Boxwood Leafminer

Boxwood leafminer adults will be emerging any day. The maggots can do significant damage to the appearance of boxwood, but they usually do not cause dieback. Because the boxwood leafminer has only one generation of midges per year, treating in April and May with a systemic insecticide may prevent premature plant defoliation. Another application should probably be made in mid to late February of the following spring. The maggots develop in blister-like galls on the current year's leaves. Heavily-infested shrubs may become discolored particularly during the winter. These shrubs also tend to defoliate prematurely. In our demonstrations, Orthene and Merit have both given good control of this leafminer when injected into the soil or applied as a drench. Orthene 9.4% emulsifiable concentrate is actually labeled for leafminers on shrubs. Merit is labeled for leafminers on ornamentals and now being marketed in several homeowner products. Ornamentals and Turf Insect Note No. 16 (http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/ort016e/ort016e.htm) provides information on the biology and control of the boxwood leafminer.

From: Steve Bambara, Extension Entomologist

Tent Caterpillars on the Prowl

All areas of the state should be in some stage of tent caterpillar activity. They have been active in eastern counties for several weeks. In the Piedmont they seem to be in the crawling/dispersing phase. Personal observation is that there are many fewer webs this spring than in years past. These hairy caterpillars can make a cherry or crabapple tree look a little ugly, but most trees seem to recover and re-foliate. Unless trees are taller than 15 feet or you have dozens to deal with, a long stick or pole can be used to destroy the web masses quite effectively. Resist the temptation to burn them! See Ornamentals and Turf Insect Note No. 61 (http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note61/note61.html) for more information.

From: Steve Bambara, Extension Entomologist