Upload
nigel-richardson
View
214
Download
0
Embed Size (px)
DESCRIPTION
1st generation larva moves for a few hours then slips between 2 or 3 flower buds where it perforates the flower envelopes and penetrates the bud Larvae of later generations move briefly before attacking the fruits; they web several fruits together then feed on them Feeding opens up fruit to fungal infection Damage Grape Damage Grape Berry Moth Mark - for grape berry moth cite:
Citation preview
Grape Insects
Frank G. Zalom, Department of Entomology, UC Davis
• 2 to 4 generations a year
• Larva yellowish-green to greyish- green, brownish-yellow head
• When larva is disturbed, it drops to the ground, suspended by a silk thread
About Grape About Grape Berry Moth, Lobesia
•1st generation larva moves for a few hours then slips between 2 or 3 flower buds where it perforates the flower envelopes and penetrates the bud
•Larvae of later generations move briefly before attacking the fruits; they web several fruits together then feed on them
• Feeding opens up fruit to fungal infection
Damage Grape Damage Grape Berry Moth
Mark - for grape berry moth cite:http://www.inra.fr/hyppz/RAVAGEUR/6lobbot.htm
• Treat with IGRs and foliar-applied neonictotinoids
• Pheromone mating disruption possible
• Monitoring with pheromone traps
Solutions Grape Solutions Grape Berry Moth
Mark - for grape berry moth cite:http://www.inra.fr/hyppz/RAVAGEUR/6lobbot.htm
•Adults are ~3 mm long, often with distinct markings
•Eggs are laid in the underside of the leaves in spring, and appear as a bean-shaped, blisterlike raised area slightly less than 1 mm long
•Nymphs are similar to adults, but are smaller and wingless
About Grape LeafhoppersAbout Grape Leafhoppers
Damage
•Nymphs and adults remove the contents of leaf cells, causing stippling on leaves
•Leaf burn and drop can occur at high densities
•Honeydew and excrement on berries and growth of sooty mold results in berry spotting
•Vines can tolerate fairly high populations without harm
Grape LeafhoppersGrape Leafhoppers
•Parasitized leafhopper eggs become visibly red•General predators include spiders, lacewings, minute pirate
bugs, lady beetles, and predaceous mites•Wait until the second generation before treating with more
disruptive insecticides•Systemic neonicotinoid insecticides can be applied
preventatively
Solutions
Parasitized egg
•Egg parasites, Anagrus spp., are more abundant in vineyards adjacent to fruit trees, vines, and riparian areas
Grape LeafhoppersGrape Leafhoppers
About MealybugsAbout Mealybugs•Adults- ~5 mm long, flat, oval
shaped, and have a white waxy covering
•2 - 3 generations per year •Larvae overwinter on the vines,
under loose bark• In spring, most mealybugs
move to the base of spurs and then onto expanding green shoots and clusters
•Crawlers (1st instars) are yellow to orange-brown in color
Crawlers
MealybugsMealybugs
•Results when clusters are contaminated with egg sacs, mealybugs and honeydew; often the honeydew is covered with black sooty mold
•Can transmit certain grape viruses
Damage
MealybugsMealybugs
•Infestation may slowly spread unless controlled with an insecticide
•Monitor parasitism by collecting mealybugs and holding them in gelatin capsules to detect parasite emergence; if parasitism is found, leave untreated areas of the vineyard to provide refuges for parasites
•Train vines so that clusters hang freely and do not touch the wood
•Control ants which deter parasitoids
Solutions