Plum and prune-Leafhopper

Includes

Rose leafhopper (Edwardsiana rosae)
White apple leafhopper (Typhlocyba pomaria)

Pest description and crop damage The common leafhopper pest in the PNW is the white apple leafhopper, although a very similar-appearing insect, the rose leafhopper, is also present. Other species are found throughout the Pacific Northwest. Adults are about 0.2 inch long, white to yellow in color, with wings held tent-like over the body. Nymphs are light green and may move rapidly if disturbed. Adults and nymphs suck juices from leaves, causing stippling and mottling on leaves. Damage usually is most noticeable on poorly cared-for trees. In general, this pest is a minor problem, and even high populations rarely cause yield loss. May become a nuisance pest during fruit harvest.

Biology and life history The insect overwinters as eggs just beneath the bark on 1 to 5 year-old twigs in the trees. Presence of the eggs is indicated by characteristic crescent-shape swellings in the bark. Eggs hatch at about the tight cluster stage (late March to mid-April), and nymphs feed for several weeks. Adults are flying by late May and can be observed from then until frost, when they are killed. Overwintering eggs are laid in September. There are two generations per year.

Pest monitoring As a minor pest, monitoring is not necessary, although presence of the adults can be confirmed by early morning limb taps.

Management-biological control

Parasitic wasps exert some control over leafhopper populations.

Management-chemical control: HOME USE

  • acetamiprid--Toxic to bees.
  • azadirachtin (neem extract)-Some formulations are OMRI-listed for organic use.
  • Beauveria bassiana-Some formulations are OMRI-listed for organic use.
  • carbaryl-Highly toxic to bees.
  • esfenvalerate-Highly toxic to bees.
  • gamma-cyhalothrin-Highly toxic to bees.
  • imidacloprid-Highly toxic to bees. Soil drenches may have residual activity in woody plants lasting for 12 or more months. If short-term management is the goal, consider other approaches.
  • insecticidal soap-May require several applications. Some formulations are OMRI-listed for organic use.
  • kaolin-Applied as a spray to leaves, stems, and fruit, it acts as a repellant to some insect pests. Some formulations are OMRI-listed for organic use.
  • lambda-cyhalothrin-Highly toxic to bees.
  • plant-derived essential oils-Some have shown efficacy against leafhoppers. Some formulations are OMRI-listed for organic use.
  • pyrethrins (often as a mix with other ingredients)-Some formulations are OMRI-listed for organic use.
  • spinosad- Toxic to bees. Plum only. Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin-Highly toxic to bees.

Management-chemical control: COMMERCIAL USE

Spring and summer spray

  • carbaryl (Sevin 4F) at 2 to 3 quarts/a. REI 12 hr. PHI 3 days. Extremely toxic to aquatic invertebrates; avoid spray drift and runoff to surface waters.
  • esfenvalerate (Asana XL) at 5 to 12 fl oz/a. REI 12 hr. PHI 14 days. Extremely toxic to fish and aquatic invertebrates; avoid spray drift and runoff to surface waters.
  • thiamethoxam (Actara) at 2.0 to 2.75 oz /a. REI 12 hr. PHI 14 days. Minimum interval between treatments 7 days. Actara is extremely toxic to bees exposed to direct treatment or residues. Do not apply Actara between the pre-bloom (swollen bud) and post-bloom (petal fall) growth stages.
  • thiamethoxam/chlorantraniliprole (Voliam Flexi) at 4 to 7 oz/a. Do not apply exceed 14 oz/a of Voliam Flexi per season. REI 12 hr. PHI 14 days.