Insect Management Guide


Fact Sheet No. 209, UMaine Extension No. 2001


 

NOTICE: It is unlawful to use any pesticide for other than the registered use. Read and follow the label on the product container. The user assumes all responsibility for a use inconsistent with the label. This fact sheet is to be used only during 2019. Use in subsequent years may lead to improper and illegal use of pesticides. When this guide is outdated, please request an updated version from your Extension office.

For toxicity ratings of wild blueberry insecticides, refer to the 2020 Maine Wild Blueberry Pesticide Chart, Insecticides (PDF).

WARNING! Pesticides are potentially hazardous. Handle carefully! Read and follow all directions and precautions on labels. Store in original labeled containers out of reach of children, pets, and livestock. Dispose of empty containers at once, in a safe manner and place. Do not contaminate forage, streams, ponds or groundwater recharge areas.

Groundwater is a major natural resource. Pesticides have been detected in the groundwater of all states. A sound application program including site-specific selection, adherence to label directions, sprayer calibration mixing accuracy, spill and back-siphon prevention, proper waste disposal, integrated pest management, and judicious pesticide use can prevent groundwater contamination.

Trade names are used for identification. No product endorsement is implied, nor is discrimination intended against similar materials. Cooperative Extension makes no warranty or guarantee of any kind concerning the use of these products.

Blueberry Spanworm

Begin to monitor for spanworm larvae in early spring as the buds break and plants emerge by sweeping with a 12-inch diameter sweep net.  Spray with an insecticide or biocontrol when larval counts on fruit-bearing plants average over 10 per 10 sweeps.  The action threshold should be lowered to 3 or more larvae per 10 sweeps on vegetative year fields.  Repeat treatment, if necessary.  More information may be found in the Wild Blueberry Fact Sheet No. 197 (UMaine Extension No. 2371), Blueberry Spanworm. Burn or fire pruning will also reduce likelihood of damaging populations.

Blueberry Flea Beetle

An action threshold of 50 insects per 10 sweeps has been established for either larvae or adults. Examine fields in early spring for larvae and from mid-June to early July for foliar feeding by adults.  Spray with an insecticide or biocontrol as needed.  More information can be found in Wild Blueberry Fact Sheet No. 200 (UMaine Extension No. 2372), Blueberry Flea Beetle. Burn or fire pruning will also reduce likelihood of damaging populations.

Thrips

When leaf curling occurs in a fruit bearing year, stake out infested area. The following spring, apply insecticide to the staked area before curling reoccurs. Make first application when leaves are 1/4 inch to 1/2 inch long. Repeat when 1/2 inch to 1 inch. These timings are critical. Yellow sticky cards may be used to monitor for blueberry thrips for more efficient timing of applications. A delayed burn in the fruit-bearing year may also be considered; see the cultural techniques section.

Refer to Wild Blueberry Fact Sheet No. 204 (UMaine Extension No. 2275), Integrated Crop Management Field Scouting: Guide for Lowbush Blueberries and Wild Blueberry Fact Sheet No. 202 (UMaine Extension No. 2373), Blueberry Thrips.

Blueberry Maggot

Monitoring for the presence of the blueberry fruit fly will indicate necessity for control based on trap capture threshold and, if needed, to ensure proper timing of insecticide applications. Refer to the blueberry maggot fly factsheet (Cooperative Extension Fact Sheet No. 201 (UMaine Extension No. 5030), Monitoring for the Blueberry Maggot) to learn about field perimeter treatments, spot treatments, and maintaining isolated fields on one production cycle.

Never apply insecticides when less than three to five percent of berries have ripened and turned blue. This is usually early July in most regions of Maine. Repeat applications, if necessary, depending on trap capture results.

Spotted-Wing Drosophila

The Spotted-Wing Drosophila (SWD) is an invasive non-native small vinegar fly with the potential to cause considerable fruit loss of wild blueberries especially at the end of the harvest season.  It was first detected in Maine in 2011. Unlike most other vinegar flies that require damaged fruit to attack, SWD causes damage when the female flies cut a slit and lay eggs in healthy fruit. Monitoring for the presence of the SWD requires a different trap, placement and timing than our native blueberry maggot fly. See Extension Fact Sheet: Spotted-Wing Drosophila Traps at Extension Fact Sheet: Spotted-Wing Drosophila Traps.

Apply insecticides using action thresholds. A threshold of an average of 0.5 cumulative male fly / trap is a very conservative threshold where the following week the expected probability of fruit infestation is expected to be 0.5%. A threshold of an average of 3.5 cumulative male flies / trap is a moderate risk threshold where the following week the expected probability of fruit infestation is expected to be 10%. A Threshold of an average of 7 cumulative male flies / trap is a higher risk threshold where the following week the expected probability of fruit infestation is expected to be 25%. These thresholds are based upon the use of 3 SWD traps along a blueberry field edge baited with sugar syrup and yeast (see recommendation table for SWD monitoring and for insecticide class).

All publications may be found on the Fact Sheets page of the Cooperative Extension: Maine Wild Blueberries website. Or by request from Cooperative Extension by calling 1.800.897.0757 x 1.

Pest Management Charts (pdfs)

Are you sure you need to act?

It is critical that we make sure an insect pest is present in a field before taking a management action. Managing an insect is expensive in labor, equipment, and products so make sure you have a problem before taking action.

Scouting and adopting action thresholds to inform management decisions a key to reducing unnecessary or untimely applications of pesticides. Comprehensive guides and information on how to trap, scouting and recommended action thresholds for insect pest can be found on the here:

Trapping, Scouting & Threshold Guides

Cultural Insect Management in Wild Blueberry
Insects Method Comments
Blueberry Maggot Harvesting Harvesting techniques that reduce fruit loss can minimize the number of infected fruits left on the plants and on the ground.
Management Keep isolated fields in same cycle.
Winnower cleanup Compost, burn or dispose of winnower refuse.
Flea Beetle, Sawfly, Spanworm Fire pruning Blueberry litter must be ignited.
Thrips Fire pruning Burn curled stems as soon as extensive curling occurs in early spring, but not later than July 1 in a nonbearing crop or reduction in next year’s fruit buds will occur.
Spotted wing drosophila Early Harvest Monitor adult and larval populations; Refer to Cooperative Extension Bulletin No. 210, Spotted Wing Drosophila: Pest Biology and IPM Recommendations for Wild Blueberries for additional information

When Using Pesticides Follow ALL label directions.

  • Accurate identification of pests and monitoring to determine the best times to spray are critical for achieving effective, economical control.
  • Apply pesticides only when economic thresholds are exceeded, based on the monitoring.
  • Use caution while loading spraying equipment with pesticides. Follow all safety precautions.
  • Use common sense when applying pesticides. DO NOT contaminate nearby lands, buildings, water bodies, and roadsides. Keep domestic animals and children away from fields.
  • For detailed information on safe spray use, please refer to the Wild Blueberry Growers Guide.
  • Avoid aerial application of pesticides near buildings, public roads or water supplies or on windy days.
  • Reentry restrictions: never enter a sprayed area without protective clothing or until stated on the label.
  • Be sure your sprayer is well cleaned and does not have any fungicide residue when using Botanigard since fungicide will kill the living spores.

Protecting Honey Bees from Insecticides

  • Refer to Cooperative Extension Bulletin No. 2009, IPM Tactics to Reduce Pesticide Exposure to Honey and Native Bees for additional information.
  • All pesticides are not equally hazardous to bees. Select the one that is least hazardous. Commonly used insecticides are listed in the chart according to their relative hazards.
  • Do not apply insecticides near honey bee hives.
  • Treat plants ONLY before (check persistence for each insecticide, for instance, Phosmet is 7-10 day persistence) or after bloom, or when bees are not actively foraging in the crop (before or after bloom) and pruned fields.

INSECTICIDES

F1 Extremely toxic to fish B1 Extremely toxic to bees D1 Extremely toxic to birds P1 Extremely toxic to people
F2 Moderately toxic to fish B2 Moderately toxic to bees D2 Moderately toxic to birds P2 Moderately toxic to people

THIS CHART IS NOT A SUBSTITUTE FOR READING AND FOLLOWING THE LABEL. It is unlawful to use any pesticide for other than the registered use. Read and follow the label on the product container. The user assumes all responsibility for use inconsistent with the label. Trade names are used for identification.  No product endorsement is implied, nor is discrimination intended against similar materials. Cooperative Extension makes no warranty or guarantee of any kind concerning the use of these products. Check with your processor regarding PHI restrictions or MRL restrictions for export sales.

BMF = Blueberry Maggot, SL = Spanworm Larvae, FB = Flea Beetle, SRW = Strawberry Root Worm, SWD = Spotted Wing Drosophila

S = systemic, NS = not systemi

Spotted Wing Drosophila Control     0=Not Effective    1=Slightly Effective    2=Moderately Effective    3=Effective    4=Very Effective

Use & Toxicity

Insecticide

AI/Group & Signal

Rate:

Per/Acre & Max/Acre/yr

PHI

REI

Notes

BMF, Thrips P2
B1
D1
Admire Pro Systemic Protectant imidacloprid
Group 4A
Warning Foliar 2.1 to 2.8 oz
Max: Foliar: 5 app; 14 oz (0.5 lb ai) for all
Foliar 3 12 hrs Do not use prior to or during bloom. Highly toxic to bees if used as a foliar spray during bloom. Foliar: For sprout application during emergence of thrips and tip midge.  Apply at least 7 days apart.
Human & Environment: S, 7 day persistence
BMF, SL P2
B1
D1
Asana XL esfenvalerate
Group 3
Danger 4.8 to 9.6 oz
Max: 38.4 oz (0.2 lb ai)
14 12 hrs Do not apply within 7 days of pollination.
Human & Environment: NS, 7 day persistence
BMF, FB, SWD B2
SWD 2
Assail 30 SG  acetamiprid
Group 4A
Caution 4.5 to 5.3 oz
(SWD – 5.3 oz)
Max: 5 app;
26.7 oz (0.5 lb ai); 2 consecutive applications
1 12 hrs Do not apply more than once every 7 days. Add 1 lb/a sugar to spray tank to enhance performance for SWD ONLY. Toxic to bees exposed to direct treatment; do not apply while bees are actively visiting treatment area.
Human & Environment: S, 7 day persistence
Assail 70 WP 1.9-2.3 oz
Max: 11.4 oz (0.5 lb ai)
SWD SWD 1 AzaGuard, AzaSol
(Multiple products registered)
(AzaGuard OMRI expires 12/1/19)
neem, azadirachtin
Group unknown
Caution Foliar 10-16 oz (see notes for exceptions) + COC 1% v/v
(rates listed only for Azaguard)
Max: None; 22.5 oz AzaGuard per app (0.75 lb/20 g ai all azadirachtin per app)
4 hrs  Effective on SWD under low to moderate pressure; once SWD numbers build, switch to another product. When infestation is heavy or canopy dense, use up to 2x rate, not to exceed 22.5 oz/a/application. Use ½ rate when combining with other insecticides. Do not mix with highly alkaline products or exceed mix pH 7. Label recommends 2-3 applications at 7-10 day intervals.
Human & Environment: NS, 7 day persistence
SL   Bacillus thuringiensis, several formulations registered Bacillus thuringiensis
Group 11
  See label
Max: —-
check label 4 hrs May use when bees are present. Most effective on small early instar blueberry spanworm larvae. This bio-insecticide is NOT effective against winter moth larvae.  Do not apply within 300 ft of any threatened or endangered Lepidoptera.  Product(s) may be OMRI listed, e.g. Javelin WG.
Human & Environment: NS, 3 day persistence
FB P1 BotaniGard ES Beauveria bassiana
Group M
Caution ½ -1 qt
Max: none
0 4 hrs Apply at 5-10 day intervals in the evening as sunlight destroys spores. Clean all fungicide residues from tank as they will destroy the Beauvaria spores and inactivate the product.
Human & Environment: NS, 2 day persistence
BMF, FB, SRW, SWD F1
B1
SWD 4
Delegate WG spinetoram
Group 5
Caution 3 to 6 oz
(3-6 oz SWD)
Max: 6 app (3 for thrips); 19.5 oz (0.305 lb ai)
3 4 hrs Do not apply more than once every 6 days, and no more than two consecutive applications of any Group 5 insecticide. Highly toxic to bees if sprayed or come into contact with wet treated foliage. If foliage is dry, toxicity is very low to bees. Do not rotate with spinosad products.
Human & Environment: NS, 5 day persistence
Thrips P2
F1
B1
D1

Toxic to shrimp and crab
Diazinon
Several formulations registered
diazinon
Group 1B
Caution See label
Max: See label (2 lbs ai) 
7 5 days Do not mix with any Captan product.  See label for dilute vs. concentrated spray… Make 1st application when sprouts are 0.25-0.5 inch, 2nd application when sprouts are 0.5-1 inch. Avoid applying when bees are present.
Human & Environment: NS, 11 day persistence
SL, SRW, SWD  B1
F1
SWD 3
Entrust SC
(OMRI expires 03/1/21)
spinosad
Group 5
4 to 6 oz
Max: 6 app, 3 for thrips
29 oz (0.45 lb ai total for all spinosad)
1 4 hrs Allowed for Organic production. Toxic to bees up to 3 hrs following treatment. Once it dries on foliage, toxicity is LOW. Apply at least 6 days apart; after 2nd application rotate to products other than Group 5. May be used with adjuvants. See supplemental label for reduced PHI for SWD suppression.
Human & Environment: NS, 1.5 day persistence
BMF B1
F1
GF-120 NF Naturalyte Fruit Fly Bait
(OMRI expires 12/1/20)
spinosad
Group 5
Caution 10 to 20 oz
1:1.5 product to water ratio
Max: 5 app; 0.45 lb ai total for all spinosad
0 4 hrs Allowed for Organic production. Specialized application equipment is required. Apply every 7-14 days. Do not rotate with other Group 5 products. Toxic to bees if sprayed directly.
Human & Environment: NS, 1.5 day persistence
BMF, SWD P2
B1
SWD 3
Exirel  cyantraniliprole Group 28 Caution 13.5 to 20.5
Max: 62 oz (0.4 lb ai) 
3 12 hrs Rotate with products with different modes of action; minimum interval between treatments is 5 days. Direct contact and exposure to residue is toxic to bees.
Human & Environment: S, 14 day persistence
BMF, SL, FB, SRW, SWD  P2
B1
F1
SWD 4
Imidan 70-W phosmet
Group 1B
Warning 1.3 lbs; aerial ULV 2 GPA water
(1.3 lb SWD)
Max: 5 app; 5 1/8 lb (3.63 lb ai) for all phosmet
3 3 days Apply at 7-10 day intervals. Highly toxic to bees if sprayed or come into contact with treated foliage up to 7-10 days after spraying so do not spray 10-14 days PRIOR to bloom.
Human & Environment: NS, 10 day persistence
SL     Intrepid 2F methoxyfenozide
Group 18
Caution 10 to 16 oz
Max: 3 app;
48 oz (0.75 lb ai)
7 4 hrs Caterpillar control. Do not apply more than once every 7 days. Spreaders/binders may help maximize coverage. Can use just prior to bloom without detrimental effects on bees. Drift and runoff from applications of this product may be hazardous to sensitive aquatic invertebrates in water bodies adjacent to treatment area.
Human & Environment: NS, 15 day persistence
SWD, Thrips  
 
P2
B1
F1
D2
SWD 3
Malathion
(several formulations registered)
malathion
Group 1B
Warning See label
Max: —-
1 12 hrs Minimum retreatment interval is 5 days. Apply at 10 day intervals for BMF. High runoff potential after application. Highly toxic to bees if sprayed directly.
Human & Environment: NS, 3 day persistence
Malathion 8F, 8 Aquamul
(24c expires 12/31/23)
UP to 40 oz SWD
Max: 2 app SWD (5 lb ai)
7 day minimum intervals for SWD. Potential for phytotoxicity at reduced rates. See label for dilute vs. concentrated spray. Highly toxic to bees if sprayed directly. See 24C label for SWD control.
Human & Environment: NS, 3 day persistence
BMF, SWD, Thrips B1
D1
SWD 2 
Montana 2F imidacloprid
Group 4A
Caution Foliar 4.8 to 6.4 oz
Max: Foliar 5 app; 32 oz (0.5 lb ai) for all
3 12 hrs Foliar: Apply at least 7 days apart. Rotate to another mode of action after 3 applications.  Do not apply foliar after applying a soil application of any Group 4A product. Avoid prior to and during bloom. Highly toxic to bees. Sprout application during emergence for thrips; make 1st application when sprouts are 0.25-0.5 inch, 2nd application when sprouts are 0.5-1 inch.
Human & Environment: S, 7 day persistence
Montana 4F Foliar 2.4 to 3.2 oz
Max: Foliar 5 app;16 oz
(0.5 lb ai)
SWD P2
B1
F1
SWD 4
Mustang Maxx zeta-cypermethrin
Group 3A
Warning 4 oz
(4 oz SWD)
Max: 24 oz (0.15 lb ai)
1 12 hrs Apply at least 7 days apart. See 2ee labels for BMF (suppression only) and SWD. Direct spray and residue is highly toxic to bees, do not use prior or during bloom.
Human & Environment: NS, 21 day persistence
BMF, SWD B1
F2
SWD 2
Sevin
Several formulations registered
carbaryl
Group 1A
Warning See label
Max: 5 applications;
10 qts
7 12 hrs Do not apply more than once every 7 days.  Do not apply during bloom or just prior to bloom; high toxicity to bees.  Avoid irrigation for 48 hrs post-application. Flea beetle adults only.
Human & Environment: NS, 7 day persistence
BMF, Thrips P2
B2
Sivanto 200 SL Flupyradifurone
Group 4D
Warning 10.5 to 14 oz
Max: 28.0 oz (0.365 lb ai).
0 4 hrs Apply at least 10 days apart.  See 2ee label for thrips. Human dermal toxicity is moderate.
Human & Environment: S

Prepared by Jennifer D’Appollonio, Assistant Scientist; David E. Yarborough, Extension Blueberry Specialist; Phil Fanning, Professor of Agricultural Entomology and Judith Collins, Assistant Scientist the University of Maine, Orono, ME 04469.  February 2020. *Please note: This revised version replaces any previous charts. *

Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

© 2020

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