Grape Leafroll Virus & Pierce’s Disease
Vector Suppression have become
Important Components of Vineyard IPM
Dan Horton, UGA, Entomology, Athens, GA
Grape Leafroll Virus (GLRV) is the most a recent
insect-vectored disease to threaten to
vineyard health in the SE,
however GLRV is not an endemic disease, that is
virus-infected wild grapes are not common
and the most competent mealybug vector,
vine mealybug is not yet present
Monitor for Mealybugs Under Bark in Dormant Season
Incorporate examination of vines for mealybugs and/or
honeydew into your routine vineyard management
practice
If mealybugs are found/suspected take samples and get
them to your County Agent
Treat with either foliar applications or soil-applied
neonicotinoids: Venom/Scorpion, Clutch, imidacloprid, …
Applaud
Movento
chlorpyrifos, diazinon best with dormant oils
Grape Leafroll Virus work to avoid inadvertently introducing the
virus, virus-indexed vines may be of help
Recognize that PD/leaf-hopper suppression programs will tend
to increase the abundance of previously uncommon, then
insignificant, phloem-feeding pests such as mealybugs and
soft scales
Mealybugs & soft scale will overwinter in vineyards, implement
delayed dormant/bud swell horticultural oil programs to
suppress MBs, soft scale, armored scale and mites, adding
chlorpyrifos is good
As-needed new shoot treatments:
Applaud, Venom, Assail, imidacloprid, Movento …
• Pseudococcus (P. longispinus, P.
viburni or P. maritimus) would most
likely be North GA’s key Leaf roll Virus
Vectors (Greg Hodges, UFL, DPI)
Longtailed Mealybug
Pseudococcus longispinus
Grape Mealybug
Pseudococcus maritimus
Vine Mealybug ***
Pseudococcus ficus
Obscure Mealybug
Pseudococcus obscurus
Genus
species
Validation Source
Antonina
graminis
HendriKo1999
Antonina
pretiosa
HendriKo1999
Antoninoides
nortoni
HendriKo1999
Crisicoccus
taxodii
Koszta1996
Dysmicoccus
boninsis
Ferris1950b, BenDov1994
Dysmicoccus
milleri
Koszta1996
Dysmicoccus
morrisoni
MillerMc1973, BenDov1994
Dysmicoccus
obesus
ThompsCo1990, BenDov1994
Ferrisia
gilli
GullanDoSt2003
Oracella
acuta
Koszta1996, ClarkeNeDe1992
Paradoxococcus
mcdanieli
Koszta1996
Planococcus
ficus
EzzatMc1956
Pseudantonina
giganticoxa
HendriKo1999
Genus
species
Validation Source
Pseudococcus
bryberia
GimpelMi1996
Pseudococcus
comstocki
McKenz1967, BenDov1994
Pseudococcus
maritimus
GimpelMi1996
Pseudococcus
sorghiellus
McKenz1967, BenDov1994, GimpelMi1996
Pseudococcus
spanocera
GimpelMi1996
Pseudococcus
viburni
GimpelMi1996
Rhizoecus
floridanus
Hamble1973, BenDov1994, Koszta1996
Rhizoecus
spinipes
Hamble1976, BenDov1994
Stemmatomerinx
adenticulata
HowellMi1976, BenDov1994
Stemmatomerinx
aristida
HowellMi1976, BenDov1994
Stemmatomerinx
beshearae
HowellMi1976, BenDov1994
Trionymus
caricis
MillerMc1973, BenDov1994
LH Suppression has Slowed the Spread of PD in CA
Vector Suppression is More Complicated in the Verdant,
but Droughty Southeast
Soil-Applied Neonicotinoids: imidacloprid (Admire,
Alias, other generics) or Venom/Scorpion can either
languish if too dry or suffer reduced residual if too wet,
wait until as late in the initial
growth flush
as rain patterns suggest
Suggest LH Trapping as the Triggered for Foliar
Applications, they are responsive, targeted and they
complement neonicotinoids
Foliar Treatments Should Alternate Applications of
Pierces Disease and Leafhoppers are Endemic & Present
on both Wild & Cultivated Grapes Across the Southeast
P
Pierce’s Disease Management should be an on-going effort
to minimize leafhopper abundance to slow PD infection
Leaf hopper abundance in N GA is typically low
during the Spring vegetative growth flush,
insecticidal suppression of leafhoppers should
target the on-set of GWSS in vineyard,
a foliar pyrethroids/Imidan program is suggested
Neonicotinoids & Pyrethroids are Resistance-Prone &
Inclined to Increase the Risk of Mites;
Nicotinoids, Pyrethroids & Organophosphates (OP) are
Injurious to Pollinators;
A Balanced Program is More Likely to Suppress LH &
MB Vectors while Avoiding or Delaying Insecticide
Resistance
Spotted Wing Drosophila (SWD) was problematic in
VA wine grapes in 2012, while grapes are not felt to
be a prime host, SWD can successfully attack sound
fruit, hence it should be regarded as a threat
Spotted Wing Drosophila (SWD) Trapping should be
a standard operating procedure, augmented by
frequent fruit examination. SWD should be easily
controlled, but if it attacks N GA vineyards it will
require an aggressive, scheduled insecticide program.
Japanese Beetles are Significant
Foliage Pests, and Modestly
Important, Occasional Fruit Pests of
Muscadine Grapes
Japanese beetle populations get out of hand quickly,
especially as soaking, drought-breaking rains prompt
heavy, synchronous adult emergence
Defoliation from Japanese beetle is more serious as
grapes reach veraison, berry ripening, greater than
10% defoliation is probably injurious, but the key to
managing Japanese beetles is to act before they
become truly numerous
Japanese Beetle Insecticide Options in Muscadine
acetamiprid (N) Assail 12-h/7-d
++++
cyfluthrin (P) Baythroid, Tombstone 12-h/3-d
++++
bifenthrin (P) Fanfare, Tundra 12-h/30-d
++++
carbaryl (C) 12-h/7-d
++++
diazinon (OP) 24-h/28-d
+++
dinotefuran (N) Venom 12-h/24-h*
++++
fenpropathrin (P) Danitol 24-h/21-d
++++
imidacloprid (N) Merit, Provado 12-h/DOH
++++
malathion (OP) 12-h/3-d12-h/3-d
+++
methomyl (C) 7-d/1 to 14-d
+++
phosmet (OP) Imidan 14-d/ 7 to 14-d
++++