Spotted Wing Drosophila Alert: August 17, 2017

August 18th, 2017 1:30 PM
Insects in Spotted Wing Drosophila Trap

Insects in Spotted Wing Drosophila Trap, Male SWD Circled, photo by Kaytlin Woodman

SPOTTED WING DROSOPHILA ALERT: AUGUST 17, 2017

Click on photos to enlarge.

David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Spotted wing drosophila trap captures have increased significantly at most locations over the past two weeks. (See table below.) All of the trapping sites are catching numbers that will result in significant infestations of larvae in any ripening soft fruit, especially raspberries, blackberries, blueberries and day-neutral strawberries. Peaches, nectarines and plums may also be susceptible, especially if the fruit have any growth or stem cracks. At this point, a spray schedule of 5 to 7 days apart should be adequate to prevent fruit infestation.

Spotted Wing Drosophila Larvae in Raspberry

Spotted Wing Drosophila Larvae in Raspberry, photo by David Handley

Spotted wing drosophila (SWD) populations are likely to continue rising as more fruit, especially waste fruit becomes available to the flies. Continue to look for fruit flies hovering around fruit and symptoms of premature fruit decay. The flies favor shady, moist regions of the planting. Be sure your insecticide sprays penetrate the outer foliage to reach the interior of the plants. Harvest regularly and often to prevent the buildup of overripe fruit and remove all rotten or cull fruit from the field. Pruning out excessive vegetative growth that provides shade and cover for the flies can also help reduce infestations and improve spray penetration.

Other IPM Web Pages
Michigan State University
Penn State University
University of New Hampshire

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME 04259          Orono, ME 04473
207.933.2100                           1.800.287.0279

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

Town Spotted Wing  Drosophila weekly trap catch 8/3/17 Spotted Wing  Drosophila weekly trap catch 8/10/17 Spotted Wing  Drosophila weekly trap catch 8/16/17
Wells 12 11 41
Sanford 8 4 115
Limington 233 678 517
Limerick 19 25 159
Cape Elizabeth 65 786 830
Buxton 14 37 455
New Gloucester 780 1534 554
Bowdoinham 128 130 402
Dresden 47 111 130
Freeport 3 17 50
Poland Spring 22 10 96
Mechanic Falls 0 1 24
Monmouth 2 17 57
Wales 85 429
Farmington 123 272
Fayette 8 37 117

Sweet Corn IPM Newsletter No. 9 – August 18, 2017

August 18th, 2017 10:59 AM

Sweet CornSweet Corn IPM Newsletter No. 9 – August 18, 2017
Click on photos to enlarge.

COOL NIGHTS SLOW INSECT ACTIVITY  

Silking Corn Still Needs Protection in Most Fields

SITUATION
Cool nights and dry conditions have slowed corn development, and pushed expected harvests dates back, leading to a short supply of sweet corn in some areas. Expected rain over the weekend and warmer temperatures next week should help the situation. Insect pressure has been somewhat lighter this week, although most fields still require protection for silking corn.

European corn borer:  Moth counts have been spotty around the state.  Most locations continue to see no moths, but counts have increased in a few fields. Fields in North Berwick and Poland Spring were over the 5-moth threshold for silking corn, but both sites are also under a spray interval for corn earworm, so no additional sprays should be needed. Larval feeding injury was low, with most of the injury on late corn due to fall armyworm.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Corn earworm:  Moth counts were generally lower in most locations this week, but still high enough to warrant a tight spray schedule for silking corn in most fields. A 6-day spray interval for corn earworm was recommended for silking fields in Wayne. A 5-day spray schedule was recommended in Bowdoinham, one Cape Elizabeth site, Levant, Poland Spring and one Wells site. A 4-day spray interval was recommended in Auburn, one Cape Elizabeth site, Lewiston, New Gloucester, Nobleboro, North Berwick, Sabattus and one Wells site.

Male Fall Armyworm Moth

Male Fall Armyworm Moth, photo by David Handley

Fall armyworm:  Similar to corn earworm, moth counts were mostly lower this week, although several sites were over the 3-moth threshold for silking corn. A spray for fall armyworm on silking corn was recommended in Biddeford.  Other sites, including Cape Elizabeth, New Gloucester, Nobleboro, Poland Spring, and Wells were also over the 3-moth threshold, but are now on a spray schedule for corn earworm. Larval feeding damage in younger corn was also lower this week. Fields in Auburn, Cape Elizabeth, New Gloucester, Poland Spring and Wells were over the 15% injury threshold, and sprays for pre-tassel to tassel corn were recommended.

Potato Leafhopper

Potato Leafhopper, photo by James Dill

Potato leafhopper alert:  We are still seeing signs of potato leafhopper in vegetable and strawberry fields this week. These small, green bullet-shaped insects feed on plant sap from the undersides of leaves, causing the leaves to become curled, stunted and yellow-streaked. Beans are often the first crop to show symptoms, but other crops are also susceptible, including potatoes and strawberries. Controls for potato leafhoppers are listed in the New England Vegetable Management Guide.

Squash vine borer:  Counts were quite low this week, with no fields over the control threshold, which agrees with data from NH. There is the possibility of a second generation emerging over the next few weeks that could threaten late squash and pumpkins or attack ripening fruit.

Spotted Wing Drosophila Larvae in Blueberry

Spotted Wing Drosophila Larvae in Blueberry, photo by David Handley

Spotted wing drosophila: Numbers have been increasing over the past week, and now threaten any soft fruit in the field, such as late raspberries and blueberries. Regular sprays will be needed to prevent such fruit from becoming infested with larvae. Visit our Spotted Wing Drosophila blog for more information.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259         Orono, ME  04473
207.933.2100                           1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW

Moths

ECB

Moths

FAW

Moths

%Feeding

Damage

Recommendations / Comments
Auburn 18 0 2 47% 4-day spray interval recommended on all silking corn
Biddeford 0 0 3 2% One spray recommended for FAW
Bowdoinham 5 0 2 7% 5-day spray interval recommended on all silking corn
Cape Elizabeth I 6 1 0 20% 5-day spray interval recommended on all silking corn
Cape Elizabeth II 8 9 4-day spray interval recommended on all silking corn
Charleston 1 1 0 No spray recommended
Dayton 5 1 1 1% 5-day spray interval recommended on all silking corn
Farmington 0 0 0 5% No spray recommended
Lewiston 8 1 1 4-day spray interval recommended on all silking corn
Garland 0 2 0 3% No spray recommended
Levant 5 2 3 2% 5-day spray interval recommended on all silking corn
Monmouth 0 0 1 14% No spray recommended
New Gloucester 30 0 28 16% 4-day spray interval recommended on all silking corn
Nobleboro 12 1 3 4-day spray interval recommended on all silking corn
North Berwick 15 5 1 3% 4-day spray interval recommended on all silking corn
Oxford 0 0 1 0% No spray recommended
Palmyra 0 0 1 0% No spray recommended
Poland Spring 6 9 15 20% 5-day spray interval recommended on all silking corn
Sabattus 10 0 0 0% 4-day spray interval recommended on all silking corn
Wales 1 0 0 0% No spray recommended
Wayne 3 0 0 6-day spray interval recommended on all silking corn
Wells I 6 0 2 25% 5-day spray interval recommended on all silking corn
Wells II 9 0 11 5% 4-day spray interval recommended on all silking corn

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages :
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM Programs

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

Sweet Corn IPM Newsletter No. 8 – August 11, 2017

August 11th, 2017 2:24 PM

Sweet CornSweet Corn IPM Newsletter No 8 – August 11, 2017

Click on photos to enlarge.

CORN EARWORM THREAT INCREASES  

Fall Armyworm, European Corn Borer Also Increases

SITUATION
A little bit of rain over most of the state helped move corn along, but cooler weather recently has delayed development of younger fields. Harvest is moving into main season varieties and quality continues to look good. Corn earworm numbers are up significantly in most locations, calling for a tightening of spray intervals.

European corn borer:  Moth counts have increased in some fields this week, suggesting that a second generation of European corn borer may be getting underway in southern Maine, but feeding injury remains low, and most fields are presently being protected with sprays for corn earworm.

Corn earworm:  Moth counts increased significantly in many locations this week, requiring a tightening of spray intervals for silking corn fields. A 6-day spray interval for corn earworm was recommended for silking fields in Monmouth and one Dayton site. A 4-day spray interval was recommended in Auburn, Biddeford, Bowdoinham, one Cape Elizabeth site, one Dayton site, Lewiston, North Berwick, Poland Spring, Wales, and Wells. A 3-day spray interval was recommended at one of the Cape Elizabeth sites.

Corn Earworm Larvae

Corn Earworm Larvae, photo by David Handley

Fall Armyworm on Corn Leaf

Fall Armyworm on Corn Leaf, photo by David Handley

 Fall armyworm:  Moth counts are still fairly high, and increased at several sites. Most fields are presently under a spray interval for corn earworm, however, so the silking fields should be adequately protected. A spray for fall armyworm on silking corn was recommended in Oxford.  Other sites, including Auburn, Lewiston, Biddeford, Cape Elizabeth, Dayton, Monmouth, New Gloucester, Wales and Wells were also over the 3-moth threshold, but are now on a spray schedule for corn earworm.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259         Orono, ME  04473
207.933.2100                           1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 17 0 15 46% 4-day spray interval recommended on all silking corn
Biddeford 36 1 11 6% 4-day spray interval recommended on all silking corn
Bowdoinham 11 0 0 1% 4-day spray interval recommended on all silking corn
Cape Elizabeth I 33 1 15 43% 4-day spray interval recommended on all silking corn
Cape Elizabeth II 118 3 22 38% 3-day spray interval recommended on all silking corn
Dayton I 2 0 0 6-day spray interval recommended on all silking corn
Dayton II 37 0 7 11% 4-day spray interval recommended on all silking corn
Farmington 0 0 0 0% No spray recommended
Lewiston 24 2 9 1% 4-day spray interval recommended on all silking corn
Monmouth 3 0 6 6% 6-day spray interval recommended on all silking corn
New Gloucester 49 One spray recommended for FAW on pre-tassel corn
North Berwick 38 6 2 2% 4-day spray interval recommended on all silking corn
Oxford 1 0 4 0% One spray recommended for FAW
Poland Spring 18 8 2 12% 4-day spray interval recommended on all silking corn
Wales 8 0 6 0% 4-day spray interval recommended on all silking corn
Wells I 8 0 6 31% 4-day spray interval recommended on all silking corn
Wells II 71 0 8 0% 4-day spray interval recommended on all silking corn

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages :

UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM Programs

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

 

Spotted Wing Drosophila Alert: August 3, 2017

August 4th, 2017 3:01 PM
Spotted Wing Drosophila Trap Catch

Spotted Wing Drosophila Trap Catch, photo by Christina Hillier

SPOTTED WING DROSOPHILA UPDATE: AUGUST 3, 2017

Click on photos to enlarge.

David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Spotted wing drosophila activity continues to increase at most trapping sites this week. (See table below.) Most of the trap counts are above what we consider potentially damaging to ripening berry crops, especially raspberries, blackberries and blueberries. Research suggests that when 6 to 10 flies are caught in a yeast-baited trap in a week, larvae will start appearing in the fruit. At this point, a spray schedule of 7 to 10 days apart should be adequate to prevent fruit infestation at most locations. However, at sites where higher populations are now occurring (New Gloucester, Farmington, Limerick, Bowdoinham), fruit may need to be under a five to seven-day spray interval to achieve adequate protection.

Spotted Wing Drosophila on Raspberry

SWD on Raspberry, photo by David Handley.

Spotted wing drosophila (SWD) populations are likely to continue rising in the coming weeks. Look for fruit flies hovering around fruit and symptoms of premature fruit decay. Remember, the flies favor shady, moist regions of the planting. Flies can be discouraged by harvesting regularly to prevent the buildup of overripe fruit, removing all rotten or cull fruit from the field, and pruning out excessive vegetative growth that provides shade and cover for the flies.

 

Other IPM Web Pages
Michigan State University
Penn State University
University of New Hampshire

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME 04259          Orono, ME 04473
207.933.2100                           1.800.287.0279

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

Town Spotted Wing  Drosophila weekly trap catch 7/20/17 Spotted Wing  Drosophila weekly trap catch 7/27/17 Spotted Wing  Drosophila weekly trap catch 8/3/17
Wells 8 12 12
Sanford 6 16 8
Limington 7 21 233
Limerick 4 18 19
Cape Elizabeth 37 68 65
Buxton 3 5 14
New Gloucester 298 600 780
Bowdoinham 28 74 128
Dresden 2 13 47
Freeport 4 10 3
Poland Spring 2 4 22
Mechanic Falls 0 0
Monmouth 5 1 2
Wales 121 78 85
Farmington 9 141 123
Fayette 5 7 8

Sweet Corn IPM Newsletter No. 7 – August 4, 2017

August 4th, 2017 1:43 PM

Sweet Corn

Sweet Corn IPM Newslettter No. 7 – August 4, 2017
Click on photos to enlarge.

INCREASING CORN EARWORM ACTIVITY  

Fall Armyworm Threat Remains High in Many Fields

SITUATION
“Abnormally dry” conditions continue in much of the state, and growers are spending a lot of time keeping up with irrigation.  Harvest is progressing on early corn and overall quality looks good. Corn earworm populations have increased a bit over last week, and fall armyworm numbers are high in some fields.

European corn borer:  Moth captures were very low this week, suggesting an end to the first generation of this pest. Larval feeding activity was also very low and did not exceed threshold in any fields.

Corn earworm:  Moth counts increased moderately in most locations this week, putting most fields on a spray interval for silking corn. A 6-day spray interval for corn earworm was recommended for silking fields in Auburn, one Cape Elizabeth site, one Dayton site, Lewiston, Levant, Nobleboro, Palmyra, Poland Spring, and one Wells site. A 5-day spray interval was recommended for silking fields at one Dayton site and New Gloucester. A 4-day spray interval was recommended in Biddeford, one Cape Elizabeth site and Garland.

Corn Earworm

Corn Earworm, photo by David Handley

Fall Armyworm on Corn Silk

Fall Armyworm on Corn Silk, photo by David Handley

Fall armyworm:  Moth counts are down a bit from last week, however counts are still very high at some locations and present a significant threat to both young plants and silking corn. Most silking fields are now under a spray interval for corn earworm, which should also keep fall armyworm in check. However, in silking fields that are not currently spraying for earworm, weekly applications for fall armyworm based on the three moths caught per week threshold, may not provide adequate protection, especially under hot, dry conditions; and growers should consider more frequent applications. A spray for fall armyworm on silking corn was recommended in Sabattus.  Other sites, including Auburn, Lewiston, Biddeford, Cape Elizabeth, Dayton, New Gloucester, Nobleboro, and Wells were also over the 3-moth threshold, but are now on a spray schedule for corn earworm.

Powdery Mildew on Pumpkin Leaf

Powdery Mildew on Pumpkin Leaf, photo by Mark Hutton

Squash vine borer moths were above the spray threshold of 5 moths in Biddeford, Cape Elizabeth and New Gloucester this week. Growers with squash and pumpkins should be on the lookout for vine borer symptoms and protect squash plants if moths or damage are seen.

We are also starting to see more disease pressure in squash and pumpkins. Both powdery mildew and black rot (aka gummy stem blight) have starting appearing in pumpkin fields this week. For management suggestions check the New England Vegetable Management Guide. If you need a copy please call us, or you can find it online at: https://nevegetable.org/.

Squash Vine Borer Larva

Squash Vine Borer Larva, photo by Jeffrey Hahn, Univ. of Minnesota Extension

Spotted Wing Drosophila Larvae in Raspberry

Spotted Wing Drosophila Larvae in Raspberry, photo by David Handley

Spotted wing drosophila:  Fly counts have been rising over the past week, and most sites are now at a level where control measures are required to prevent infestation. Blueberries, raspberries and blackberries are especially at risk, and should be sprayed at a 5- to 7-day interval to maintain clean fruit. For details, visit our Spotted Wing Drosophila blog.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259         Orono, ME  04473
207.933.2100                           1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 2 0 52 0% 6-day spray interval recommended on all silking corn
Biddeford 13 0 8 31% 4-day spray interval recommended on all silking corn
Bowdoinham 1 0 0 1% No spray recommended
Cape Elizabeth I 2 0 8 2% 6-day spray interval recommended on all silking corn
Cape Elizabeth II 9 0 21 4-day spray interval recommended on all silking corn
Charleston 0 1 1 1% No spray recommended
Dayton I 4 0 1 0% 5-day spray interval recommended on all silking corn
Dayton II 2 0 7 3% 6-day spray interval recommended on all silking corn
Farmington 0 2 0 0% No spray recommended
Garland 8 0 0 0% 4-day spray interval recommended on all silking corn
Lewiston 2 0 6 0% 6-day spray interval recommended on all silking corn
Levant 3 0 0 0% 6-day spray interval recommended on all silking corn
New Gloucester 5 0 73 0% 5-day spray interval recommended on all silking corn
Nobleboro 2 0 6 2% 6-day spray interval recommended on all silking corn
North Berwick 0 0 0 0% No spray recommended
Oxford 0 2 17% One spray recommended for FAW on pre-tassel corn
Palmyra 3 0 0 0% 6-day spray interval recommended on all silking corn
Poland Spring 2 1 0 37% 6-day spray interval recommended on all silking corn
Sabattus 1 0 6 2% One spray recommended for FAW on all silking corn
Wales 1 0 1 0% No spray recommended
Wayne 0 1 0 0% No spray recommended
Wells I 2 0 8 0% 6-day spray interval recommended on all silking corn
Wells II 0 0 0 0% No spray recommended

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths
caught in pheromone traps in one week.

IPM Web Pages:
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM Programs

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

Sweet Corn IPM Newsletter No. 6 – July 31, 2017

July 31st, 2017 2:06 PM

Sweet CornUniversity of Maine Sweet Corn IPM Newsletter No. 6 – July 31, 2017
Click on photos to enlarge.

FALL ARMYWORM PRESSURE INCREASES  

New Pest of Onions, Garlic and Leeks Found in Western Maine

SITUATION
Many parts of the state are experiencing very dry conditions, but corn that can be irrigated is progressing well. Corn earworm populations remain very moderate at most sites, and European corn borer numbers are also low in most fields. Fall armyworm numbers continue to rise in most fields, however. A new pest of onions, garlic and leeks has recently been found in Maine. Leek moth may become a problem for crops in the allium group.

European corn borer:  Moth captures continue to be low in nearly all locations this week. Larval feeding activity also remained under threshold. We typically see a drop in corn borer activity in the mid-summer, as the larvae from the first generation begin to pupate. However, this may lead to a second generation late in the summer, especially in southern Maine.

Corn earworm:  Moth counts remain moderate in most locations this week, with less than half of the trapping sites exceeding a spray threshold. This is less pressure than we typically see at this point in the season. A 6-day spray interval for corn earworm was recommended for silking fields in Levant, Nobleboro, Wales and one Wells site this week. A 5-day spray interval was recommended for silking fields in Garland and Poland Spring. A 4-day spray interval was recommended in Auburn and Lewiston.

Fall Armyworm Eggs on Corn

Fall Armyworm Eggs on Corn, photo by David Handley

Fall armyworm:  Moth counts have risen at nearly all trap locations this week, indicating that this pest is presently the most significant threat to corn for most growers. When more than three moths are caught in a week in silking corn, a spray is recommended to prevent larvae from infesting the ears, unless the field is under a spray interval for corn earworm. Sprays for fall armyworm on silking corn were recommended in Biddeford, Cape Elizabeth, Dayton, Farmington, New Gloucester, North Berwick, Oxford, Wayne and one Wells site this week. Auburn, Lewiston, Nobleboro and Wales were also over the 3-moth threshold, but are under a spray schedule for corn earworm.

Leek Moth is a “new” pest of allium crops, including onions, garlic, shallots and leeks. Native to Europe, it was first found in New York in 2009, and has been spreading throughout the northeast. The adult moth is ½-inch long, speckled brown with a white spot on the wings. It is active at night, so is not commonly seen. They lay eggs on the undersides of allium leaves. The larvae are small (3/8-inch) creamy yellow caterpillars that feed on the leaves, leaving translucent channels between the leaf veins. The feeding weakens the plants and allows rot organisms to move in, which can affect the quality and storage life of the bulbs. Leek moths have been caught in pheromone traps in western Maine. We do not yet have any reports of crop damage, but we recommend that you scout your allium crops and let us know if you see any suspected injury. An excellent web site has been set up for leek moth by Cornell University at:  http://web.entomology.cornell.edu/shelton/leek-moth/index.html.

Leek moth adult

Leek Moth Adult, photo by Dan Olmstead, Cornell University

Squash Vine Borer Larva

Squash Vine Borer Larva, photo by David Handley

Squash vine borer moths were above the spray threshold in Biddeford, Cape Elizabeth, and Oxford this week.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259         Orono, ME  04473
207.933.2100                           1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 8 1 7 1% 4-day spray interval recommended on all silking corn
Biddeford 1 2 51 4% One spray recommended for FAW on all silking corn
Bowdoinham 0 0 0 6% No spray recommended
Cape Elizabeth I 1 0 29 2% One spray recommended for FAW on all silking corn
Cape Elizabeth II 0 41 One spray recommended for FAW on all silking corn
Charleston 0 0 2 0% No spray recommended
Dayton I 0 0 9 One spray recommended for FAW on all silking corn
Dayton II 7 0 39 4% 5-day spray interval recommended on all silking corn
Farmington 1 2 3 1% One spray recommended for FAW on all silking corn
Garland 4 0 0 2% 5-day spray interval recommended on all silking corn
Lewiston 11 0 31 1% 4-day spray interval recommended on all silking corn
Levant 2 2 0 1% 6-day spray interval recommended on all silking corn
New Gloucester 1 0 106 5% One spray recommended for FAW on all silking corn
Nobleboro 2 0 13 6-day spray interval recommended on all silking corn
North Berwick 1 1 9 5% One spray recommended for FAW on all silking corn
Oxford 1 0 15 0% One spray recommended for FAW on all silking corn
Palmyra 1 5 0 0% No spray recommended (no silking corn)
Poland Spring 4 0 1 5-day spray interval recommended on all silking corn
Wales 3 3 4 0% 6-day spray interval recommended on all silking corn
Wayne 1 0 3 4% One spray recommended for FAW on all silking corn
Wells I 0 0 11 0% One spray recommended for FAW on all silking corn
Wells II 0 0 9 2% One spray recommended for FAW on all silking corn

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM Programs

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

Sweet Corn IPM Newsletter No. 5 – July 21, 2017

July 24th, 2017 10:54 AM

Sweet CornSweet Corn IPM Newslettter No. 5 – July 21, 2017
Click on photos to enlarge.

Highmoor Farm Field Day
Wednesday, July 26, 2017
Save the Date!

INSECT PRESSURE HIGHER; PROTECT SILKING CORN

Corn Earworm & Fall Armyworm Numbers Increasing

SITUATION
High temperatures have pushed sweet corn development, compensating somewhat for earlier cool temperatures.  While European corn borer pressure has been decreasing, corn earworm and fall armyworm pressure has been increasing, posing a serious risk to fields now in silk. Synthetic pyrethroid insecticides (FRAC Group 3A) may have a short residual life under hot, sunny conditions, so recommended spray intervals should not be extended unless daily high temperatures fall below 85 degrees for 3 or more consecutive days. For those growers trying Bt-modified corn selections, it is important to note that this protection may not be adequate under very heavy fall armyworm or corn earworm pressure. When moth populations are high, Bt fields should be scouted for injury and treated if necessary.

European corn borer:  Moth captures were very low this week, and larval feeding activity is decreasing. No fields were over the recommended spray thresholds. However, fall armyworm larval feeding damage is being noticed in more fields, and is quickly become more of a threat than European corn borer.

Corn earworm:  Moth counts increased again this week, and are becoming more widely distributed. More silking fields have been put on spray schedules to protect ears from infestation. A 6-day spray interval for corn earworm was recommended for silking fields in Oxford, Sabattus, Dayton, North Berwick and one Wells site this week. A 5-day spray interval was recommended for silking fields in Auburn, Cape Elizabeth, Garland, and Poland Spring. A 4-day spray interval was recommended in Lewiston.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Fall Armyworm Moths

Fall Armyworm Moths (female right, male left), photo by James Dill

 Fall armyworm: Moth counts rose significantly in many locations this week, indicating that fall armyworm will be an important threat to corn in the coming days and weeks. Feeding damage was found in more fields, but has generally been low to date. Once the corn has reached the silking stage, sprays should be based on captures of moths in pheromone traps to prevent larvae from damaging the ears. If three or more moths are caught in a week in silking fields, a spray is recommended, unless the field is under a spray interval for corn earworm. Sprays for fall armyworm on silking corn were recommended in Biddeford New Gloucester, Wayne and one Wells site this week. Cape Elizabeth and Lewiston were also over the 3-moth threshold, but are under a spray schedule for corn earworm.

Spotted wing drosophila:  Fly counts have risen significantly in most of our trapping sites this week. Growers with ripening blueberries, raspberries or other soft fruit should be monitoring for flies and larvae, and should consider protecting all ripening fruit. For details, visit our Spotted Wing Drosophila blog.

Male and Female Spotted Wing Drosophila

Male and Female Spotted Wing Drosophila, image by Alan Kenage, Capital Press

Two Squash Vine Borer Moths

Two Squash Vine Borer Moths, photo by Jeffrey Hahn, Univ. of Minnesota Extension

Squash vine borer moths were caught in pheromone traps in Wells, Biddeford, Cape Elizabeth, Farmington and Oxford this week. The Biddeford, Cape Elizabeth and Dayton sites were above the 5 moths per week spray threshold, and a spray was recommended. This pest remains active in much of the state. Growers with squash and pumpkins should be on the lookout for vine borer symptoms and protect squash plants if moths or damage are seen.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259         Orono, ME  04473
207.933.2100                           1.800.287.0279

 

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 5 0 0 0% 5-day spray interval recommended on all silking corn
Biddeford 0 31 12% One spray recommended for FAW on all silking corn
Cape Elizabeth I 4 0 6 0% 5-day spray interval recommended on all silking corn
Cape Elizabeth II 6 0 26 10% 5-day spray interval recommended on all silking corn
Charleston 0 0 0 0% No spray recommended
Dayton I 3 1 1 6-day spray interval recommended on all silking corn
Dayton II 1 0 1 5% No spray recommended
Farmington 1 1 2 2% No spray recommended
Garland 4 0 0 0% 5-day spray interval recommended on all silking corn
Lewiston 9 0 29 0% 4-day spray interval recommended on all silking corn
Levant 1 0 0 1% No spray recommended
New Gloucester 0 0 41 0% One spray recommended for FAW on all silking corn
Nobleboro 1 0 0 0% No spray recommended
North Berwick 3 1 1 2% 6-day spray interval recommended on all silking corn
Oxford 2 0 11 9% 6-day spray interval recommended on all silking corn
Palmyra 3 0 0 0% No spray recommended (no silking corn)
Poland Spring 6 0 0 5-day spray interval recommended on all silking corn
Sabattus 2 0 0 3% 6-day spray interval recommended on all silking corn
Wales 0 0 1 0% No spray recommended
Wayne 1 0 6 0% One spray recommended for FAW on all silking corn
Wells I 1 2 9 1% One spray recommended for FAW on all silking corn
Wells II 3 0 3 1% 6-day spray interval recommended on all silking corn

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:
UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM Programs

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

 

 

Spotted Wing Drosophila Alert: July 21, 2017

July 21st, 2017 1:48 PM
Male and Female Spotted Wing Drosophila

Male and Female Spotted Wing Drosophila, image by Alan Kenage, Capital Press

SPOTTED WING DROSOPHILA ALERT: JULY 21, 2017

Click on photos to enlarge.

David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

There has been an increase in spotted wing drosophila activity at most trapping sites this week (see table below). Reports from throughout the northeast suggest a similar trend. This is significantly earlier activity than we have seen in recent years, and some of the trap counts are already well above what we consider potentially damaging to ripening berry crops, especially raspberries and blueberries.  Research suggests that when 6 to 10 flies are caught in a yeast-baited trap in a week, larvae will start appearing in the fruit.

We expect that spotted wing drosophila populations (SWD) will continue to build rapidly in the coming weeks as more eggs are laid in the fruit that is now ripening. Growers should set out traps, if you haven’t already. Start protective sprays on any berries that have begun to ripen when more than four spotted wing drosophila flies are caught in a trap, or any larvae are noticed in the fruit. Look for fruit flies hovering around fruit and symptoms of premature fruit decay. Remember, the flies favor shady, moist regions of the planting.

Insects in Spotted Wing Drosophila Trap

Insects in Spotted Wing Drosophila Trap, Male SWD Circled, photo by Kaytlin Woodman

You can find directions for making a home-made SWD monitoring trap on our SWD blog. An effective commercial trap and bait is now available from Scentry.  The trap is reusable and the bait lasts 4-6weeks.  Cost for both is about $15 plus shipping, it is available from Great Lakes IPM Company (http://www.greatlakesipm.com/).

Other IPM Web Pages
Michigan State University
Penn State University
University of New Hampshire

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME 04259          Orono, ME 04473
207.933.2100                           1.800.287.0279

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

 

Town Spotted Wing Drosophila weekly trap catch 7/6/17 Spotted Wing  Drosophila weekly trap catch 7/13/17 Spotted Wing  Drosophila weekly trap catch 7/20/17
Wells 19 8
Sanford 0 4 6
Limington 4 2 7
Limerick 1 3 4
Cape Elizabeth 19 21 37
Buxton 12 6 3
New Gloucester 3 30 298
Bowdoinham 2 10 28
Dresden 0 0 2
Freeport 2 0 4
Poland Spring 1 2 2
Mechanic Falls 14 5 0
Monmouth 2 4 5
Wales 110 121
Farmington 0 3 9
Fayette 6 3 5

 

 

 

 

Spotted Wing Drosophila Alert: July 17, 2017

July 17th, 2017 2:48 PM
Male Spotted Wing Drosophila

Male Spotted Wing Drosophila, photo by Griffin Dill. Actual size: 2-3 mm.

SPOTTED WING DROSOPHILA ALERT: JULY 17, 2017

Click on photos to enlarge.

David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

We have found numerous spotted wing drosophila (SWD) fruit flies in raspberry and highbush blueberry plantings in Maine over the past week, in nearly every location that we have set up traps (see table below). This information compliments reports from throughout the northeast that SWD is active and in higher numbers much earlier than we have seen in recent years.

Some of the fly counts are already well above what we would consider potentially damaging to ripening berry crops, especially raspberries and blueberries. Research in Maine and other regions suggests that when 6 to 10 flies are caught in a yeast-baited trap in a week, larvae will start appearing in the fruit.

Spotted wing drosophila populations are likely to build rapidly in the coming weeks as more food (fruit) becomes available for the flies, especially if conditions remain warm and we get some rain. Now is the time to set out traps, if you haven’t already. Start protective sprays on any berries that have begun to ripen, when more than four spotted wing drosophila flies are caught in a trap, or any larvae are noticed in the fruit. Look for fruit flies hovering around fruit and symptoms of premature fruit decay.

Research has shown that dry conditions and exposure reduce the number of eggs these insects will lay in the fruit. This supports our recommendations to open up your berry plantings by pruning, especially low growth, as these insects favor dark, moist conditions, close to the ground.

Based on what we know so far about this pest, here are six rules for managing spotted wing drosophila.

  1. Monitor for the flies with traps, and for the larvae in fruit.
  2. Spray regularly and often once flies have been found in the field (1-2/week).
  3. Harvest fruit regularly and often; do not leave any ripe/rotten fruit in the field.
  4. Sort fruit at harvest; do not leave any soft fruit in the container to be sold.
  5. Chill all fruit immediately after harvest to 38ºF (or as close as you can) for at least 12 hours to slow development of any eggs or larvae.
  6. Prune the planting to open up the canopy and create dry, light conditions.

Products that provide good control of drosophila on berry crops include spinosad (Radiant® for strawberries, Delegate® for raspberries and blueberries), Asana®, Brigade®, Danitol®, malathion, Exirel® (blueberries only) and Assail®. Research suggests that adding table sugar to group 4A insecticides, such as Assail®, may improve their effectiveness. The recommended rate would be 1-2 lbs. sugar per 100 gallons of spray. Please check product labels for rates, post-harvest intervals and safety precautions. Keeping fields clean of overripe and rotten fruit will also help reduce the incidence of this insect.

Characteristics of Insecticides for Spotted Wing Drosophila Control

Trade Name Days to Harvest
Blueberry
Days of Residual
Assail® 1 5-7
Mustang Max® 1 7
Bifenture® 1 (3 raspberry) 7
Brigade® 1 (3 raspberry) 7
Danitol® 3 7
Delegate® 3 (1 raspberry) 7
Entrust® 3 (1 raspberry) 3-5
Exirel® 3 (not for raspberry) 5-7
Imidan® 3 (not for raspberry) 5-7

 

drosophila trap

Drosophila Trap, photo by David Handley

A Simple Monitoring Trap for Spotted Wing Drosophila

The trap body is made from a 16 ounce red plastic cup (we use Solo Brand P16RLR). You’ll need one that has a tight fitting lid (we use Solo Brand 626TS). Using a 1/8” hole punch (available through art suppliers), punch about 15 holes in a row around the cup just under the lip about 1/2” apart. Leave about 2” of the diameter of the rim with no holes so that liquid can be poured in and out. Punch a second row of holes just under the first row, to give you a total of 30, 1/8” holes. Use a black permanent marker to paint a 1/2” wide black strip around the cup under the rim, right over the holes you punched. To support the trap, cut a wooden tomato stake down to about 30”. Attach a 4” or larger hose clamp near the top of the stake to act as a cup holder for the trap. (We just punched a hole in the metal band of the hose clamp and attached it to the stake with a flat-headed wood screw.) Place the trap holder in a shady, moist place in or near the fruit planting, with the cup height about 18” off the ground. Fill the trap with 4 to 6 ounces of apple cider vinegar, water + sugar + yeast, or whatever bait you prefer. It is best to add a few drops of unscented soap to break the surface tension of the liquid. Place the lid on the cup to keep rain and critters from getting in, and place the trap in the holder. Adjust the hose clamp so that the trap fits in snugly but the trap holes are not covered up. Empty and re-bait the trap every week. Do not pour out the old bait on the ground near the trap, as this will draw flies away from it.

An effective commercial trap and bait is now available from Scentry. The trap is reusable and the bait lasts 4-6weeks. Cost for both is about $15 plus shipping, it is available from Great Lakes IPM Company (http://www.greatlakesipm.com/).

Other IPM Web Pages
Michigan State University
Penn State University
University of New Hampshire

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME 04259          Orono, ME 04473
207.933.2100                           1.800.287.0279

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

Town Spotted Wing  Drosophila weekly trap catch 7/6/17 Spotted Wing  Drosophila weekly trap catch 7/12/17
Wells 19
Sanford 0 4
Limington 4 2
Limerick 1 3
Cape Elizabeth 19 21
Buxton 12 6
New Gloucester 3 30
Bowdoinham 2 10
Dresden 0 0
Freeport 2 0
Poland Spring 1 2
Mechanic Falls 14 5
Monmouth 2 4
Wales 110
Farmington 0 3
Fayette 6 3

Sweet Corn IPM Newsletter No. 4 – July 14, 2017

July 14th, 2017 12:26 PM

Sweet CornSweet Corn IPM Newsletter No. 4 – July 14, 2017
Click on photos to enlarge.

Highmoor Farm Field Day
Wednesday, July 26, 2017
Save the date!

FALL ARMYWORM ACTIVE IN CORN FIELDS

Corn Earworm Spreading Throughout State

SITUATION
More fields are coming into silk this week and growth is looking good overall. Unfortunately, corn earworm numbers are increasing and fall armyworm has made its first appearance, threatening silking fields. Remember that applying sprays at the early tassel stage can provide good control of European corn borer and fall armyworm as they move from the whorl or tassel to the ears.

European corn borer:  Moth captures continue to be scattered and relatively low, but larval feeding activity was found in nearly all the fields we scouted. More fields were over the recommended spray thresholds with 15% of pre-tassel plants showing injury. Fields in Biddeford, Cape Elizabeth, Dayton, Nobleboro, Poland Spring, Sabattus and Wells were over threshold for pre-tassel corn so sprays were recommended. In silking corn, sprays may also be based on the number of moths caught in pheromone traps to prevent larvae from infesting the ears, but no fields were over the 5-moth threshold this week.

European Corn Borer Larvae on Pre-tassel Stage Corn

European Corn Borer Larvae on Pre-tassel Stage Corn, photo by David Handley

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Corn earworm: Moths have been more widely distributed and in higher numbers this week, but not all locations had captures or were over threshold for silking corn. Growers with early corn should be on the alert to protect any silking fields if moths are found in the area. A 6-day spray interval for corn earworm was recommended for silking fields in North Berwick and Wales this week. A 5-day spray interval was recommended for silking fields in Cape Elizabeth and Nobleboro. When no silking corn is available, corn earworm larvae may chew large, ragged holes in the leaves, similar to fall armyworm. This should be counted in field scouting for European corn borer and fall armyworm.

Fall armyworm:  The first confirmed fall armyworm moths were captured in our pheromone traps this week, and feeding damage was found in several fields. When feeding damage is found in a field, it is counted and combined with any European corn borer damage found. If the total injury exceeds 15% in corn at pre-tassel or beyond, a spray is recommended. Once the corn has reached the silking stage, sprays may be based on captures of moths in pheromone traps. This prevents larvae from getting into the silk channel and damaging ears without leaving visible injury for field scouting. If three or more moths are caught in a week in silking fields, a spray is recommended, unless the field is currently under a spray interval for corn earworm. Sprays for corn earworm should provide control of fall armyworm.

Male Fall Armyworm Moth

Male Fall Armyworm Moth, photo by David Handley

Male and Female Spotted Wing Drosophila Flies

Male (left) and Female (right) Spotted Wing Drosophila, photo by Griffin Dill. Actual size: 2-3 mm.

Spotted wing drosophila:  Flies have been in several Maine berry fields over the past week. Growers with ripening blueberries or raspberries should be on the alert for flies or larvae in the fruit. For details, visit our Spotted Wing Drosophila blog.

Squash vine borer moths were caught in pheromone traps in Wells, Biddeford, Cape Elizabeth, Nobleboro, Farmington, Oxford and New Gloucester this week. The Biddeford, Cape Elizabeth, New Gloucester and Oxford sites were above the 5 moths per week spray threshold, and a spray was recommended. This pest is active in much of the state. Growers with squash and pumpkins should be on the lookout for vine borer symptoms and protect squash plants if moths or damage are seen.

Highmoor Farm EntranceHOLD THE DATES:

Fruit and Vegetable Growers Field Day at Highmoor Farm: Wednesday July 26, 2017 from 8:30 a.m. to 3:00 p.m. Visit the Highmoor Farm website for more information. Please register by July 17! Call 207.933.2100 for additional registration information.

New England Vegetable & Fruit Conference is scheduled for December 12-14, 2017 in Manchester, NH.  Please visit the website, https://newenglandvfc.org/. Details and registration information coming soon.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      Pest Management Office
P.O. Box 179                            491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

Sweet Corn IPM Weekly Scouting Summary

Location CEW
Moths
ECB
Moths
FAW
Moths
%Feeding
Damage
Recommendations / Comments
Auburn 0 2 0 6% No spray recommended
Biddeford 0 0 2 23% One spray recommended for ECB
Bowdoinham 1 1 0 11% No spray recommended
Cape Elizabeth I 2 2 0 10% No spray recommended (no silking corn)
Cape Elizabeth II 6 0 2 23% 5-day spray interval recommended on all silking corn
Dayton I 1 0 0 22% One spray recommended for ECB
Dayton II 1 0 0 1% No spray recommended
Farmington 0 1 0 3% No spray recommended
Lewiston 0 0 6 0% One spray recommended for FAW on all silking corn
New Gloucester 0 0 0 3% No spray recommended
Nobleboro 5 2 6 27% 5-day spray interval recommended on all silking corn
North Berwick 3 0 0 5% 6-day spray interval recommended on all silking corn
Oxford 1 0 2 1% No spray recommended
Poland Spring 1 0 0 52% One spray recommended for ECB +FAW
Sabattus 1 0 0 32% One spray recommended for ECB
Wales 3 0 0 0% 6-day spray interval recommended on all silking corn
Wayne 1 0 0 10% No spray recommended
Wells I 0 0 0 21% One spray recommended for ECB on pre-tassel corn
Wells II 1 1 0 0% No spray recommended

CEW: Corn earworm (Only fresh silking corn should be sprayed for this insect.)
ECB: European corn borer
FAW: Fall armyworm

Corn Earworm Spray Thresholds for Pheromone Traps

Moths caught per week Moths caught per night Spray interval
0.0 to 1.4 0.0 to 0.2 No spray
1.5 to 3.5 0.3 to 0.5 Spray every 6 days
3.6 to 7.0 0.6 to 1.0 Spray every 5 days
7.1 to 91 1.1 to 13.0 Spray every 4 days
More than 91 More than 13 Spray every 3 days

Thresholds apply only to corn with exposed fresh silk. Lengthen spray intervals by one day if maximum daily temperature is less than 80°F.

European Corn Borer Thresholds
Whorl stage: 30% or more of plants scouted show injury.
Pre-tassel-silk: 15% or more of plants scouted show injury.
Silk: 5 or more moths caught in pheromone traps in one week.

IPM Web Pages:

UMaine Cooperative Extension IPM
Penn State Sweet Corn IPM
UMass Extension IPM Programs

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.