Pest Activity -- June 6, 2000

Pest Activity > Pest Activity Archives > June 6, 2000

Welcome to the Woody Ornamental Pest Scouting Report for Western Pennsylvania for June 6, 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 May 31, the following growing degree days using a base temperature of 50 degrees have accumulated:

Fox Chapel	577
Butler	284
Uniontown	660
New Stanton	558

Rhododendron Lacebug nymphs are active in many counties in SW Pennsylvania. It is beneficial to prevent lacebug damage on broadleaf evergreens such as Azaleas, Rhododendron, Pieris, Mt. Laurel and Pyracantha early in the season because these plants will retain the unattractive foliage through more than one growing season.

The relatively cool temperatures have resulted in Spruce Spider Mites remaining active on spruce, junipers, arborvitae and other conifers.

Hemlock Rust Mites also continue to be active on hemlocks in Westmoreland county. Registered insecticides applied according to label directions should be used at this time if mites are present.

Euonymus Scale eggs have hatched and crawlers were observed in the city of Pittsburgh this past week. Some of their common hosts plants include boxwoods, English Ivy, privet and pachysandra and Euonymus fortunei. Multiple pesticide applications may be required to control this pest so be sure to examine plants to evaluate the effectiveness of your control measures.

Bagworms have hatched and the larvae are actively feeding and forming bags on a wide variety of both conifers and deciduous trees. The damage to conifers is more serious since they can be defoliated and this can kill them in one season because they are not able to set out new foliage later in the season like deciduous trees. Due to their camouflage technique of covering themselves with small pieces of foliage, close inspection is required to detect their presence in their early stage. If they are no larger than 3/8 inch, you can easily kill the larvae with a Bacillus thuringiensis or (BT) spray. Larger larvae will require the use of a more traditional insecticide.