White apple leafhopper

Adults begin appearing in early June. They are a pale yellowish-white color and measure about 3 mm long. Under close observation, particularly on the males, a slight orange tinge may be seen on the head and thorax.
Female WALH have about a 10-day preoviposition period and then produce eggs for about 3 weeks. They may live about a week after oviposition ceases.
Second brood WALH adults begin emerging about mid August and by early September most have emerged. They normally remain active until killed by the first good frost in the fall. When present in large numbers at harvest, second brood WALH adults can be a nuisance problem to pickers.
Eggs are deposited by the second brood females just beneath the bark surface on 1- to 5- year old wood. These egg laying sites appear as elongate, oval, blister-like swellings, measuring about 1.5 mm long, and characteristically run perpendicular to the terminal growth. Overwintered eggs begin hatching about late pink and hatch is completed by petal fall.
The second brood eggs are laid in the petiole, mid-vein and large veins of leaves from late June through mid July. These eggs begin hatching in late July and in some years emergence may continue into September.
Nymphs are about 1 mm long, pale white and wingless. The eyes of newly hatched nymphs are red and change to a pale white color with the first molt. They migrate to the undersurface of older leaves where they begin feeding. WALH nymphs pass through 5 instars and will characteristically complete their development on a single leaf or cluster of leaves. Their white cast skins frequently remain hanging from the leaf undersurface. As the nymphs reach the third instar the wing pads become noticeable. Fifth instra nymphs measure about 2.8 mm long.
Injury. WALH nymphs and adults are mesophyl feeders. Feeding injury causes a white mottling of the leaves and with heavy infestations the leaves can become nearly completely white.
Feeding WALH also excrete a honeydew which may drop onto lower leaves and fruit. Once dried on the fruit the honeydew appears as "tobacco juice" colored spots orstreaks that are difficult to remove. Under humid conditions, the honeydew remains moist and is an excellent media for sooty molds.