Grape vine Injurious Insects

A Lecture To ToT trainees ( FFS)

By Mr. Allah Dad Khan

Provincial Coordinator IPM KPK

MINFAL Pakistan

Grape Plume Moth, Geina persicelidactylus (Fitch) (Lepidoptera: Pterophoridae)

• The grape plume moth overwinters in the pupal stage. Adult moths emerge during the spring and lay eggs on grapevines. Hatched larvae feed on the upper grape leaf surfaces. Typically, a grape plume moth larva folds and webs the edges of a terminal leaf together and feeds within the fold. The larva is yellow with white hairs and about 5/8 inch long when fully grown. The adult moth is light brown with whitish markings and is 1/2 inch long. There is one generation each year.

Grape Sawfly, Erythraspdes vitis (Harris) (Hymenoptera: Tenthredinidae)

• The grape sawfly is a small, black, wasp-like insect that lays its eggs on the undersides of terminal grape leaves. The larvae that hatch from these eggs feed in a characteristic side-by-side manner at the edge of the leaf. Only the heaviest leaf veins are not eaten. When the larvae are fully grown, they drop to the ground, form cocoons and pupate. Two generations may occur in a single season.

• Damage caused by the grape sawfly rarely achieves economic proportions.

Eight-spotted Forester, Alypia octomaculata (Fab.) (Lepidoptera: Nocmidae)

Grapevine Epimenis, Psychomorpha epimenis (Dury) (Lepidoptera: Noctuidae)

• The larva of the grapevine epimenis is similar to that of the eight-spotted forester, and the two species are often confused in the field. The epimenis larva is bluish-white, and each segment of the body is marked by four transverse black stripes. There is a black-spotted red band on the eighth segment. The head, cervical and anal plates are red with black spots. The larva is about 3/4 inch long when fully grown.

• The adult of the grapevine epimenis is a velvety-black moth. Across the outer portion of each front wing there is an irregularly shaped white patch. On each hind wing there is a large, smooth-shaped orange-red or brownish-red patch. This" moth is about 7/8-1 inch in length.

• Grape Leaf Folder, Desmia funeralis (Hubner) (Lepidoptera: Pyralidae)• Damage caused by larvae of the grape leaf folder is usually minor in vineyards under a regular

spray program for other insect pests. The larva, a pale green caterpillar about 1 inch long when fully developed, either folds or rolls a leaf, ties the edges with silk and feeds on the upper surface, concealed within the fold. When leaves are rolled, the larva feeds within the free edge of the leaf. The result of such feeding is skeletonized leaves.

• This moth overwinters as a pupa. During early May, adult moths emerge from the pupae. An adult moth has dark brown wings with a spread of about 9/10 inch. The wings have a white border; each forewing has two nearly oval white spots. Each hindwing has one white spot, which may be divided in the female. The body is black and is crossed by two white bands in the female and one white band in the male.

Spotted Pelidnota, Pelidnota punctata (L.) (Coleoptera: Scarabaeidae)

• The adult spotted pelidnota is a reddish-brown beetle with three black spots on each wing cover, and one on each side of the prothorax is 3/4-1 inch long. The adult beetle feeds on grape leaves, skeletonizing them. Large-scale infestations do not occur on grapes.

• The larvae feed and live in decaying hardwood stumps, roots and logs, and do not harm grapes. The life cycle of this beetle requires two to three years to complete

Green Fruitworms (Lepidoptera: NoctUidae)

• The most common species of fruitworm known to feed on grape is the pyramidal fruitworm,Amphipyra pyramidoides (Guenee). Two other species,

• Lithophane antennata (Walker) and Orthosia hibisci (Guenee), also feed on grape foliage.• The pyramidal fruitworm overwinters in the egg stage. Near the end of April, larvae emerge from these

eggs and proceed to feed on the new grape foliage. By mid- to late June, the larvae are fully developed. They either crawl or drop to the soil surface and manufacture a cocoon of silk and debris. During the first part of July, adult moths emerge; these moths do not lay eggs until about the end of September. Eggs are placed individually or in small masses on old canes.

• The larva of the pyramidal fruitworm is green with a yellow line along each side of the body. It is 1/2 inch long when fully developed.

Grape Leaf Miner, Antispila viticordifoliella Clemens (Lepidoptera: Heliozelidae)

• The larva of the grape leaf miner is a small caterpillar that feeds between the upper and lower leaf surfaces. When the larva is fully developed, it pupates within the area of the leaf where it has been feeding; this section eventually falls out, leaving a hole in the leaf.

• The grape leaf miner is not an economically important insect; however, small numbers usually occur in vineyards, particularly in abandoned and backyard plantings.

• Grape leaf damaged by larva of the grape leaf miner. The leaf miner larva feeds between the upper and lower leaf surfaces. The section of the leaf damaged in this manner eventually falls out.

Grape Tube Gallmaker, Cecidomyia viticola Osten -Sacken

• Several species of small flies, or midges, are known to cause galls on various parts of grapevines. The adult flies lay their eggs either on or in leaves, leaf petioles, tendrils or cluster stems. Fleshy or blister type galls, depending on the species of fly, are formed when the eggs are deposited inside the plant or when the larvae emerge from the eggs and begin to feed. When these larvae are fully grown, they leave the galls, fall to the soil and pupate. Some species may have more than one generation per year.

• The grape blister gall is caused by a midge, Cecidomyia sp. This gall may be pink or green and about 1/8 inch in diameter. It occurs on leaves, and a single leaf may contain several galls. The grape tomato gall is caused by several midges, the more common one probably being Lasioptera vitis Osten-Sacken. The tomato gall is a green or red leaf or tendril gall, 1/4-3/4 inch in diameter. The midge Cecidomyia viticola Osten-Sacken is responsible for the formation of the grape tube gall, a conical red or green leaf gall 1/4 inch long.

• These gall-forming flies do not often inflict economic injury on grapevines. Removing the galls from the vines mayor may not be of some benefit in reducing the numbers of flies present in a vineyard. Such an action should be taken before small holes are seen in the galls as this indicates that the larvae have already emerged.

Grapevine Aphid, Aphis illinoisensis Shimer (Homoptera: Aphididae)

• The grapevine aphid is rarely a serious pest of cultivated grapes. The aphids pass the winter in the egg stage on viburnum. Hatching begins in early spring. Initially, wingless generations are produced, after which winged individuals make their appearance and fly to vineyards. Colonies of the aphid develop on the young shoots and leaves. The aphids are dark brown and the adult females are about 1/10 inch long. In the fall, winged aphids again develop; they return to viburnum and give rise to the egglaying females.

• There are numerous natural enemies of the grapevine aphid, including ladybird beetles, lacewings, syrphid fly larvae and parasitic wasps, which usually exert some degree of control on the aphids. This insect normally does not pose a serious threat to grapevines.

GrapeBranch and Twig Borer

• DAMAGE• Both adults and larvae injure grapevines.

Larvae bore into wood at dead or dying parts of vines, often in old pruning scars. Adults burrow into fruiting canes at the base of the bud or shoot, or they burrow into the crotch formed by the shoot and spur. Feeding is often deep enough to completely conceal the adult in the hole. Feeding at the base of shoots on spurs will cause shoots to wilt (flagging) and fall. This pest is most serious in cane-pruned vineyards where feeding on canes can cause them to break when shoots reach a length of 10 to 12 inches, if a strong wind occurs. Shoot wilting can also be caused by Botrytis.

• Scientific name:Melalgus (=Polycaon) confertus

GrapeCutworms

• DAMAGE• Feeding on grapevines occurs from bud

swell to when shoots are several inches long. Injured budsmay fail to develop. Grapevines can compensate for early-season damage to buds or shoots to some extent by the growth of secondary buds. The fruitfulness of secondary buds, however, varies according to variety, and some varieties such as Thompson Seedless and Chardonnay have unfruitful or significantly less fruitful secondary buds respectively. In these varieties, destruction of primary buds can be expected to reduce the number of clusters in proportion to the number of buds destroyed.

• Scientific names: Variegated cutworm: Peridroma sauciaSpotted cutworm: Xestia (Amathes) c-nigrum Brassy cutworm: Orthodes rufula and other species

GrapeDrosophila Flies

• DAMAGE• D. melanogaster and D.

simulans are a problem of damaged or cracked fruit. Eggs are laid in damaged or exposed fleshy tissue and larvae feed on the berries. The primary damage by this pest, however, is the sour rot organisms that it vectors from bunch to bunch in the vineyard.

• Scientific names: Drosophila melanogaster, D. simulans, and other species

GrapeGrape Leaffolder

DAMAGE

• Grape leaffolder can reduce leaf surface by constructing leaf rolls and by leaf feeding. Twenty percent leaf reduction can be tolerated 1 month after fruit set in the San Joaquin Valley. Even moreleaf damage can be tolerated later. However, third-generation damage can be severe enough to cause complete defoliation, which leads to sunburned berries, soft fruit, and direct berry feeding by leaffolder larvae.

• Scientific name: Desmia funeralis

GrapeLeafhoppers

DAMAGE

• Nymphs and adults of all three species remove the contents of leaf cells, leaving behind empty cells that appear as pale yellow spots or stippling. If populations are high, the entire leaf may be pale yellow or white. Loss of leaf efficiency and leaf dropcan occur when leafhopper densities are extremely high. This can result in fruit sunburn and may delay fruit ripening, especially in young vines. If there is a significant reduction in the overall photosynthetic capacity of the vine, young or stressed vines may have less shoot growth the following season.

• Scientific names: Western grape leafhopper:Erythroneura elegantulaVariegated leafhopper: Erythroneura variabilis Virginia creeper leafhopper:Erythroneura ziczac

GrapeVine Mealybug

DAMAGE

• Damage by the vine mealybug is similar to that of other grape-infesting mealybugs in that it produces honeydew that drops onto the bunches and other vine parts and serves as a substrate for black sooty mold. If ants are not present, a vine with a large population of this pest can have so much honeydew that it resembles candle wax. Also, the mealybug itself will be found infesting bunches making them unfit for consumption. Like the grape, obscure, and longtailed mealybugs, vine mealybug can transmit grapevine leafroll-associated viruses.

• Scientific name:Planococcus ficus

Thrips• DAMAGE• Table grapes are susceptible to fruit damage caused by the western flower thrips.

They createhalo-spotting on the fruit when they oviposit in berries during bloom and up to fruit set or shortly thereafter. Both western flower thrips and grape thrips can scar berries with their feeding, which renders certain white varieties used for table grapes unmarketable. Thrips scarring is primarily a problem on Red Globe, Calmeria, Italia, and occasionally on Thompson Seedless. Fruit feeding discontinues in summer when both species feed onnew vegetative growth

Grape Flea Beetle

• Adults are dark metallic greenish-blue, jumping beetles about 1/5 inch long; larvae are brownish and marked with black spots; eggs are pale yellow, and fairly conspicuous on upper leaf surface or under loose cane bark.

• • Adults overwinter in protected areas around vineyards,

and start feeding on interior of primary buds and opening grape leaves in early spring. Damaged buds will not develop into primary canes which can reduce yields. Once the buds are 1/2 inch long, only slight injury is caused. The females lay eggs under loose cane bark on vines, or occasionally on leaf upper surfaces, or on buds. The light yellow fairly conspicuous eggs hatch in a few days. The larvae feed on leaves for 3 to 4 weeks, then drop to the ground where they pupate in the soil, and emerge as adults in 1 to 2 weeks later. New adults feed for the remainder of the summer and go into hibernation in fall. There is only 1 generation per year.

Adults are dark metallic greenish-blue, jumping beetles about 1/5 inch long; larvae are brownish and marked with black spots; eggs are pale yellow, and fairly conspicuous on upper leaf surface or under loose cane bark. 

Adults overwinter in protected areas around vineyards, and start feeding on interior of primary buds and opening grape leaves in early spring. Damaged buds will not develop into primary canes which can reduce yields. Once the buds are 1/2 inch long, only slight injury is caused. The females lay eggs under loose cane bark on vines, or

occasionally on leaf upper surfaces, or on buds. The light yellow fairly conspicuous eggs hatch in a few days. The larvae feed on leaves for 3 to 4 weeks, then drop to the ground where they pupate in the soil, and emerge as adults in 1 to 2 weeks later. New adults feed for the remainder of the summer and go into hibernation in fall. There is only 1 generation per year.