In this Issue:
- Earwigs: Friend or Foe?
- Cabbage Aphids: Damaging your brassicas
- Watermelon Mosaic Virus: Watch your melons
Earwigs (Forficula auricularia)
The European earwig is a menacing invasive species that is both a pest to some host crops and beneficial insect to others. The adults are slender with a brown body, red-brown head, and have a prominent pair of “pinchers” on the rear of its body. The earwigs feed on beans, beets, cabbage, cauliflower, celery, chard, corn, cucurbits, leafy greens, potatoes, tomatoes, flowers, and consume pests such as aphids.
Both earwig nymphs and adults will crawl into tight, dark places during the day. They can feed on the buds, flowers, fruits, corn silks, and young vegetable seedlings that can cause direct plant damage.
Populations are at their highest from mid to late summer. Monitor by placing boards, crumpled moist newspaper, or corrugated cardboard on the ground near host plants. Management is only really necessary when populations are causing unacceptable crop damage.
Cabbage Aphids (Brevicoryne brassicaell)
Adult cabbage aphids are usually 2-2.5 mm long and range from a green to grey color. They have a significant waxy covering and short cornicles. Cabbage aphids primarily feed on broccoli, Brussel sprouts, cabbage, and cauliflower.
When not controlled, Cabbage Aphids populations can become very dense. These masses can lead to honeydew and sooty mold on the plants. The host plant leaves will wrinkle, curly, and cup downward.
– Manage nitrogen levels; avoid excess.
– Encourage natural enemies; avoid toxic chemicals, provide nectar and pollen resources.
– Keep crop area weed-free.
– For viruses transmitted by aphids: plant resistant cultivars, plant early, and removed infected plants.
– Click here to view commercial use insecticide options
– Click here to view home use insecticide options
Watermelon Mosaic Virus
Watermelon Mosaic Virus is a Potyvirus transmitted by aphids. It can affect beans, cucumbers, gourds, peas, pumpkins, squashes, watermelons, and various weed species. The symptoms can include stunting, leaf malformation, yellowing mottling, marginal chlorosis, and fruit deformation. This disease can be widespread in Utah watermelon production along with cantaloupe.
– Control Weeds
– Rotate crops
– Use resistant varieties when available
– Insecticides for aphids are of limited value to control this disease