White Grubs and Other Bad
Blueberry Bugs
Dr. Sridhar Polavarapu
Blueberry and Cranberry Research and
Extension Center
Rutgers University
Chatsworth, NJ 08019
In This Presentation ….
• Seasonal lifehistory and management of
above ground pests
• Pests feeding on roots
Seasonal Lifehistory and
Management of Major Pests
• Pests that occur during the dormant
stage
• Pre-bloom leaf and flower feeders
• Bloom-time insect pests
• Post-bloom pests on foliage and fruit
Pests During Dormant Stage
• Putnam scale is the main
concern
• Problem in under-pruned
fields
• Superior oil (70-second
type) @ 3 gal/ac
• Lime sulfur @ 5 gal/ac
• Apply on warm days (>50
F) before flower buds
begin to open
Pre-bloom Leaf and Flower-Feeders
• Cranberry weevil,
leafrollers, and
spanworms are the
major pests
• ET of one larvae per
100 clusters for
caterpillars
• For CW, treat if >5
weevils per bush or
20% injured flower
clusters
Bloom-time Insect Pests
• Gypsymoth larvae,
leafrollers, and aphids
are the main concern
• Bts and Confirm 2F
are the insecticide
options
• Same threshold as
pre-bloom
• No aphid controls
during bloom
Post-bloom Pests on Foliage and Fruit
• Cranberry fruitworm,
plum curculio, blueberry
aphids, and blueberry
maggot are the major pests
• Leafminers, and leafrollers
are occassional problems
• Most insecticide
applications are made
during this phase
Post-bloom Pests on Foliage and Fruit
Cranberry fruitworm
• Single generation per
year
• Pheromone traps are
used for monitoring
• Single insecticide
application 5-7 days
after the peak
• Typical timing June 1-5
Effect of timing of Confirm 2F applications on
efficacy against Cranberry Fruitworm
20
Larvae per 100 Clusters
15
% Damaged Clusters
a
a
10
5
b
b
b
0
b
b
b
Confirm
6/1&6/8
a
b
b
Diazinon
6/1&6/8
Confirm
5/25&6/1
Confirm
6/1
Control
CFW 2000
Post-bloom Pests on Foliage and Fruit
Blueberry aphids
• A complex of several species
• Vectors of blueberry scorch
and other viruses
•Species identified in NJ blueberries
• Illinoia azaleae
• Ericaphis spp.
• Macrosiphum euphorbiae, M. rosae
• Aphis spiraecola, A. gossypii
• Myzus persicae
Post-bloom Pests on Foliage and Fruit
Constraints in Managing Blueberry Aphids
Natural enemies
• Low tolerance because of vector status
• Use of broadspectrum insecticides
leading to natural enemy destruction
• Poor coverage
Evaluation of Imidacloprid Applied as
Soil Drench Against Blueberry Aphids
• Imidacloprid treatments at 0.25
and 0.5 lb A.I./acre were
evaluated as soil drench
• Four replications, 3 bushes per
replication
• Insecticide was applied in 1000
mL per bush on June 7
• Aphids were sampled on June 14
and 21
Evaluation of imidacloprid applied
as soil drench
80
60
a
a
a
a
% IT
a
a
a
b
40
b
20
a
300
Pre-spray 6/7
1st Post-spray 6/14
2nd Post-spray 6/21
Total Aphids
ab
200
a
a
a
a
100
b
b
b
0
Control
Imidacloprid
0.25 lb.ai/ac
Imidacloprid
0.5 lb.ai/ac
Evaluation of Foliar Applications
• Imidacloprid, Thiamethoxam, and
Thiacloprid were evaluated
• Four replications, four bushes per
replication in a single row
• R&D sprayer, 30 gal/acre, Conejet
4VS hollowcone nozzle
• Insecticides were applied twice on
June 6 and 13 and aphids sampled on
June 6, 12, and 21
Evaluation of foliar application of insecticides
a
80
% IT
a
60
a
a
a
b
40
a
bc
b
c
bc
c
20
300
a
Total Aphids
a
bc
a
b
b
100
Control
Calypso
480 SC 1.5
fl.oz/ac
c
Pre-Spray , 6/6
Post-Spray, 6/12
Post-Spray, 6/21
abc
200
a
c
ab
c
bc
bc
Calypso
480 SC 3.0
fl.oz/ac
c c
c c
Provado
1.6 F 3.0
fl.oz/ac
Actara 25
WDG
85.2g/ac
Post-bloom Pests on Foliage and Fruit
Blueberry maggot
Overwinters in the pupal stage
Adults emerge beginning June 10
Females need 10 days to become
reproductively mature
Calendar sprays begin 10 days after
adult emergence
Blueberry Maggot Management
• Quarantine pest
• Wide-window of emergence and
oviposition
• Presence of wild and voluntary sources of
infestation
• Research focus on monitoring and timing
of insecticide applications
Blueberry Maggot Export Regulations
• CFIA promulgated new regulations in
1999
• To qualify for export, grower must
participate in a BM Certification Program
• Growers are required to follow either a
calendar-based or IPM-based approach
for BM management
• Major constraint in IPM adoption
Blueberry Maggot Population Monitoring
Yellow boards
- hue
- reflectance
Spheres
- shape
- intensity
contrast with
background
Pherocon AM trap
Currently recommended
for monitoring
Red Sphere
Green Sphere
Insecticide-treated Spheres for
Blueberry Maggot Control
•
•
•
•
•
•
Ammonium acetate/carbonate
Color
Shape
Fruit volatiles
Sugar
Proteins
Root-feeding Pests - Oriental Beetle
White Grub Rastral Patterns
May-June Beetle
Oriental Beetle
Asiatic Garden
Beetle
Evaluation of Imidacloprid and Insecticidal
Nematodes Against Oriental Beetle
Treatment
Appl. Date Rate/acre Grubs/plant
Admire 2F
11 June
2 pints
2.1 C
Admire 2F
8 July
2 pints
2.1 C
Admire 2F
14 August
2 pints
3.8 C
Cruiser
8 July
2.0 bill
15.8 A
Cruiser
14 August
2.0 bill
9.1 B
Untreated
9.6 B
Imidacloprid for Scarab Grub Management
•Applied as a 40cm-wide band on
each side of the bush
•Works best against 1st instar
larvae
•Apply in early June to mid-July
•Irrigate before and after
application
•Apply in the evening hours
•Current blueberry registration
allows only a maximum of 0.3 lb
AI/acre/year for grub control
•The other 0.2 lb AI/acre/year is
used for foliar control of aphids
Greenhouse Evaluation of Insecticidal Nematodes
and Chloronicotinyls - 2001
12
# of Grubs
8
4
0
Treatment
Root-feeding Insects
Blueberry Mealybug
•Ant-mealybug relationship
•Disrupt this relationship
for control
Any Questions ?