Vegetable IPM Reports

Hello vegetable IPM folks! 

This is the last report for 2024! The trap counts are for the last two weeks (9/30-10/11). Please take note of the upcoming Climate Resilience Workshops this month. A 2024 season summary is included after this week’s trapping report.

Introducing the new Hillsborough County Field Specialist!

Liza DeGenring (Liza.DeGenring@unh.edu) has joined UNH Extension’s Food & Agriculture Team and Hillsborough County as the new Field Specialist. Liza is a UNH alum, receiving her master’s and PhD degrees in Agricultural Science with a focus on plant pathology. Liza’s work has focused on evaluating alternative tools for plant disease management across a broad range of crop systems including tree fruit, vegetables, row crops, and greenhouse ornamentals. Liza will be working with Amber and Linda on the IPM Monitoring Program moving forward. We are lucky to have her on our Extension team!

 Upcoming events:

-Climate Resilience Workshops (register here)! October 18 and 23, 2024. In partnership with the NH County Conservation District and NH NRCS, UNH Extension is hosting two upcoming events showcasing NH farms that are implementing projects to address climate resilience issues of water availability and soil health. The events will focus on tours of the farms and their projects, including Q&As with topic experts and information about financial and technical resources available to farms through the presenting partners. These events are free and open to the public.

• October 18, 2024 from 9 a.m. – 11 a.m. at Clyde Farm, Farmington, NH – Farm Ponds and Water Sources: drought resistance, farm ponds, wells, and irrigation.
• October 23, 2024 from 4 p.m. – 6 p.m. at Wild Fern Farm, Kingston, NH – Soil Heath Practices: the science of soil health, mulching, reduced tillage, and working in small areas.

-New England Fruit and Vegetable Conference (register here!) December 17-19, 2024. The NEVF Conference includes more than 25 educational sessions over three days, covering major vegetable, berry and tree fruit crops as well as various special topics. A Farmer to Farmer meeting after each morning and afternoon session will bring speakers and farmers together for informal, in-depth discussion on certain issues. This conference is put together with close collaboration between growers and Extension from across the region. There is also an extensive Trade Show with over 120 exhibitors.

Funding opportunities for farmers through SARE

Farm Grant calls are out and due November 12^th, 2024.  For more information, see the Northeast SARE Farmer Grant Program page. Many Q&A sessions are available on October 8, 16, 22, 30. from 12 to 1 EST. You can register to attend here.

Please sign up for our text service! Text UNHIPM to 866-645-7010 to subscribe.

For any plant disease diagnostics, contact the UNH Extension Plant Diagnostic Lab to submit a sample.

Vegetable IPM Report, 9/30-10/11/24

Corn earworm decreased again compared to the last week of September (52) with numbers falling to 9 and then 0. Fall armyworm also decreased down to 48 (from 65 the week prior) and then to 20.

Table 1. Sweet corn pest weekly summary. CEW is in top two panels and FAW is below.

Squash vine borer numbers were zero, 9/30/24-10/4/24 and traps were removed.   

Spotted wing drosophila (SWD) numbers decreased and then increased again but with much lower numbers found in the control traps compared to previous weeks and months.

Table 3. Male SWD trap captures.

Brown marmorated stink bug adult counts almost doubled the first week of October and then dropped again the following week, with very few nymph catches (Table 4). Anna Wallingford recorded a podcast on BMSB that can be found here. You can also read through the transcript rather than listen if that is preferred. In NH, BMSB is more of a nuisance pest but can cause damage to agricultural crops, along with many of our native stink bugs, which we have seen in high numbers this season.

Table 4. BMSB trap captures.

*2024 Season Pest Trends*

European corn borer numbers in 2024 were lower than in 2023, by almost half. The wet fall and mild winter may have contributed to lower overwintering survival. In addition to lower pressure this year, we did not see a 2^nd generation in 2024 which is uncommon. The only location where we caught ECB consistently was in Sullivan County. I also observed ECB in sunflower and hemp crops.

2024 European corn borer. The left axis and columns (orange) represent the total numbers of ECB caught each week, and the right axis and line (blue) represent the average caught per week.

We saw a high spike in corn earworm numbers in late July 2024 (800 moths) due to many storms bringing moths up from the southern US. We were still capturing over 100 moths weekly in early September and saw another small spike in populations in September, like the small spike in late June when we began trapping. In 2023, CEW moth captures started increasing in August and we did not see a CEW peak until mid-September (600 moths), whereas we observed CEW increasing a month earlier in 2024.

2024 Corn earworm. The left axis and columns (orange) represent the total numbers of CEW caught each week, and the right axis and line (blue) represent the average caught per week. Of note: The average is higher at the beginning of the season because we had less traps deployed in the field.

Fall armyworm moths are not known to overwinter in New Hampshire, but we observed mature larvae feeding in June 2024. Field corn growers also reported seeing FAW caterpillars earlier than expected this year. We did not have traps out when Linda observed the caterpillars in mid-June, so it could have been from a flight that came in spring 2024 on storms, carrying both FAW and CEW. We will be deploying FAW and CEW traps sooner in 2024. Most of the feeding damage observed in sweet corn this year was from FAW larvae. FAW remained relatively high all season, with two peaks, one in late July, like with CEW, because of storms bringing moths north, and again in early September. FAW pressure was significantly higher in 2024 than in 2023, where total captures never surpassed 40 moths/week. FAW numbers also started increasing a month earlier in 2024 compared to 2023.

2024 Fall armyworm. The left axis and columns (orange) represent the total numbers of FAW caught each week, and the right axis and line (blue) represent the average caught per week.

Western bean cutworm is a newer pest to New England, moving east from the US corn belt. We observed one spike at the end of July and then the numbers dropped substantially. In 2023, we caught WBC around the same time of year, but we saw a slow decrease in adult moth captures compared to the drastic drop observed in 2024.

2024 Western bean cutworm. The left axis and columns (orange) represent the total numbers of WBC caught each week, and the right axis and line (blue) represent the average caught per week.

Squash vine borer numbers were high for a long period in 2024, and we observed a 2^nd generation for the first time since 2013. First generation larvae bore into cucurbit stems and the 2^nd generation bore into the fruit.

2024 Squash vine borer. The left axis and columns (orange) represent the total numbers SVB caught each week, and the right axis and line (blue) represent the average caught per week.

Brown marmorated stink bug numbers have increased over the past few weeks, which is expected at this time of year, though the total numbers are much higher than in 2023.

2024 Brown marmorated stink bug. The left axis and columns (orange) represent the total numbers BMSB caught each week (adults and nymphs combined), and the right axis and line (blue) represent the average caught per week.

Spotted wing drosophila were captured earlier than expected in 2024, which affected cherries and some strawberries. We usually expect SWD to arrive by early July (like in 2023), but we began catching SWD in mid-June this year. SWD numbers were higher in August 2023 compared to 2024.

2024 Spotted wing drosophila. This graph represents total SWD over time by crop. Dark blue = cherry, orange = strawberry, green = raspberry, blue = blueberry, purple = control (unmanaged/unsprayed habitats near small fruit).

Thank you to all the growers who participate in the program! Our annual surveys will be distributed in the coming weeks.

Contact: Amber Vinchesi-Vahl, UNH Extension State Specialist, Entomology and IPM, Amber.Vinchesi@unh.edu

This program is made possible thought funding provided by the New Hampshire Department of Agriculture, Markets & Food Integrated Pest Management Program. This work is also supported in part by the Integrated Pest Management Crop Protection and Pest Management Extension Implementation Plan from the USDA National Institute of Food and Agriculture. 

Hello vegetable IPM folks! 

I hope the harvest is going well for everyone! Our trapping season is wrapping up this week. This will be the last standard Vegetable IPM Report. The next and final report will include seasonal trends and patterns as a summary of the 2024 season. Take note of the upcoming Climate Resilience Workshops in October (listed under Upcoming Events below).

Fall armyworm and corn earworm numbers have decreased again compared to last week, and some locations have been removed since traps have been pulled and the corn season is ending. The results of our trapping efforts for sweet corn pests are recorded by town in Table 1 below. In some cases, there are multiple traps within a town.

Table 1. Sweet corn pest weekly summary, 9/23/2024-9/27/2024.

Cucurbit downy mildew has been reported in New Hampshire on cucumber and recently on pumpkin in New Jersey (see this alert from UMass). Please see our most recent blog post here. More information on CDM can be found in the NE Vegetable Management Guide. UMass also has more information on managing cucurbit downy mildew in a recent issue of their Veg Notes, which you can find here.

Squash vine borer numbers are the same as last week, almost zero, but the locations of captures have changed, and some traps have been removed. We are at the end of the 2nd generation (Table 2). We have not seen a second generation in New Hampshire since 2013. SVB’s 2nd generation affects winter squash and other late varieties. The larvae from the 2nd generation can bore into squash fruit, leaving them unmarketable and this can also lead to secondary rot. They can also survive in plant residue and become a bigger issue in the future, so sanitation is a key management tool to reduce next year’s population.  

Table 2. Squash vine borer weekly summary, 9/23/2024-9/27/2024.

 Spotted wing drosophila (SWD) numbers have decreased this week. We trap for SWD in Goffstown, Concord, Litchfield and Hollis, NH. Trap captures by crops can be found in Table 3 below. More information on monitoring for SWD can be found here.

Table 3. Male SWD trap captures, 9/23/24-9/27/24.

 Brown marmorated stink bug adult counts have decreased quite a bit from last week, with a small uptick in nymph catches (Table 4). Anna Wallingford recorded a podcast on BMSB that can be found here. You can also read through the transcript rather than listen if that is preferred. In NH, BMSB is more of a nuisance pest but can cause damage to agricultural crops, along with many of our native stink bugs, which we have seen in high numbers this season.

Table 4. BMSB trap captures, 9/23/24-9/27/24.

 Thank you to all the growers who participate in the program! Our annual surveys will be distributed in the coming weeks.

For any plant disease diagnostics, contact the UNH Extension Plant Diagnostic Lab to submit a sample.

Upcoming events:

-Climate Resilience Workshops (register here)! October 18 and 23, 2024. In partnership with the NH County Conservation District and NH NRCS, UNH Extension is hosting two upcoming events showcasing NH farms that are implementing projects to address the climate resilience issues of water availability and soil health. The events will focus on tours of the farms and their projects, including Q&As with topic experts and information about financial and technical resources available to farms through the presenting partners. These events are free and open to the public.

·         October 18, 2024 from 9 a.m. – 11 a.m. at Clyde Farm, Farmington, NH – Farm Ponds and Water Sources: drought resistance, farm ponds, wells, and irrigation.

·         October 23, 2024 from 4 p.m. – 6 p.m. at Wild Fern Farm, Kingston, NH – Soil Heath Practices: the science of soil health, mulching, reduced tillage, and working in small areas.

Funding opportunities for farmers through SARE

Farm Grant calls are out and due November 12th, 2024.  For more information, see the Northeast SARE Farmer Grant Program page. Many Q&A sessions are available on October 8, 16, 22, 30. from 12 to 1 EST. You can register to attend here.

Please sign up for our text service! Text UNHIPM to 866-645-7010 to subscribe.

Contact: Amber Vinchesi-Vahl, UNH Extension State Specialist, Entomology and IPM, Amber.Vinchesi@unh.edu

This program is made possible thought funding provided by the New Hampshire Department of Agriculture, Markets & Food Integrated Pest Management Program. This work is also supported in part by the Integrated Pest Management Crop Protection and Pest Management Extension Implementation Plan from the USDA National Institute of Food and Agriculture. 

Hello vegetable IPM folks!

I hope the harvest is going well for everyone!

European corn borer (ECB) numbers are almost zero and most of the traps are being pulled, though we caught 1 ECB in Sullivan County this week. We have also seen ECB infesting young sunflower stalks and hemp this year, so be aware that they can also be problematic for other crops too.

Fall armyworm numbers have more than doubled with certain locations seeing high numbers of moths. Most of the feeding damage we have observed this season is from FAW caterpillars. Larval feeding damage is characterized by large, ragged holes in leaves, and sawdust-like excrement. With silking corn, the trap threshold is 3+ moths per week. Adults lay eggs on corn foliage.

Corn earworm captures have doubled compared to last week. If you have silking corn, be sure to scout for CEW and prepare for management. Our trap threshold/spray schedule table is below and can be found in the fact sheet linked below as well, along with those for ECB and FAW. Thresholds apply only to corn in the fresh silk stage. If the maximum daily temperature is less than 80°F, you can lengthen the spray interval by one day.

Corn earworm spray thresholds for pheromone traps.

Western bean cutworm numbers were zero and traps have been pulled.

Field scouting should begin once moths are captured at your farm or in your area. Information on scouting for sweet corn pests and spray thresholds can be found here. The results of our trapping efforts for sweet corn pests are recorded by town in Table 1 below. In some cases, there are multiple traps within a town.

Table 1. Sweet corn pest weekly summary, 9/3/2024-9/9/2024.

Cucurbit downy mildew has been reported in New Hampshire on cucumber and recently on pumpkin in New Jersey (see this alert from UMass). Please see our most recent blog post here. More information on CDM can be found in the NE Vegetable Management Guide. UMass also has more information on managing cucurbit downy mildew in a recent issue of their Veg Notes, which you can find here.

Squash vine borer numbers are trending down, either from control measures or the end of the 2^nd generation (Table 2). We have not seen a second generation in New Hampshire since 2013. SVB’s 2^nd generation affects winter squash and other late varieties. The larvae from the 2nd generation can bore into squash fruit, leaving them unmarketable and this can also lead to secondary rot. It may be useful to move pheromone traps to winter squash plantings. Treatment with insecticides (targeted at fruit for 2^nd gen.) is warranted if trap counts rise above 5 moths/week. They can also survive in plant residue and become a bigger issue in the future.

Table 2. Squash vine borer weekly summary, 9/3/2024-9/9/2024.

Spotted wing drosophila (SWD) numbers have decreased a little but remain similar to last week. We trap for SWD in Goffstown, Concord, Litchfield and Hollis, NH. Trap captures by crops can be found in Table 3 below. If you have susceptible ripening fruit, I recommend monitoring and managing for SWD, especially with raspberries this time of year. More information on monitoring for SWD can be found here.

Table 3. Male SWD trap captures, 9/3/24-9/6/24.

Brown marmorated stink bug adult counts have almost tripled from last week (Table 4). Anna Wallingford recorded a podcast on BMSB that can be found here. You can also read through the transcript rather than listen if that is preferred. In NH, BMSB is more of a nuisance pest but can cause damage to agricultural crops, along with many of our native stink bugs, which we have seen in high numbers this season.

Table 4. BMSB trap captures, 9/3/24-9/6/24.

Check back each week as the season progresses to see the latest trapping data. Data for additional insect pests will be updated on a weekly basis. Thank you to all the growers who participate in the program! 

For any plant disease diagnostics, contact the UNH Extension Plant Diagnostic Lab to submit a sample.

 Misc. issues:

 -Late blight has been confirmed in Maine and Vermont. Protectant fungicides are a key tool for management. However, many strains of late blight are resistant to mefenoxam (Ridomil). Avoid overhead irrigation and immediately plow under old tomato fields after harvest. It is also helpful to eliminate cull piles and volunteer plants of both tomato and potato. See NE Veg Mgmt Guide for more information.

-Black cutworms have been found in a couple of locations. The larvae feed at night and hide in the soil during the day. Larger larvae can cut or girdle the stems of vegetable crops. Weedy and no-till fields are more susceptible to cutworm damage. Spot treatments on field edges or heavily infested areas may be helpful and will be most effective if applied at night while caterpillars are exposed. Fall plowing and conserving beneficial insects (like ground beetles) can be helpful for management as well.

-Bacterial wilt is transmitted by cucumber beetles. This disease causes foliage to turn a dull green and wilt during the day, recovering at night. As the disease progresses, leaves eventually turn yellow and brown at the margins and die back. Cucumber and muskmelons are more susceptible, along with younger plants. If you suspect bacterial wilt, you can cut the stem and if it oozes, it is probably bacterial wilt. You can also touch the cut ends of the stem together and if spider-web like threads appear between, that is another bacterial wilt indication. Crop rotation and row covers are effective strategies to control cucumber beetles. Timely and effective early chemical control is recommended in highly susceptible young plants when there is 1 beetle for every 2 plants. More information on products and cucumber beetle management can be found in the NE Veg Mgmt Guide.

Funding opportunities for farmers through SARE

Farm Grant calls are out and due November 12^th, 2024. For more information, see the Northeast SARE Farmer Grant Program page. Many Q&A sessions are available on October 8, 16, 22, 30. from 12 to 1 EST. You can register to attend here.

Please sign up for our text service! Text UNHIPM to 866-645-7010 to subscribe.

Contact: Amber Vinchesi-Vahl, UNH Extension State Specialist, Entomology and IPM, Amber.Vinchesi@unh.edu

This program is made possible thought funding provided by the New Hampshire Department of Agriculture, Markets & Food Integrated Pest Management Program. This work is also supported in part by the Integrated Pest Management Crop Protection and Pest Management Extension Implementation Plan from the USDA National Institute of Food and Agriculture.

Hello vegetable IPM folks! 

I hope the harvest is going well for everyone! Our trapping season is wrapping up this month and there will likely only be 1 or 2 more Veg IPM Reports this year.

European corn borer (ECB) numbers are zero and traps have been removed for the season.

Fall armyworm numbers have decreased, and some locations have been removed since traps have been pulled and the corn season is ending. Most of the feeding damage we have observed this season is from FAW caterpillars. Larval feeding damage is characterized by large, ragged holes in leaves, and sawdust-like excrement. With silking corn, the trap threshold is 3+ moths per week. Adults lay eggs on corn foliage.

Corn earworm captures have also decreased, with locations being removed due to corn season ending and traps removed. If you have silking corn, be sure to scout for CEW and prepare for management. Our trap threshold/spray schedule table is below and can be found in the fact sheet linked below as well, along with those for ECB and FAW. Thresholds apply only to corn in the fresh silk stage. If the maximum daily temperature is less than 80°F, you can lengthen the spray interval by one day.

Corn earworm spray thresholds for pheromone traps.

 Linda observed 6% fall armyworm feeding in Hudson this past week and aphids in Mason, NH. Field scouting should begin once moths are captured at your farm or in your area. Information on scouting for sweet corn pests and spray thresholds can be found here. The results of our trapping efforts for sweet corn pests are recorded by town in Table 1 below. In some cases, there are multiple traps within a town.

Table 1. Sweet corn pest weekly summary, 9/9/2024-9/13/2024.

Cucurbit downy mildew has been reported in New Hampshire on cucumber and recently on pumpkin in New Jersey (see this alert from UMass). Please see our most recent blog post here. More information on CDM can be found in the NE Vegetable Management Guide. UMass also has more information on managing cucurbit downy mildew in a recent issue of their Veg Notes, which you can find here.

Squash vine borer numbers continue to trend down, likely from the end of the 2nd generation (Table 2). We have not seen a second generation in New Hampshire since 2013. SVB’s 2nd generation affects winter squash and other late varieties. The larvae from the 2nd generation can bore into squash fruit, leaving them unmarketable and this can also lead to secondary rot. It may be useful to move pheromone traps to winter squash plantings. Treatment with insecticides (targeted at fruit for 2nd gen.) is warranted if trap counts rise above 5 moths/week. They can also survive in plant residue and become a bigger issue in the future.

Table 2. Squash vine borer weekly summary, 9/9/2024-9/13/2024.

Spotted wing drosophila (SWD) numbers have decreased in crops but increased in control traps. We trap for SWD in Goffstown, Concord, Litchfield and Hollis, NH. Trap captures by crops can be found in Table 3 below. If you have susceptible ripening fruit, I recommend monitoring and managing for SWD, especially with raspberries this time of year. More information on monitoring for SWD can be found here.

Table 3. Male SWD trap captures, 9/9/24-9/13/24.

Brown marmorated stink bug adult counts are similar to last week (Table 4). Anna Wallingford recorded a podcast on BMSB that can be found here. You can also read through the transcript rather than listen if that is preferred. In NH, BMSB is more of a nuisance pest but can cause damage to agricultural crops, along with many of our native stink bugs, which we have seen in high numbers this season.

Table 4. BMSB trap captures, 9/9/24-9/13/24.

 Check back each week as the season progresses to see the latest trapping data. Data for additional insect pests will be updated on a weekly basis. Thank you to all the growers who participate in the program! 

For any plant disease diagnostics, contact the UNH Extension Plant Diagnostic Lab to submit a sample.

 Misc. issues:

-Black cutworms have been found in a couple of locations. The larvae feed at night and hide in the soil during the day. Larger larvae can cut or girdle the stems of vegetable crops. Weedy and no-till fields are more susceptible to cutworm damage. Spot treatments on field edges or heavily infested areas may be helpful and will be most effective if applied at night while caterpillars are exposed. Fall plowing and conserving beneficial insects (like ground beetles) can be helpful for management as well. 

-Stink bug damage on tomatoes. Stink bugs can feed on tomatoes with their piercing-sucking mouthparts. The damage looks like pinpricks surrounded by a light discolored area. These feeding wounds can make fruit pithy or corky under the surface. Stink bugs can introduce yeasts when feeding, which can lead to fruit decay and encourage other pathogens to develop. Border treatments are usually effective for management. More information can be found in the NE Veg Mgmt Guide.

-Corn leaf aphids have been observed on and off this season, with the most recent observations last week. They first colonize whorl leaves and immature tassels. Corn leaf aphids can build to severe levels that interfere with pollen shed, stunt plants, and infest layers of the husk. The presence of aphids and honeydew on corn husks reduces their marketability. Varieties with purple or green tassels seem less susceptible to aphid build-up than those with yellow tassels. Ample rainfall or irrigation during the silk stage can reduce or eliminate aphid damage. Sweet corn plantings that are seeded before June 10th are generally not bothered by corn leaf aphids. Monitor for aphids while scouting whorl or pre-tassel stage corn for ECB or FAW in July and August (NE Veg Mgmt Guide).

Funding opportunities for farmers through SARE

Farm Grant calls are out and due November 12th, 2024.  For more information, see the Northeast SARE Farmer Grant Program page. Many Q&A sessions are available on October 8, 16, 22, 30. from 12 to 1 EST. You can register to attend here.

Please sign up for our text service! Text UNHIPM to 866-645-7010 to subscribe.

Contact: Amber Vinchesi-Vahl, UNH Extension State Specialist, Entomology and IPM, Amber.Vinchesi@unh.edu

This program is made possible thought funding provided by the New Hampshire Department of Agriculture, Markets & Food Integrated Pest Management Program. This work is also supported in part by the Integrated Pest Management Crop Protection and Pest Management Extension Implementation Plan from the USDA National Institute of Food and Agriculture.