Ornamentals
Spruce Spider mites have NOT been found yet on plots in Floyd County but their activity should pick up soon in this area. Generally they start feeding in late April and early May. Scout by picking off a small branch at the base of the conifer shrub. Look for actual mites, as the damage will remain from last year. Treat with insecticidal soap, Joust (used to be called Morestan), or Kelthane.
Fall cankerworm (also called inchworms) are suspended from the oaks and many other shade trees at AREC by silken strands. Being at eye level they can be very noticeable. They are much worse than usual this year in the Virginia Beach area, probably the worst since 1982. The ragged looks of the new leaves on other trees and shrubs are the result of their feeding. Regrettably the ragged foliage remains as a reminder until the leaves drop in the fall. Insecticidal treatment may be recommended should the trees be totally defoliated and in sensitive locations (regarding the frass and suspended larvae).
Boxwood leaf miner adults are being collected in large numbers from traps in infested boxwoods. For heavy infestations: Adult leafminer flies emerge over a two-week period in early spring after the boxwoods have put out their growth. These flies resemble tiny, orange mosquitoes (about 1/4 inch long) which swarm around or cling, to boxwoods. After laying eggs in the leaf tissue, the flies die. Now is the time to apply treatments directed at the adults.
Southern red mite populations persist on the many broad-leaf evergreens they frequent. Attention should be paid to the presence of live mites, and the need to apply control measures. The PMG offers a number of possible miticides registered.
Ash/lilac borers are being collected in pheromone traps. A bark treatment is recommended for trees with this borer 10 days after 1st emergence. That has passed in the warmer regions of coastal Virginia, but a treatment would still be effective.
Soft scales are becoming noticeable on shrubs and shade trees. Lecanium scale on oaks, calico scale on honeylocust, and Pulvinaria scale on camellias have all been observed in high numbers. Their honeydew excretions result in sooty mold formation on foliage. The deposits are equally unwelcome on car exteriors. Horticultural oil is one option, with additional pesticides recommended in the PMG.
Aphids are appearing in large numbers on several ornamental species. Distorted foliage is a common symptom. River birch foliage turns reddish from aphid feeding. Aphids prefer the newest growth. Insecticidal soap is one option; where residual activity is required, acephate (Orthene) is one of many choices.
Peter B. Schultz, Director
Hampton Roads AREC
1444 Diamond Springs Road
Virginia Beach, VA 23455
(757) 363-3907, fax (757) 363-3950
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