I've been getting a lot of small flies (white flies? thirps?) on many of my plants - sage, yarrow, basil, rosemary etc. When I brush my hand over the plant lots of small insects fly about. Enclosed is a picture of some of the damage. What are these? What can I do about it? Thanks Tina Grot
Howard County Maryland
Hi- a variety of sucking insect pests- four-lined plant bug, whitefly, leafhoppers, aphids, and spider mites- will feed on a variety of herb plants. Horticultural oil, neem oil, and insecticidal soap are all effective organic insecticides. But spraying damaged leaves during hot, humid weather can burn and further injure your plants.
You can cut plants back to stimulate new growth and remove heavily affected stems and foliage. Next year, covering plants with fine insect screening material (becoming more available through online gardening sources) can allow you to exclude these pests.