How to get rid of psyllids (psyllids)

There are over 100 species of leaflets found throughout North America. Here's how to identify them and get rid of them using proven, natural and organic treatments.

Leaf lice, sometimes called jumping plant lice, feed on a variety of plants, including most fruit trees and small fruits, as well as tomatoes and potatoes. Both adults and nymphs feed by piercing the surface of the leaf and extracting cell sap. This causes the foliage (especially the upper leaves) to yellow, curl, and eventually die. Honeydew released from foliage encourages the growth of dark, sooty molds. Many species carry viruses that transmit disease.

Identification

Adults (1/10 inch long) are reddish-brown in color, with transparent wings and strong hopping legs. They are very active and will jump or fly away if disturbed. The nymphs are flat and elliptical in shape, almost scaly. They are less active than adults and are most numerous on the undersides of leaves. Newly hatched nymphs are yellowish in color, but turn green as they mature.

Note: Leaflids are monophagous, meaning they are host specific (each species feeds on only one type of plant).

Life cycle

Adults overwinter in crevices of tree trunks. In early spring they mate and the females begin laying orange-yellow eggs in crevices around the buds and on the leaves once the foliage opens. Hatching occurs after 4-15 days. Yellow-green nymphs go through five instars in 2-3 weeks before reaching the adult stage. Depending on the species, there are from one to five generations per year.

How to control

1. Spray horticultural oil in early spring to kill overwintering adults and eggs.
2. Beneficial insects such as ladybugs and lacewings are important natural predators of this pest. For best results, release when pest levels are low to moderate.
3. If populations are high, use the least toxic and short-lived natural pesticide to establish control, then release predatory insects to maintain control.
4. Diatomaceous earth does not contain toxic poisons and acts quickly upon contact. Sprinkle vegetable crops lightly and evenly wherever adults are present.
5. Safer® insecticidal soap works quickly for severe infestations. A natural pesticide with a short duration of action, it works by damaging the outer layer of soft-bodied insect pests, causing dehydration and death within a few hours. If insects are present, apply 2.5 oz/gallon of water, repeat every 7-10 days as needed.
6. Surround WP (kaolin clay) forms a protective barrier film that acts as a broad spectrum plant protectant to prevent damage from insect pests.
7. BotaniGard ES is a highly effective biological insecticide containing Boveria Bassiana, an entomopathogenic fungus that affects a long list of crop pests, even resistant strains! Weekly applications can prevent insect population explosions and provide protection equal to or better than conventional chemical pesticides.
8. 70% neem oil is approved for organic use and can be sprayed on vegetables, fruit trees and flowers to kill eggs, larvae and adult insects. Mix 1 oz/gallon of water and spray all leaf surfaces (including the undersides of the leaves) until they are completely wet.
9. If pest levels become unbearable, treat areas every 5 to 7 days with an insecticide approved for organic use. Effective control requires thorough coverage of both the top and bottom of infested leaves.

Tip: Don't over fertilize - sucking insects such as plants with high nitrogen levels and soft new growth.