Euonymus scale control May 15 to 20

Euonymus scale can be very prolific and nearly cover plants if left unchecked. Based on current growing degree day accumulations we should see the crawler stage in the next two weeks around May 15-20. All scale insects are most susceptible to insecticides during this stage when they are unprotected from the hard covering that protects them during most of the year. Information can be found in the Euonymus Scale Factsheet. Control can be found in Bulletin 504 Table 2 Ornamental Pest page 9.

Gypsy Moth should be sprayed in next 7-10 days

Gypsy Moth larvae are hatching and will be in there most susceptible stage in the next week. The small larvae are most susceptible. Aeriel applications in suppression areas targeted by Ohio Department of Agriculture are being sprayed at this time. If you have trees with egg masses you will want to spray soon. Insecticides can be found in Bulletin 504 Table 1 General Pest page 7. For more information on Gypsy Moth see the following factsheet http://ohioline.osu.edu/hyg-fact/2000/2173.html

Time to Control Pine Needle Scale

Pine needle scale is very common on Mugo Pines but can be on a variety of other species. Based on accumulated Growing Degrees days the crawler stage should be out shortly. This is the stage where insecticides are most effective. More information on needle scale can be found in Pine Needle Scale. Insecticides for control can be found in Bulletin 504 Table 1 General Pest and page 14 of the pdf.

Black Knot on Prunus Species

A couple of samples brought in during the past week had a thickened black stem on the branches. This is a common occurrence on Prunus sp. which include cherry and plum. There areornamental type of these plants which are also susceptible. Control include prune out the branches and using fungicides. A furthur description and other details can be found in Black Knot of Plum and Cherries.