Grape Leafhopper (Erythroneura spp.)

Fact Sheet 5.559 Insect Series | Crops

By Miranda Ulmer* Quick Facts Description Leafhoppers overwinter in plant Grape leafhoppers are pests of debris and leaf litter; grapes in Colorado. Both they emerge in the Erythroneura ziczac and spring and can be Erasmoneura vulnerata have been found on young grape identified in this region. Adult tissue. leafhoppers are approximately 0.12 inches (3 mm) long and are pale "Hopper burn" is yellow with reddish and brown result of nymphs and markings (Figure 1). Grape adults feeding on the leafhoppers have 1 to 4 generations contents of leaf cells per year. They overwinter as adults, Figure 1. Grape Leafhopper Photo by Bob and can result in fruit Hammon, CSUE retired Entomologist sunburn, delayed fruit usually in plant debris and leaf litter ripening and reduced in or around vineyards and shoot growth the surrounding residences. As Damage following season. temperatures increase in the spring, Nymphs and adults feed on the adults emerge from overwintering contents of leaf cells, leaving behind Significant leafhopper sites. Adults can be found on grape empty cells that appear as pale- populations (<15-20) foliage after budburst as new yellow spots or stippling. “Hopper can be tolerated by growth develops in the vineyard. burn” is the browning, yellowing, the grapevine without Leafhoppers can be found in the stunting and curling caused by economic loss. vineyard until movement to severe feeding of leafhoppers and is overwintering sites takes place in very characteristic of this pest Parasitic wasps of the the fall. (Figure 2). The first generation of genus Anagrus can cause up to 100% nymphs feed primarily on basal mortality of Eggs are 0.03 inches (0.8 mm) long, leaves whereas the second leafhopper eggs. bean-shaped, and commonly laid generation can be found closer to just beneath the epidermis on the the shoot tip feeding on younger underside of leaves, producing a leaves. amage is first found along slight protuberance. The eggs are the veins, but the whole leaf can be colorless and laid singly. The affected. Leafhoppers in high nymphs are semi-transparent/white densities can turn the entire leaf *Miranda Ulmer, Colorado State University Extension State Specialist - and pass through five nymphal yellow or white resulting in a decline Viticulture. (12/19) instars. in photosynthetic activity and the potential for leaf drop.

extension.colostate.edu 1 © Colorado State University Extension. 12/19. This may result in fruit sunburn and Cultural control - It is important to eliminate favorable delayed fruit ripening during the leafhopper overwintering sites by removing vineyard debris. current season and a potential Also, mowing of cover crops early in the season can reduce reduction in shoot growth the adult populations. In addition, removal of basal leaves following season. Additionally, small improves spray efficiency by allowing for better spray drops of excrement can be found on penetration. berries and foliage, which is commonly associated with the Mechanical control - Sticky traps can trap adult leafhoppers. development of sooty molds which Products like Tanglefoot or Vaseline can be used to trap the can decrease fruit quality. pest.

Chemical control - Good coverage of all leaf surfaces, including the underside of the leaf, is crucial for chemical control.

(REI: Re-Entry Interval, PHI: Preharvest Interval).

Imidacloprid (Wrangler): Apply 1.2-1.6 fl oz/acre (foliar) REI: 12 hours PHI: 0 days Comments: Toxic to bees, fish and wildlife. Apply when bees are not present. (Imidacloprid Figure 2. Western grape leafhopper by Photo by applied to foliage when plants are not flowering has no impact Eugene E. Nelson, Bugwood.org on bees. B ees will not be present in vineyards once flowers Management have gone). Significant populations of leafhoppers can be tolerated by the grapevine Acetamiprid (Assail 70WP): 1.1 – 2.3 oz/acre. REI: 12 hours without economic loss. However, PHI: 3 days. Comments: Apply when bees are not present. more than 15-20 leafhoppers per leaf may be detrimental and at this Kaolin clay (Surround WP): Apply 20-25 lb product/acre threshold treatment is recommended. REI: 4 hours PHI: 0 days Comments: Some formulations are OMRI-listed for organic use. Biological control - Natural enemies of leafhoppers include lacewings, Horticultural/mineral oil: Control of Nymph stage. Consult label predatory beetles, spiders and for rates Comments: Some formulations are OMRI-listed for parasitic wasps. Parasitic wasps of the organic use. genus Anagrus are tiny and cause eggs to turn red prior to the Insecticidal soap: Control of Nymph stage. Consult label for emergence of the adult wasp. High rates Comments: Some formulations are OMRI-listed for densities of this parasitic wasp can organic use. cause up to 100% mortality of leafhopper eggs. Many other insect Note: Virginia creeper can be used as a trap crop as the predators like spiders, minute pirate insects are more attracted to it over grapes. Chemical controls bugs and lady beetles will eat of the insect on Virginia creeper can reduce pest pressure on leafhoppers. grapes but monitoring should occur.

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References 1. Grape-Leafhopper. 2019. Pacific Northwest Pest Management Handbooks. 2. Grape Leafhoppers. 2019. UC Pest Management Guidelines http://ipm.ucanr.edu/PMG/r302300111.html. 3. Grape Leafhopper. 1984. Cornell University Extension Grape Insect IPM. 4. Zimmerman et al. 1996. The Life History of Two Species of Grape Leafhoppers on Wine Grapes in Western Colorado. Journal of the Kansas Entomological Society 69(4) 337-345.

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