Archive for the ‘News’ Category

Spotted Wing Drosophila Alert: September 25, 2018

Tuesday, September 25th, 2018

SPOTTED WING DROSOPHILA ALERT: SEPTEMBER 25, 2018

Click on photos to enlarge.

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

Insects in Spotted Wing Drosophila Trap

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

Spotted Wing Drosophila Emerging from Fall Raspberries

SWD Emerging from Fall Raspberries, photo by James Dill

We regret that we have not been able to keep up regular weekly maintenance of all of our spotted wing drosophila (SWD) traps over the past few weeks, due to a shortage of help and conflicting schedules. We hope to keep the traps up for one more week, as frost is now bringing an end to the season for most parts of the state. In general, drosophila captures have been high enough to warrant regular sprays on all berry crops that are still being harvested, e.g. fall raspberries and day-neutral strawberries. While populations have been variable from site to site, ranging from the tens to the thousands, they have been high enough to result in rapid infestation of fruit if left untreated. (See table below.) A 5 to 7-day spray schedule on all ripening fruit should be adequate for most plantings. Make sure your sprayer is providing good coverage of the plant surface, especially in the lower part of the canopy, and try to keep any overripe or rotten fruit out of the field. Weather predictions suggest that conditions will continue to be good for SWD to infesting any ripening fruit, until either the fruit is gone, or we have experienced several hard frosts.

For more information on identifying spotted wing drosophila and updates on populations around the state, visit our SWD blog.

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

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                         UMaine Extension Diagnostic Research Lab
P.O. Box 179                               Pest Management Unit
52 U.S. Route 202                     17 Godfrey Drive
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 8/17/18 Spotted Wing  Drosophila weekly trap catch 8/24/18 Spotted Wing  Drosophila weekly trap catch 8/31/18 Spotted Wing  Drosophila weekly trap catch 9/7/18
Wells 5 12 48 114
Sanford 7
Limington 23 180 1600
Limerick 1 108 1680
Buxton 58
Bowdoinham 152 15 74 68
Cape Elizabeth 1441 353 312 197
Dresden 10 440
Freeport 7 173
Poland Spring 7 10 190 325
Mechanic Falls 2 13 66
Monmouth 74 469 1336 861
Readfield 51 140
Farmington 3 154 296
Fayette 0
Wales 4616 123 1512 328
Wayne 1 8 32

 

 

Sweet Corn IPM Newsletter No. 11 – September 6, 2018

Friday, September 7th, 2018

Sweet CornSweet Corn IPM Newsletter No. 11 – September 6, 2018
Click on photos to enlarge.

Last Issue for 2018!

MAJOR CORN EARWORM FLIGHT THREATENS LATE CORN

Any Late Silking Fields Remaining Require Tight Spray Interval

This will be the final issue of the Sweet Corn IPM Newsletter for the 2018 season. I would like to thank all of the growers who participated in the program this year, and our team of IPM scouts, including Lindsey Ridlon, Althea Hicks, Megan Knowles and Sean McAuley. Have questions, comments or suggestions about the program? Please call or email us.

SITUATION
Many farms will be finishing up corn harvest this week or next, as more hot, humid weather has hastened corn maturity and shortened the harvest season. Recent weather fronts from the west and south have brought a major flight of corn earworm and, to a lesser extent, fall armyworm into the state, most notably in southern and coastal sites. As a result, any late silking corn remaining will need to be protected regularly and often until the silks are completely dry.

European corn borer:  Although we started removing borer traps from fields last week, farms with traps remaining showed very little activity. Single moths were caught in traps in North Berwick, Wells and Sabattus. No sites were over the 15% spray threshold for larval feeding damage. Here’s another reminder to plow down your corn stalks after harvest. Plowing down the stalks destroys overwintering sites for European corn borer.

Corn Field Plowed Down

Corn Field Plowed Down, photo by David Handley

Oats Cover Crop

Oats Cover Crop, photo by David Handley

Corn earworm:  This week saw a significant jump in the number of moths found in our traps, indicating a severe threat to any silking corn remaining. Southern and coastal sites are being hardest hit, with some traps capturing over 100 moths. A 6-day spray interval for silking corn was recommended for Lewiston and Palmyra. A 5-day spray interval was recommended for Levant. A 4-day spray interval was recommended for silking fields in Charleston, Corinth, Dayton, Monmouth, New Gloucester, Nobleboro, Oxford, Poland Spring, Sabattus, Wayne and Wells. A 3-day spray interval was recommended for North Berwick, Biddeford and Cape Elizabeth.

Corn Earworm Feeding on Corn

Corn Earworm Feeding on Corn, photo by David Handley

Fall Armyworm Eggs on Corn

Fall Armyworm Eggs on Corn, photo by David Handley

Fall armyworm:  Armyworm moth numbers were higher at nearly all locations this week, similar to corn earworm. Fields in Biddeford, Cape Elizabeth, Dayton, Levant, Lewiston, Monmouth, New Gloucester, Nobleboro, North Berwick, Oxford, Poland Spring, Wayne and Wells were all over the three moths per week spray threshold for silking corn.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                 UMaine Extension Diagnostic Research Lab
P.O. Box 179                        Pest Management Unit
52 U.S. Route 202              17 Godfrey Drive
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
Recommendations / Comments
Biddeford 149 0 26 3-day spray interval recommended on all silking corn
Bowdoinham 1 2 No spray recommended
Cape Elizabeth I 113 0 23 3-day spray interval recommended on all silking corn
Cape Elizabeth II 500+ 121 3-day spray interval recommended on all silking corn
Charleston 15 0 0 4-day spray interval recommended on all silking corn
Corinth 13 0 0 4-day spray interval recommended on all silking corn
Dayton 73 0 19 4-day spray interval recommended on all silking corn
Levant 5 0 4 5-day spray interval recommended on all silking corn
Lewiston 2 0 8 6-day spray interval recommended on all silking corn
Monmouth 15 10 4-day spray interval recommended on all silking corn
New Gloucester 75 41 4-day spray interval recommended on all silking corn
Nobleboro 11 4 4-day spray interval recommended on all silking corn
North Berwick 112 1 3-day spray interval recommended on all silking corn
Oxford 8 96 4-day spray interval recommended on all silking corn
Palmyra 2 1 0 6-day spray interval recommended on all silking corn
Poland Spring 71 6 4-day spray interval recommended on all silking corn
Sabattus 11 1 1 4-day spray interval recommended on all silking corn
Wayne 36 13 4-day spray interval recommended on all silking corn
Wells I 11 0 1 4-day spray interval recommended on all silking corn
Wells II 64 0 38 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 Integrated Pest Management
UMass Amherst Integrated Pest Management

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. 10 – August 31, 2018

Friday, August 31st, 2018

Sweet CornSweet Corn IPM Newsletter No. 10 – August 31, 2018
Click on photos to enlarge.

CORN EARWORM, FALL ARMYWORM COUNTS LOWER

Most Silking Fields Still Require Protection

SITUATION
More hot, humid weather continues to push corn development ahead.  Most remaining fields are silking or ready to harvest as the holiday weekend approaches. Insect pressure was more variable this week, with moth counts generally down, but still high enough to warrant protection in nearly all silking fields. Growers continue to report problems with worms getting through their spray programs.

Corn Field Plowed Down

Corn Field Plowed Down, photo by David Handley

European corn borer:  Moth activity continues to decline this week. Moths were over the spray threshold for silking corn only in Sabattus, however this field was also on a spray interval for corn earworm. Feeding damage was very light, with no sites over the 15% spray threshold for pre-tassel to silking corn. Remember to plow down your corn stalks after harvest. Plowing down the stalks destroys overwintering sites for European corn borer.

Corn earworm:  Moth counts were down in most locations this week, but most sites still require a regular spray interval for silking corn. A 6-day spray interval for silking corn was recommended for Dayton, one Lewiston site, and one Wells site. A 5-day spray interval was recommended for Biddeford, Levant, Nobleboro, North Berwick, Wayne and one Wells site. A 4-day spray interval was recommended for silking fields in Cape Elizabeth, Monmouth, New Gloucester, Poland Spring, and Sabattus.

Fall Army Worm on Pre-tassel Corn Plant

Fall Army Worm on Pre-tassel Corn, photo by David Handley

Fall armyworm:  Moth counts were lower in most locations this week, although many sites were still over the spray threshold for silking corn. Fields in Biddeford, Cape Elizabeth, Monmouth, New Gloucester, North Berwick, Oxford and Wayne were all over the three moths per week spray threshold for silking corn. However, with the exception of the Oxford site, all of them were already following a recommended spray interval for corn earworm. Some growers who have reported problems with getting good control of both fall armyworm and corn earworm with their typical insecticide (usually a pyrethroid, class 3A) have been trying products with different active ingredients, and finding improved control.  Hot, sunny weather can significantly shorten the residual life of some pesticides, including pyrethroid types.  Growers should consider shortening the spray application interval or rotating to a different chemical class if corn is infested despite control efforts.

There’s still time for cover crops!
Plowing down corn stalks and stubble is an important means of managing European corn borer by destroying their over wintering sites. However, late plowing can leave soil exposed and prone to erosion during the winter and spring. Planting winter rye is a good alternative for many fields. Winter rye can often be planted well into September and still produce enough of a cover to prevent erosion. This grass will survive the winter and put on more growth in the early spring. It should be killed by plowing, mowing or herbicide before it goes to seed.  Bear in mind that having rye on the field may delay planting in the spring, as you must wait for conditions to be warm and dry enough to plow it in.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                  UMaine Extension Diagnostic
P.O. Box 179                         Research Lab, Pest Mgmt. Unit
52 U.S. Route 202               17 Godfrey Drive
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
Biddeford 7 0 7 4% 5-day spray interval recommended on all silking corn
Bowdoinham 0 0 0 0% No spray recommended
Cape Elizabeth I 19 0 12 4-day spray interval recommended on all silking corn
Cape Elizabeth II 26 2 4 4-day spray interval recommended on all silking corn
Charleston 1 0 0 No spray recommended
Corinth 1 0 1 No spray recommended
Dayton 2 0 1 6-day spray interval recommended on all silking corn
Farmington 1 0 0 No spray recommended
Levant 6 1 1 5-day spray interval recommended on all silking corn
Lewiston I 3 0 0 6-day spray interval recommended on all silking corn
Lewiston II 1 0 0 No spray recommended
Monmouth 13 7 4-day spray interval recommended on all silking corn
New Gloucester 16 0 5 4-day spray interval recommended on all silking corn
Nobleboro 4 0 1 5-day spray interval recommended on all silking corn
North Berwick 5 0 6 0% 5-day spray interval recommended on all silking corn
Oxford 0 0 17 20% Spray recommended for FAW
Palmyra 0 0 0 No spray recommended
Poland Spring 37 0 1 4-day spray interval recommended on all silking corn
Sabattus 9 9 0 4-day spray interval recommended on all silking corn
Wayne 6 0 3 5-day spray interval recommended on all silking corn
Wells I 2 0 0 6-day spray interval recommended on all silking corn
Wells II 4 1 1 5-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 Integrated Pest Management
UMass Amherst Integrated Pest Management

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. 9 – August 24, 2018

Monday, August 27th, 2018

Sweet CornSweet Corn IPM Newsletter No. 9 – August 24, 2018
Click on photos to enlarge.

CORN EARWORM PRESSURE REMAINS HIGH

All Late Silking Corn Requires Protection

SITUATION
Weather has continued to be good for both corn growth and pest populations.  More hot, humid weather predicted for the next several days will likely keep pest pressure at a high level; so, growers with fresh silking corn should remain vigilant and keep the silks protected until they have dried.

European corn borer:  With the exception of fields in Cape Elizabeth and Sabattus, moth activity was low this week. The five moths per week threshold was exceeded at one Cape Elizabeth site and Sabattus. However, both of these sites were also under a spray interval for corn earworm, which should also protect against corn borer. Feeding damage was very light, with no sites over the 15% spray threshold for pre-tassel to silking corn.

Corn earworm:  Moths were widespread and in higher numbers in some locations this week, so sprays were recommended for nearly all silking fields. A 6-day spray interval for all silking corn was recommended for Charleston, one Lewiston site, and Sabattus. A 5-day spray interval was recommended for Bowdoinham, Dayton, Levant, Monmouth, Palmyra, Wayne and one Wells site. A 4-day spray interval was recommended for silking fields in Biddeford, Cape Elizabeth, Corinth, Dayton, one Lewiston site, North Berwick, Nobleboro, Oxford, Poland Spring, and one Wells site.

Corn Earworm Moth

Corn Earworm Moth, photo by David Handley

Male Fall Armyworm Moth

Male Fall Armyworm Moth, photo by David Handley

Fall armyworm:  Although we did not catch moths at all locations, counts exceeded the spray threshold for silking corn where we did catch them with only one exception. Fields in Biddeford, Cape Elizabeth, Monmouth, Oxford, Poland Spring, Wayne and Wells were all over the three moths per week spray threshold for silking corn; but all of these sites were also on a recommended spray interval for corn earworm. On younger corn, larval feeding damage was over the 15% control threshold in Cape Elizabeth, Dayton, North Berwick and Oxford.

Bird Damage on Corn

Bird Damage on Corn, photo by David Handley

When Should You Stop Spraying?
When a silking corn field is under a recommended spray interval for corn earworm, we usually recommend that spraying be stopped once the silks have become thoroughly dried and brown. At this stage, corn earworm moths are unlikely to lay eggs on it. However, if earworm pressure is very high (e.g. 91+ moths per week) and/or fall armyworm moths are over threshold (3 or more moths per week), then spraying should probably continue until either the moth counts drop or you reach the required days before harvest (dh) for the product being used.

Birds, etc.: Flocking species of blackbirds are starting to cause damage in cornfields around the state. They are especially attracted to fields where corn has been allowed to get over-mature. Deer, skunks and raccoons have also been troublesome this year. For information on wildlife problems and management options, you may call the USDA Animal and Plant Health Inspection Service (APHIS) office in Augusta at 1.866.487.3297.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      UMaine Extension Diagnostic Research Lab
P.O. Box 179                             Pest Management Unit
52 U.S. Route 202                   17 Godfrey Drive
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
Biddeford 12 0 7 3% 4-day spray interval recommended on all silking corn
Bowdoinham 4 0 0 0% 5-day spray interval recommended on all silking corn
Cape Elizabeth I 30 0 37% 4-day spray interval recommended on all silking corn
Cape Elizabeth II 67 29 3 15% 4-day spray interval recommended on all silking corn
Charleston 3 0 0 6-day spray interval recommended on all silking corn
Corinth 12 1 1 4-day spray interval recommended on all silking corn
Dayton 7 0 0 15% 5-day spray interval recommended on all silking corn
Farmington 1 0 0 0% No spray recommended
Levant 4 0 0 5-day spray interval recommended on all silking corn
Lewiston I 15 0 0 4-day spray interval recommended on all silking corn
Lewiston II 2 0 0 6-day spray interval recommended on all silking corn
Monmouth 4 8 4% 5-day spray interval recommended on all silking corn
Nobleboro 11 0 0 4-day spray interval recommended on all silking corn
North Berwick 23 0 0 16% 4-day spray interval recommended on all silking corn
Oxford 13 0 8 20% 4-day spray interval recommended on all silking corn
Palmyra 5 3 0 5-day spray interval recommended on all silking corn
Poland Spring 31 0 4 0% 4-day spray interval recommended on all silking corn
Sabattus 2 5 0 6-day spray interval recommended on all silking corn
Wayne 6 0 4 8% 5-day spray interval recommended on all silking corn
Wells I 7 0 0 5-day spray interval recommended on all silking corn
Wells II 23 2 7 4% 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 Integrated Pest Management
UMass Amherst Integrated Pest Management

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 17, 2018

Monday, August 20th, 2018

SPOTTED WING DROSOPHILA ALERT: AUGUST 17, 2018

Click on photo to enlarge.

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

Captures of spotted wing drosophila (SWD) fruit flies in vinegar/yeast traps in raspberry and highbush blueberry plantings increased significantly at some locations this week, and is above threshold levels at most sites. Our highest counts of the season were found in raspberry plantings in Wales and Cape Elizabeth, with numbers now reaching into the thousands. (See table below.) Weather predictions suggest that conditions will continue to be good for SWD to continue increasing in fall raspberries, late blueberries, elderberries and fall strawberries. Growers with these crops should be putting on regular protective sprays if more than 4 flies have been captured in traps in a week. At this point a 5 to 7-day spray schedule should be adequate for most plantings. Make sure your sprayer is providing good coverage of the plant surface, especially in the lower part of the canopy.

Spotted Wing Drosophila Larvae in Elderberries

Spotted Wing Drosophila Larvae in Elderberries, photo by David Handley

For more information on identifying spotted wing drosophila and updates on populations around the state, visit our SWD blog.

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

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      UMaine Extension Diagnostic Research Lab
P.O. Box 179                             Pest Management Unit
52 US Route 202                     17 Godfrey Drive
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 8/3/18 Spotted Wing  Drosophila weekly trap catch 8/10/18 Spotted Wing  Drosophila weekly trap catch 8/17/18
Wells 0 0 5
Sanford 0 5 7
Limington 12 Trap down 23
Limerick 0 7 1
Buxton 0 11 58
Bowdoinham 2 34 152
Cape Elizabeth 1 18 1441
Dresden 5 49 10
Freeport 0 2 7
Poland Spring 0 2 7
Mechanic Falls 0 2 2
Monmouth 2 20 74
Readfield 12 17 51
Wales 2 216 4616
Farmington 1 0 3
Fayette 0 1 0
Wayne 0 0 1

 

 

Sweet Corn IPM Newsletter No. 8 – August 17, 2018

Monday, August 20th, 2018

Sweet CornSweet Corn IPM Newsletter No. 8 – August 17, 2018
Click on photos to enlarge.

FALL ARMYWORM, CORN EARWORM PRESSURE HIGH

Growers Report Difficulty Controlling Fall Armyworm

SITUATION
Warm weather continued to push corn development this week. Late-planted fields are mostly silking, and will be ready for the post-Labor Day market. We have had several cases of growers finding worm-infested ears in corn that either has been sprayed, or had not yet had a spray recommendation based on pheromone trap captures and field scouting. The damage appears to be from fall armyworm. We may have a type that is not well-matched to the pheromone bait we are using, and may have more tolerance to the pesticides that are typically being used.

European corn borer:  Moth activity increased at some sites this week, threatening silking corn in those fields. The five moths per week threshold was exceeded in Biddeford, one Dayton site, one Lewiston site, and Sabattus. However, all of these sites, except for Sabattus, were also under a spray interval for corn earworm, which should also protect against corn borer. Feeding damage was very light, with no sites over the 15% spray threshold for pre-tassel to silking corn.

Corn Earworm

Corn Earworm, photo by David Handley

Corn earworm:  Moths caught in traps were generally more widespread and in higher numbers this week, and sprays were recommended for nearly all silking fields. A 6-day spray interval for all silking corn was recommended for Corinth, one Lewiston site, Oxford, Palmyra and one site in Wells. A 5-day spray interval was recommended for Biddeford, Levant and New Gloucester. A 4-day spray interval was recommended for silking fields in Cape Elizabeth, Charleston, Dayton, one Lewiston site, North Berwick, Nobleboro, Wayne and one Wells site.

Fall Armyworm on Corn Leaf

Fall Armyworm on Corn Leaf, photo by David Handley

Fall armyworm:  Moth captures continue to be sporadic around the state, but are generally increasing and more widespread. Our fields in Biddeford, Cape Elizabeth, Corinth, Dayton, New Gloucester, Nobleboro, Oxford, Poland Spring and Wells were all over the three moths per week spray threshold for silking corn; but all of the sites were already on a recommended spray interval for corn earworm, with the exception of Poland Spring. With several farms now reporting infested ears at sites where few, if any moths were caught, we are recommending that growers protect any tassel-silking corn that has not yet been sprayed. It may be that the pheromone being used in our traps is not working well with the moths that have come into the state this year. As we reported last week, fall armyworm has been the most challenging species to trap in the past, and in some years the traps have not adequately predicted the damage we found to the ears. Growers are also reporting some infestation regardless of spraying, suggesting that the materials being used in the sprays are not performing well. We recommend that if you have seen problems with insecticide efficacy, you try changing the chemistry of the products you are using. For example, if you have using only synthetic pyrethroids (Warrior®, Bifenthrin®, group 3A), you should try a product in another chemical group, such as Coragen® or Belt SC® (Group 28). Evening sprays may also be more effective as the larvae tend to be more active and exposed at night.

On younger corn, fall armyworm damage was over the 15% control threshold in Biddeford and New Gloucester, although most sites had larvae feeding.

Sincerely,

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      UMaine Extension Diagnostic Research Lab
P.O. Box 179                             Pest Management Unit
52 U.S. Route 202                   17 Godfrey Drive
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
Biddeford 6 6 22 28% 5-day spray interval recommended on all silking corn
Bowdoinham 1 0 0 2% No spray recommended
Cape Elizabeth 9 2 6 3% 4-day spray interval recommended on all silking corn
Charleston 8 0 0 4-day spray interval recommended on all silking corn
Corinth 2 0 8 0% 6-day spray interval recommended on all silking corn
Dayton I 32 6 5 2% 4-day spray interval recommended on all silking corn
Dayton II 15 0 0 8% 4-day spray interval recommended on all silking corn
Farmington 0 3 0 0% No spray recommended
Levant 5 0 2 1% 5-day spray interval recommended on all silking corn
Lewiston I 22 0 2 4-day spray interval recommended on all silking corn
Lewiston II 2 5 0 6-day spray interval recommended on all silking corn
New Gloucester 7 1 9 18% 5-day spray interval recommended on all silking corn
North Berwick 38 0 0 3% 4-day spray interval recommended on all silking corn
Nobleboro 23 2 6 9% 4-day spray interval recommended on all silking corn
Oxford 2 0 6 5% 6-day spray interval recommended on all silking corn
Palmyra 2 2 0 0% 6-day spray interval recommended on all silking corn
Poland Spring 0 0 3 11% One spray for FAW on all silking corn
Sabattus 1 19 0 One spray for ECB on all silking corn
Wayne 9 0 0 4-day spray interval recommended on all silking corn
Wells I 3 0 0 6% 6-day spray interval recommended on all silking corn
Wells II 32 3 5 10% 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 Integrated Pest Management
UMass Amherst Integrated Pest Management

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 10, 2018

Friday, August 10th, 2018

SPOTTED WING DROSOPHILA ALERT: AUGUST 10, 2018

Click on photo to enlarge.

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

Captures of spotted wing drosophila (SWD) fruit flies in vinegar/yeast traps in raspberry and highbush blueberry plantings are now increasing in most locations, and at most sites counts rose above threshold levels, including one site with over 200 flies caught. (See table below.) The wet weather predicted for next week may further encourage SWD infestations, as these insects like moisture, and the rain will also lead to more rotten fruit in the field. Most summer-bearing raspberry fields are through or nearly through harvest, but fall fruiting raspberries and blackberries are now ripening and are very susceptible to infestation.  Later ripening blueberries and elderberries are also good hosts for SWD at this time. Growers with these crops should be putting on protective sprays. Pay close attention to product pre-harvest intervals and limits on the number of applications allowed for each product, to develop a management strategy that will be most effective for your situation.

Spotted Wing Drosophila Damage in Elderberry Plant

Spotted Wing Drosophila Damage in Elderberry Plant, photo by David Handley

For more information on identifying spotted wing drosophila and updates on populations around the state, visit our SWD blog.

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 7/27/18
Spotted Wing  Drosophila weekly
trap catch 8/3/18
Spotted Wing  Drosophila weekly
trap catch 8/10/18
Wells 0 0
Sanford 3 0 5
Limington 1 12 Trap down
Limerick 0 0 7
Buxton 5 0 11
Bowdoinham 1 2 34
Cape Elizabeth 1 18
Dresden 2 5 49
Freeport 0 0 2
Poland Spring 0 0 2
Mechanic Falls 0 0 2
Monmouth 0 2 20
Readfield 1 12 17
Wales 2 216
Farmington 1 0
Fayette 0 0 1
Wayne 0 0

 

 

 

Sweet Corn IPM Newsletter No. 7 – August 10, 2018

Friday, August 10th, 2018

Sweet CornSweet Corn IPM Newsletter No. 7 – August 10, 2018
Click on photos to enlarge.

CORN EARWORM, FALL ARMYWORM THREAT INCREASES

Silking Corn Fields Require Protection

SITUATION
All but the latest planted fields are now silk or beyond. Storm fronts approaching from the south and west have brought up more corn earworm and some fall armyworm to threaten fields with silking corn. Fall armyworm can be troubling at this time, as eggs laid on silking corn allow larvae to move into the ears undetected by field scouting.

European corn borer:  Moth activity declined in most locations this week, with the exception of a site in Sabattus. The five moths/week threshold was only exceeded in Sabattus and one Wells site. However, both of these sites were also under a spray interval for corn earworm, which should also protect against corn borer. Feeding damage was very light, with no sites over the 15% spray threshold for pre-tassel to silking corn.

Corn earworm:  Numbers of moths caught in traps increased at many sites this week, leading to sprays recommended for nearly all silking fields. A 6-day spray interval for all silking corn was recommended for one site in Wells. A 5-day spray interval was recommended for Bowdoinham, Charleston, one Lewiston site, Palmyra, Sabattus and Wayne. A 4-day spray interval was recommended for silking fields in Biddeford, Cape Elizabeth, Dayton, Levant, and one Wells site.

Corn Earworm Larvae

Corn Earworm Larvae, photo by David Handley

Fall Armyworm on Corn Silk

Fall Armyworm on Corn Silk, photo by David Handley

Fall armyworm:  We have started catching moths in our pheromone traps this week, but these have not yet been widespread. This species has historically been the most challenging to trap, and in some years the traps have performed poorly in terms of predicting the damage we find in the field and ears. This may be the situation this season as we have heard from a grower of ears being infested, despite no captures of moths in our traps. This is why we recommend growers consider applying an insecticide when the corn is in the late pre-tassel to tassel/early silk stage, especially if any moth activity or feeding damage has been observed in the field, because this is often when caterpillars are most exposed, as they move from one part of the plant to another. It is also the time when protection of the emerging silk is most critical to prevent infestation. Furthermore, fall armyworm larvae can be difficult to control despite regular sprays, as they tend to be more resistant to many of the insecticides used in corn than the other species we target. Remember, the larvae also tend to be more exposed at night, making evening sprays more effective. The addition of a spreader-sticker with the insecticide can also help to get the best coverage possible and extend the effective time of the application.

Corn leaf aphids: These insects often infest corn plants later in the season, especially in fields that have not recently been sprayed for other pests. Colonies of bluish-green aphid can cover tassels, stalks and husks. Their waste encourages the dark, slimy sooty mold fungus, which covers the surface of the husks. Sprays for corn earworm will usually control aphids.

Aphids on Corn Tassel

Aphids on Corn Tassel, photo by Kaytlin Woodman

Rust on Corn

Rust on Corn, photo by David Handley

Corn rust:  Rust is a fungus disease that causes reddish-brown pustules on corn leaves and husks, reducing the quality of the ears. A fungicide spray for rust would only be recommended if the infection were noticed in a field prior to tasseling. Later infections are unlikely to cause enough damage to the crop to justify control measures. Materials available to control corn rust include Quadris®, Bravo®, and Quilt®.

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
Biddeford 14 1 0 1% 4-day spray interval recommended on all silking corn
Bowdoinham 5 0 0 4% 5-day spray interval recommended on all silking corn
Cape Elizabeth 65 1 0 0% 4-day spray interval recommended on all silking corn
Charleston 6 0 0 0% 5-day spray interval recommended on all silking corn
Corinth 8 0 2 1% 4-day spray interval recommended on all silking corn
Dayton I 18 0 0 0% 4-day spray interval recommended on all silking corn
Dayton II 28 2 0 0% 4-day spray interval recommended on all silking corn
Farmington 0 2 3 One spray for FAW on all silking corn
Levant 14 0 0 1% 4-day spray interval recommended on all silking corn
Lewiston I 0 2 18 2% One spray for FAW on all silking corn
Lewiston II 4 2 0 5-day spray interval recommended on all silking corn
New Gloucester 1 0 0 1% No spray recommended
Oxford 1 0 5 1% One spray for FAW on all silking corn
Palmyra 6 3 0 0% 5-day spray interval recommended on all silking corn
Sabattus 7 47 5-day spray interval recommended on all silking corn
Wayne 7 2 5 10% 5-day spray interval recommended on all silking corn
Wells I 2 0 0 0% 6-day spray interval recommended on all silking corn
Wells II 50 7 0 6% 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 Integrated Pest Management
UMass Amherst Integrated Pest Management

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 6, 2018

Monday, August 6th, 2018

SPOTTED WING DROSOPHILA ALERT: AUGUST 6, 2018

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 Larvae in Blueberry

Spotted Wing Drosophila Larvae in Blueberry, photo by David Handley

Captures of spotted wing drosophila (SWD) fruit flies in vinegar/yeast traps in raspberry and highbush blueberry plantings remained low in most locations, although at two sites ((Limington, Readfield) counts rose above threshold levels. (See table below.) The recent warm, wet weather will encourage SWD infestations, however, as it may lead to more rotten fruit in the field and increase ambient moisture levels. Growers should try to keep rotten fruit out of the field as much as possible and encourage dry conditions by pruning out excess growth, especially near the base of the plantings. Growers who have been catching flies in their traps for more than one week and have ripening fruit should put on a protectant spray.

We expect spotted wing drosophila populations to increase significantly in the coming weeks as more ripe and rotten fruit becomes available for the flies. Protective sprays should be applied if more than four spotted wing drosophila flies are caught in a trap, flies are caught consistently for more than one week, or any larvae are noticed in the fruit. Look for fruit flies hovering around fruit and symptoms of premature fruit decay.

For more information on identifying spotted wing drosophila and updates on populations around the state, visit our SWD blog.

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 7/20/18 Spotted Wing  Drosophila weekly trap catch 7/27/18 Spotted Wing  Drosophila weekly trap catch 8/3/18
Wells 0
Sanford 13 3 0
Limington 1 1 12
Limerick 0 0 0
Buxton 3 5 0
Bowdoinham 1 1 2
Cape Elizabeth 1
Dresden 5 2 5
Freeport 0 0 0
Poland Spring 1 0 0
Mechanic Falls 0 0 0
Monmouth 3 0 2
Readfield 0 1 12
Wales 5 2
Farmington 8 1
Fayette 0 0 0
Wayne 0 0

 

 

 

Sweet Corn IPM Newsletter No. 6 – August 3, 2018

Monday, August 6th, 2018

Sweet CornSweet Corn IPM Newsletter No. 6 – August 3, 2018
Click on photos to enlarge.

CORN EARWORM THREATENS ALL SILKING CORN

Most Sites Now Have Significant Moth Populations in Silking Corn

SITUATION
As predicted, the warm weather from the south has brought an increase in insect activity, as we come into the peak of the sweet corn season. Growers should be monitoring their fields regularly and be prepared to protect silking corn from the threat of earworm and corn borer. Fall armyworm is likely to become more of a threat in the coming days.

European corn borer:  Activity in pheromone traps increased in most fields this week, although it has not yet led to a noticeable increase in feeding damage. This will likely follow soon however, as the eggs these moths are laying begin to hatch. When more than 5 moths are caught in a trap in a week, a spray is recommended for all silking corn to prevent larvae from entering the ears directly after hatching. Moths exceeded this threshold in Bowdoinham, Garland, Lewiston, New Gloucester, Oxford and Wells. However, all of these sites, except the one Wells field, were also under a spray interval for corn earworm, which should also protect against corn borer. Feeding damage in the field was very light, with no sites over the 15% spray threshold for pre-tassel to silking corn; but this is likely to increase soon.

European Corn Borer Larva

European Corn Borer Larva, photo by David Handley

Corn Earworm Feeding on Corn

Corn Earworm Feeding on Corn, photo by David Handley

Corn earworm:  Numbers of moths caught in traps increased significantly at nearly all sites monitored this week, leading to sprays recommended for corn in most silking fields. A 6-day spray interval for all silking corn was recommended for our sites in Bowdoinham, one Lewiston site, North Berwick, and Oxford. A 5-day spray interval was recommended for one Cape Elizabeth site, Dayton, Garland, one Lewiston site, Nobleboro, Poland, Sabattus and Wayne. A 4-day spray interval was recommended for silking fields in Biddeford, one Cape Elizabeth site, one Dayton site, Levant, New Gloucester, and one Wells site. At this point, it is likely corn earworm pressure will continue and growers should be prepared to protect all silking corn.

Fall armyworm:  No moths were caught in our pheromone traps this week, but we anticipate we will be seeing them soon because we are finding some larval feeding. None of the injury was over the 15% spray threshold.

Squash vine borer:  Moths were over the 5 moth per week threshold in Oxford. All other sites had either one or no moths this week.

Spotted wing drosophila:  Fly counts have been variable this week, with some locations seeing increases (Limington, Readfield) while most locations still had very few, if any flies. The recent heat and rain will improve conditions for spotted wing drosophila (SWD), because they likely increased the amount of rotten fruit in the field and the level of moisture. Both are conducive to fly presence and reproduction. Try keep the planting as free from rotten fruit as possible, remove excess vegetative growth, especially near the base of the plants, and apply a suitable insecticide when flies are observed or larvae are found in the fruit. For more information visit our SWD blog.

Male Spotted Wing Drosophila

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

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
Biddeford 8 1 0 0% 4-day spray interval recommended on all silking corn
Bowdoinham 2 16 0 0% 6-day spray interval recommended on all silking corn
Cape Elizabeth I 4 0 0 0% 5-day spray interval recommended on all silking corn
Cape Elizabeth II 24 1 0 4% 4-day spray interval recommended on all silking corn
Charleston 0 2 0 0% No spray recommended
Dayton I 4 0 0 0% 5-day spray interval recommended on all silking corn
Dayton II 8 3 0 2% 4-day spray interval recommended on all silking corn
Farmington 0 2 0 0% No spray recommended
Garland 4 5 0 5-day spray interval recommended on all silking corn
Levant 33 0 0 1% 4-day spray interval recommended on all silking corn
Lewiston I 2 5 0 0% 6-day spray interval recommended on all silking corn
Lewiston II 5 3 0 0% 5-day spray interval recommended on all silking corn
New Gloucester 12 5 0 0% 4-day spray interval recommended on all silking corn
Nobleboro 6 3 5-day spray interval recommended on all silking corn
No. Berwick 3 2 0 1% 6-day spray interval recommended on all silking corn
Oxford 2 15 0 0% 6-day spray interval recommended on all silking corn
Palmyra 0 3 0 0% No spray recommended
Poland 5 0 0 5-day spray interval recommended on all silking corn
Sabattus 6 2 0 5-day spray interval recommended on all silking corn
Wales 1 1 0 0% No spray recommended
Wayne 4 0 0 0% 5-day spray interval recommended on all silking corn
Wells I 0 28 0 1% One spray for ECB on all silking corn
Wells II 14 2 0 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 Integrated Pest Management
UMass Amherst Integrated Pest Management

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.