The following are pests you should be on the watch for now in Delaware landscapes.
Clearwing borer populations (Lilac/Ash, Dogwood, and others) are prevalent. Protect trees as needed with pyrethroids like permethrin or bifenthrin.
Watch for building whitefly populations on annuals and select perennials. Parasites may move in and turn the normally yellowish nymphs black or other management strategies may be required.
The USDA has initiated a citizen survey for the Asian longhorned beetle (not yet ID’d in DE). Interested persons may receive a letter and identification sheet, along with a card to return to report findings. Call the PLSC office (302-831-2534) for materials.
Japanese maple scales have been found in egg & crawler stage in Kent County.
Puss caterpillars were found feeding on Ilex & Acer. This caterpillar has a nasty sting associated with its hairs, so be careful moving plant material. Feeding damage is not severe on plants so treatment is not often warranted.
Tuliptree & magnolia scale crawlers are approaching peak crawler activity. Horticultural oil, Insecticidal soap, Distance are good products for crawler control.
Information from the "What's Hot" section of the Ornamentals Hotline Newsletter from the UD Cooperative Extension Ornamentals Group.