Pest Activity -- Woody Ornamental Integrated Pest Management at Penn State

Pest Activity -- April 13 , 2007

Welcome to the Woody Ornamental Pest Scouting Report for Western Pennsylvania brought to you by Penn State Cooperative Extension. This report is 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 11, the following growing degree days with a base temperature of 50 degrees have accumulated.

Uniontown	142
Pittsburgh	130
Wexford	113
Butler	112

Pest Activity

Cooley Spruce Gall

Overwintering Cooley Spruce Gall Adelgids continue to produce the white waxy strands. Depending upon your location, there may still be time to apply a control for this pest. The insecticide needs to be applied, before they are completely protected by the white waxy excretions as shown in the image to the left. The list of currently labeled insecticides for use in Pennsylvania on Douglas -fir can be found here.

Fact Sheet

Eastern Tent Caterpillar

Eastern Tent Caterpillar eggs have hatched in much of SW Pennsylvania. In my travels this week, I have not seen a lot of of this pest, but based on past history, the minute I make that statement they show up evereywhere. Physical removal of the egg masses and tiny larvae is the easiest control method when they can reached from the ground.
Eastern tent caterpillar's primary host plants are wild cherry (Prunus pensylvanica), apple (Malus) and crabapple (Malus). Occasionally, they feed on deciduous forest and ornamental trees such as ash (Fraxinus), birch (Betula), blackgum (Nyssa sylvatica), willow (Salix), witchhazel (Hamamelis), maple (Acer), oak (Quercus), poplar (Populus), peach (Prunus), and plum (Prunus).

Fact Sheet

Hemlock Rust Mite

Hemlock Rust Mite remain active in SW Pennsylvania at this time. This is the time that controls should be applied.

Click here for current list of insecticides labeled for use in Pennsylvania.

Fact Sheet

Spruce Spider Mites

	Unhatched eggs of the Spruce Spider Mite were found on Hemlocks in the City of Pittsburgh on Wednesday.The short term forecast is for cooler than normal temperatures, so egg hatch may be delayed.
Fact Sheet

White Vine Weevil

Signs of adult white pine weevil feeding on the terminal leaders of an eastern white pine, were observed in the city of Pittsburgh this week, but there is no sign of egg laying. Now is the time to apply insecticidal sprays to the tops of white pines for control of this pest.

Click here for current list of insecticides labeled for use in Pennsylvania.

Fact Sheet

OTHER PESTS

Bittercress

Seedpods are forming at this time, so hand-weeding is the best option.

Frost/Freeze Damage

Tissue damage from the extremely cold temperatures we experienced last week is showing up on a wide variety of plants. I observed "burnt leaves" on Burkwood Viburnum (shown at left), Japanese Tree Lilac and Katsuratree in the City of Pittsburgh and the Sewickley area.

Winter injury to many broad leaf evergreens and some hemlocks continues to generate inquiries this past week.

Apple Scab

This foliar disease which is responsible for early defoliation of susceptible crabs can be avoided by growing resistant cultivars
Scab-resistant crabapples: Adams, Baskatong, Brandywine, Callaway, David, Dolgo, Donald Wyman, Malus floribunda, Henry Kohankie, Henningi, Jewelberry, Ormiston Roy, Professor Sprenger, Malus seiboldi var. zum cultivar Calocarpa, Silver Moon, Sugartyme, Malus tschonoski, Weeping Candy Apple, White Angel, and White Cascade have been observed in many locations to have only slight to moderate scab infections.

If you are respoponsible for maintaining a crab that is susceptible, research has shown excellent control by applying propiconazole + chlorothalonil as flower buds begin to show color (early pink) and again 3 weeks later.

The next scouting report will be on April 20, 2007 .