or 2 sprays at 3 week intervals. Initial sprays for apple scab on crabapples should be applied now. If you are considering a crabapple for a new installation, please call the extension office at 412-473-2540 for a list of disease resistant crabapples or we can be reached via e-mail at AlleghenyExt@psu.edu.

The next page update will be on Friday, April 28th.