VPART Pest and Scouting Report

Hi all,

With a long stretch of wet weather being predicted for the region, along with cooler conditions, disease incidence is likely to increase in many crops.   It is important to be pruning any diseased foliage and keeping airflow between plants and rows to reduce the likelihood of disease outbreaks.

Along with an increased probability of disease, storms originating from the south can also carry some unwanted pests up this way. One of the major pests that is transported up to Vermont each year are potato leaf hoppers. Although PLH is not hardy enough to overwinter here in Northern New England, PLHs hitchhike on the winds of storms to the region and quickly establish themselves for the season in alfalfa, beans, potatoes, strawberries, and various other crops. Our team is yet to detect PLH in any of the crops that we are scouting, but considering the frequency of storms and historical arrival dates, I would expect to see them very soon.

This is all to say that it is a good time to start scouting for the PLH adults and small green nymphs. Tapping or brushing plants is one way to check crops for adults (they’ll jump/fly when disturbed), but you’ll need to look on the underside of leaves to find the wingless nymphs. Because nymphs are often the most damaging life stage, early detection is critical. Once the characteristic “hopperburn” symptoms appear, the damage cannot be reversed. As soon as we begin finding PLH in our scouting network, we’ll be sure to let you all know.

The good news with the cooler temperatures and consistent rains is that many insect pest populations have been slower to build this season (e.g. onion thrips). This may allow for a bit of favorable asynchrony between pests and their crop hosts. With any luck, crops may be a bit more hardy and larger to provide some amount of tolerance in the face of pest feeding.

One pest that does not appear to have been slowed by the cooler weather is striped cucumber beetle (SCB). We continue to see high populations throughout the region and are receiving reports from growers struggling to keep adults in check. While both conventional and organic insecticides can provide effective control, cultural practices remain an important part of management. Exclusion netting, resistant or tolerant varieties, and physical feeding deterrents such as kaolin clay (e.g., Surround) can help suppress populations and reduce feeding injury prior to flowering.  Recent research on cucurbit susceptibility in the Northeast revealed the following ranking from most susceptible to least: bitter gourds, winter squash (C. maxima), cucumbers, summer squash, cantaloupe honeydew, butternut winter squash, watermelon.

Though cucurbit plants can often withstand a fair amount of foliar feeding by striped cucumber beetles (SCB), it is important to remember that these beetles are also vectors of bacterial wilt. In most cases, the transmission of bacterial wilt is a greater concern than the feeding damage itself, as infected plants can rapidly wilt and die.

Interestingly, though SCB are vectors of bacterial wilt, transmission of the bacterium does not typically occur directly from feeding and saliva deposition. In reality, the highest concentration and viability of bacterial wilt is found in the frass deposited by beetles as they feed.  Infection primarily occurs when frass comes into contact with feeding wounds on the plant. In theory, removing heavily damaged leaves and beetle frass may reduce opportunities for infection, although this is unlikely to be practical on a large scale. Rain might help!

Furthermore, bacterial wilt tends to wane later in the season. This may be because older cucurbit plants are less attractive to beetles, possibly due to changes in plant chemistry. Mature plants may also be better able to tolerate infection than young plants. As a result, bacterial wilt symptoms may develop more slowly or be less severe in older, larger plants.

In recent years, our team has evaluated a mass-trapping approach for managing striped cucumber beetles in squash production systems. While this strategy has shown promise in other regions, our trials have not yet produced consistent results. Maybe it is us! That said, we’d love to continue to refine the approach and would welcome opportunities to collaborate with growers interested in testing mass-trapping systems on their farms.

Quick notes from the field:

• Leek moth populations in the region are mostly in the cocoon stage, so a new flight will be on the horizon. Check your scapes, they love to feed on them
• First squash vine borer capture in NH, we are yet to see any in VT. More on this next week.
• CPB in VT are bad in most solanums, a bunch of growers are combining trap cropping with flaming + delayed planting.
• Low numbers of corn earworm and European corn borer picking up in MA, NH, PA

As always, our website for the scouting reports can be found here. In addition to the pests reported here, our website also has a more comprehensive list of pests. The list also documents the progression of many common pests as they emerge throughout the season.

For detailed management information about these pests, as well as a comprehensive guide to current  production and pest management techniques for commercial vegetable crops, check out the  New England Vegetable Management Guide. And, as always feel free to reach out to us if you have any questions.

Hi all,

I hope that folks are staying hydrated out in the fields as the unseasonably warm weather has

As mentioned last week, Colorado Potato Beetle (CPB) adults are moving around and we are now beginning to see both egg masses and small larvae. With the recent warm temperatures, these larvae are likely to feed aggressively and develop rapidly. For growers using insecticides, management is generally most effective when targeting smaller larvae, which are typically more susceptible to control measures than larger larvae or adults. It is also important to remember that CPB feeding has the greatest impact on yields when it occurs during flowering and early tuber bulking. Because flowering coincides with the onset of tuber development, protecting plants during this period can help minimize yield losses.

While CPB can affect potato growth throughout the season, the second generation often poses the greatest threat to yield. However, reducing populations early in the season can help suppress subsequent generations and lessen the risk of damaging outbreaks later in the summer.

Swede midge adults have been caught in traps throughout the region, and we assume that midges are now active in brassica fields. Recent research and farmer observations have highlighted some important host preferences for this pest. In most cases, swede midge outbreaks can significantly affect broccoli, collards, Red Russian kale, sprouting broccoli, and Brussels sprouts. Many curly kale varieties, heading cabbages, and Asian greens tend to be less preferred, although damage can still occur when populations are high.

For growers with large investments in brassica crops, insect exclusion netting remains the most effective non-chemical management option. Ideally, netting should be installed immediately after transplanting or seeding and remain in place throughout head development for heading crops. Once larvae enter the growing point, management options become extremely limited and head development is severely impacted.

Spotted wing drosophila has been trapped in Long Island NY and southern NY but we are yet to see any individuals in our traps in Chittenden. We’ll let you know as soon as we see SWD in our traps. For those looking to keep tabs on what is going on in nearby NY, you can always check Cornell Cooperatives Berry Pest Monitoring  Network.

If you are looking to set up SWD monitoring traps on your farm, there are two styles: baited sticky card traps and “drowning” traps. If you choose to use sticky card traps with lures, be sure to use red sticky cards, as they have been shown to be the most attractive. As far as drowning traps Scentry produces a commercial drowning trap or you can simply use diluted grape juice. Research out of UMass Extension has determined that a mixture of diluted grape juice (3 parts water: 1 part grape juice) with 2% (by weight) table salt, fermented for one week, is a cheap and effective bait mixture. You can hang a plastic container (4mm holes near the top) with some of the above concoction in your berry crop and check them weekly for easy monitoring.

Other sightings from around the region:

• Adult squash bugs are beginning to colonize cucurbits in the region.
• Leek moth second flight is yet to begin in VT
• Corn earworm has been caught in the region (MA, NY, NH)
• Cranberry fruitworm traps on a couple of farms are high

Finally, I want to acknowledge and extend gratitude to our newest summer research scouts, Eli Wilson, Darius Parker, Ava Kelly, Heather Boggis, Ella Venus, and Abbey Vranjes . These burgeoning entomologists will be doing a lot of the scouting work for the rest of the season.

As always, our website for the scouting reports can be found here. In addition to the pests reported here, our website also has a more comprehensive list of pests. The list also documents the progression of many common pests as they emerge throughout the season.

For detailed management information about these pests, as well as a comprehensive guide to current  production and pest management techniques for commercial vegetable crops, check out the  New England Vegetable Management Guide. And, as always feel free to reach out to us if you have any questions.

Hi all,

Generally, it looks like pest distributions are starting to align more closely with previous years as I look back at past seasons. We fell behind a bit with the cooler weather, but things have picked up recently.

Unfortunately, after several weeks of clean plants, we are now starting to see some Spinach/Beet leaf miner eggs in some select plantings in Vermont. No huge outbreaks yet but we now have confirmation that they are flying around in the region. If you have struggled with them in the past, you might want to consider covering any plants you want to protect. Scouting for leaf miners, is relatively straight forward. Start by checking the undersides of the leaves. Their small, bright white eggs are usually visible in tight clusters. Leaf mines begin as small, transparent tunnels in the leaf tissue and grow larger as the larvae develop. If you are already seeing mines in the foliage, be sure to remove the “infected” leaves from the field. The larvae feeding in those leaves will eventually make their way to the soil to pupate. Removal of those larvae from the field will reduce the size of the second flight.

Striped Cucumber Beetle (SCB) are also starting to appear in greater numbers. While we are still behind last year’s pace, beetle activity is increasing at a concerning pace in some of the fields we’ve scouted. Keep in mind that SCB shows a strong preference for certain cucurbit species and cultivars. In general, C. maxima varieties such as blue hubbard and summer C. pepo types including zucchini and some summer squash tend to be more highly preferred than C. moschata varieties like butternut and winter C. pepo types such as acorn squash. Though feeding damage can be worrisome for smaller plants and seedlings, SCB are also a vector of bacterial wilt which can be quite a challenge.  If you are putting out any small starts, it might be helpful to employ some kaolin clay to slow the impact of their feeding.

Just prior to posting this report we received word from a local grower near UVM that Mexican bean beetle adults they are seeing a few Mexican bean beetle (MBB) adults in snap beans. This early alert should be helpful for those outside the warmer Burlington area. If you are in the Champlain Valley, it would be advisable to scout your crops over the next week for MBB eggs being laid on the undersides of leaves.

Once bean beetle larvae begin to pop out of their eggs, damage can build very quickly.  Luckily, for those growers interested in using biological control tactics, there is a rather effective option. The parasitoid wasp species, Pediobius foveolatus is commercially available within the region. The wasp is currently reared and sold by the New Jersey Dept of Agriculture and can be purchased from other biocontrol suppliers. For more information on the wasp and ordering directly from suppliers, you can check out the informative UMass website dedicated to the wasp.

Colorado Potato Beetle (CPB) adults are actively moving into fields, particularly onto eggplant and potato. So far, we are seeing mostly adults and very few egg masses. There has been some discussion on the listserv and in other informal grower conversations about non-chemical options for CPB management. Thank you to everyone who has shared ideas with Stony Loam Farm about innovative tactics you are using on your farm, and thanks to  Dave Quickel for getting that conversation started.

Our team has been exploring CPB management strategies extensively over the past couple of years and is hoping to hold a field day or community meeting later this season to discuss shared challenges and successful approaches. If you are interested in joining one of these events, please reach out. We will share specific details as plans are finalized.

Some other quick notes from around the area/region:

• The first leek moth flight seems to be over in the Champlain Valley. You are likely to find most damage in the center of your garlic plants where scapes are beginning to form. You can squish them to reduce the population.
• The first swede midge capture just across the river in Essex County, NY!
• As mentioned last week, Three-lined potato beetle are out and about in just starting to pick up steam. Check your tomatillos if you got’m.
• We’ve seen some onion thrips outbreaks in high tunnels on over-wintered onions. That said, yields have not been particularly affected.

As always you can connect with us via our website: https://go.uvm.edu/vpart. Also, you can now directly submit any pest sightings or questions to our team. Direct emails from the VVBGA listserve are acceptable as well. As always, you can access our pest reports on our website or by directly navigating to the scouting blog.

Feel free to reach out to us if you have any questions.

Cheers,

vic

Hi all,

With the unseasonably warm temperatures over the last few days, pest development has surely advanced, and we suspect that many of the most common early summer pests will soon be moving into fields and high tunnels. Once these pests emerge, pressure tends to increase quickly irrespective of weather.

Pest Week in review

Flea Beetle: Flea beetles are thriving here in Burlington and reports from nearby regions suggest the same as it sounds like they are some large outbreaks in brassica plantings throughout the northeast. Row covers for small seedlings can be an effective strategy for dampening their impact on the sensitive plants.

Colorado potato beetle (CPB) adults are just starting to emerge from their overwintering sites and are just starting to be found in fields and gardens in the Champlain Valley. Today, while collecting wandering CPB adults searching for host plants in last year’s potato field, I was reminded of the importance of crop rotation for CPB management and the potential value of delayed potato planting as a strategy for reducing damage. As mentioned last year, our research team continues to work on a delayed potato planting project and is always interested in hearing from growers who have experience with this tactic, including any tips or approaches that have worked well on their farms.

Our team will also be sharing our experiences with CPB management at several summer and fall workshops and field days that will be announced through these reports, so stay tuned for additional information.These types of cultural controls are becoming increasingly important as reports of pesticide resistance, particularly to organically approved products such as spinosad, continue to become more common. In addition, some growers have developed innovative mechanical tools and implements for in season CPB removal, highlighting the growing interest in integrated and nonchemical management strategies.

A few other highlights from the past week:

Leek moth:  The first flight of leek moth is starting to wane in the warmer regions and we are beginning to see limited leek moth caterpillar feeding damage in garlic. Window paning damage are the primary symptoms that are most recognizable. Generally, economic damage in garlic tends to be limited to scapes, as the larvae tend to feed on the tops of plants. So, if garlic scapes are important for your farm, I would monitor any garlic plantings for leek moth damage to gauge their potential future impact on those scapes.  We expect the next adult flight to begin sometime in mid/late June.

Spinach/beet leafminer:  Though we haven’t seen or heard of any outbreaks in Vermont yet, looking at the degree day model for these leafminers, it seems that they should be flying around at the moment laying eggs on the underside of spinach and chard. As with most leafminers, timely or pre-emptive action is key. Insect exclusion netting is a very effective method if applied before they arrive. The bright white leafminer eggs are relatively easy to spot on the undersides of spinach and chard leaves. Once the larvae get into the leaf they are very well protected from any control strategies. If you are seeing foliar damage, remove and destroy leaves showing active “mines” to reduce future pressure. Be sure to reduce any weeds, particularly lambsquarters, that might act as an alternative host for the pest.

Cucumber beetles have been spotted by several farmers in Chittenden County, though the sitings have been minimal, it is a good to know that they are moving around and soon to be in the field and potentially high tunnels in the near future! Be on the lookout.  I presume we’ll have more to share about them next week.

As always, our website for the scouting reports can be found here. In addition to the pests reported here, our website also has a more comprehensive list of pests. The list also documents the progression of many common pests as they emerge throughout the season.

For detailed management information about these pests, as well as a comprehensive guide to current  production and pest management techniques for commercial vegetable crops, check out the  New England Vegetable Management Guide. And, as always feel free to reach out to us if you have any questions.

vizzo@uvm.edu

Hi all,

As we enter the second week of May and fields begin filling with transplants and direct-seeded crops, several insect pests are emerging from their overwintering sites and searching for suitable host plants.

You can access our website via this link: https://go.uvm.edu/vpart. Also, in an attempt to improve communication with our team, we have added a couple of web forms on our webpage that will allow growers to directly submit any pest sightings or questions to our team. Direct emails from the VVBGA listserve are acceptable as well. As always, you can access our pest reports on our website or by directly navigating to the scouting blog.

Three of the most common maggots that we look for in the region are seedcorn maggot, onion maggot, and cabbage maggot. All of these pests emerge relatively early in comparison to other vegetable pests and are particularly troublesome as they can quickly damage young seedlings, roots, and developing stems before plants become established.  Monitoring and early intervention are therefore critical during this early spring period for susceptible vegetable crops.

While direct scouting for eggs or adults can be difficult for these pests, as they can be quite small. A useful tool for monitoring and predicting the risk level for spring maggots is the Network for Environment and Weather Applications (NEWA) IPM tools website. This site allows you to track the emergence of important pests and diseases using their respective degree-day development models. The number of models available for vegetable production is somewhat limited, but many important fruit pests are included.

According to the current models, we should be seeing adult flies laying eggs in much of the Champlain Valley, as the overwintering generation is between 50% and 100% peak emergence. Cooler central and northern areas have likely not yet seen much emergence, but with warmer temperatures on the horizon, it is important to consider the potential risk. The most important time to protect crops is during the peak emergence of the overwintering generation, especially when plants are small and vulnerable. Growers can target larvae with insecticide-treated seed or an insecticide drench, or prevent damage altogether by keeping egg-laying female flies off plants with row covers. Row covers need to be in place before adult flies begin emerging.

Flea beetles are making their way into brassica crops here in Burlington and across the southern part of the state. Similar to root maggot flies, row covers for small seedlings can be an effective strategy for reducing their impact on the sensitive plants.

In addition to maggots and flea beetles, leek moth adults are also currently flying, as adult moths are being found in relatively high numbers on both sides of Lake Champlain in baited traps. Generally the emerging generation of leek moth seems to inflict less damage than the second generation typically flying in mid-June. This is the result of a combination of few available cultivated hosts and smaller overwintering populations. That said, if you have overwintered onions or other alliums in an area where you’ve had leek moth pressure in previous years it might be useful to take some action to protect smaller plants.

As a reminder you can access our website via this link: https://go.uvm.edu/vpart. Also, there are a couple of web forms on our webpage that allow growers to directly submit any pest sightings or questions to our team. Direct emails from the VVBGA listserv are acceptable as well. As always, you can access our pest reports on our website or by directly navigating to the scouting blog.

For detailed management information about these pests, as well as a comprehensive guide to current  production and pest management techniques for commercial vegetable crops, check out the  New England Vegetable Management Guide. And, as always feel free to reach out to us if you have any questions.

vizzo@uvm.edu

Hi all,

Now that we are in the dogdays of summer, fields look lush and harvest season is fully underway. That lushness, however, also provides potential for the buildup of diseases and pests that can easily hop from farm to farm throughout the region.

One of the concerning updates in the region are reports of late blight in several surrounding states. We are getting reports from western New York and some areas south of Vermont that late blight may be on its way. Despite this concerning news, the silver lining is that we have not heard of any confirmed sightings in Vermont, yet.  However, with some weather systems moving in from the west over the upcoming days, the incidence line may creep a bit closer. So, it is still important to monitor your tomatoes and potatoes for any sign of late blight. Common symptoms on tomatoes and potatoes are greenish-brown lesions on leaves and stems, that are often water-soaked and may be accompanied by white fuzzy fungal growth. These symptoms often come from the top of the plant downward, as the spores are transported via overhead rain. It is especially important to monitor for potential infections after a heavy rain. If you suspect that you may have late blight, be sure to destroy any infected plants as soon as you are confident in your diagnosis. Late blight requires living plant material to survive, so destroying any living infected material will reduce the likelihood for spread to other areas on your farm or neighbors. We’ve been lucky to avoid any outbreaks over the last few years, but we still must be vigilant.

In addition, other diseases to watch for are cucurbit downy mildew (CDM) and basil downy mildew (BDM). There are reports of potential CDM infections in the southern part of the state and areas to the west. Neither of these mildews overwinter here; instead, they arrive with storm fronts from the south. CDM often devastates late cucumber plantings in Vermont, appearing either later in the season or during active storm periods. CDM exclusively affects cucurbit plants, typically starting on older leaves and spreading to younger ones as the infection progresses. As symptoms worsen (via sporulation), the lower leaf surface develops a light grayish-purple “downy” appearance. Lesions can merge, leading to extensive tissue death and exposing fruit to sunscald. Severe infections can cause significant defoliation. Opting for resistant cultivars is the best defense, though conventional fungicides are effective. More information and images are available here: https://ag.umass.edu/vegetable/fact-sheets/cucurbits-downy-mildew

Basil Downy Mildew  (BDM) has been reported in Maine and potentially in other nearby states. Similar to CDM, once established in a field is very hard to manage. It really becomes a situation of damage control, getting rid of any diseased plants in the hopes of saving healthy plants. The reality is, once an outbreak takes hold, there is not much that can be done other than the removal of diseased material.

Also, if you missed Meg McGrath’s recent listserve posting related to BDM research, please refer to the announcement below, as it will help plant breeders to stay informed on the evolution of the disease and its effect on our resistant varieties:

“Researchers at Rutgers (who are part of an international team addressing this) are asking anyone who observes basil downy mildew on their plants in the USA and Canada to send infected leaf samples and to report occurrence to the following website: https://basil.agpestmonitor.org/. These samples will be used to better understand the existing pathogen populations and help drive solutions towards the downy mildew problem. This problem cannot be solved alone! Thank you!!

Shipping Instructions:
Please collect as many infected leaves showing sporulation (or classic yellow leaf banding of this disease) as possible and wrap in a dry paper towel before placing inside a quart-sized ziplock bag. Seal the bag partially (leaving about a quarter open) before placing in an envelope with

Piece of paper with sample source address, basil variety if known, and contact information (email, phone number) in case there are questions about sample.

Mailing Address (regular mail fine as just pathogen’s DNA needed; not live pathogen):
B.A.S.I.L.
Foran Hall, Rm 392
59 Dudley Rd

Rutgers University
New Brunswick, NJ 08901”

Please address any questions or concerns you may have to Rob Mattera (robert.mattera@rutgers.edu)

As far as insect pests, it seems to be more of the same.  Here are a few important notes of those pests.

• Onion thrips populations are really picking up with the dry, hot temperatures. However, the slow buildup earlier this season due to consistent rains has meant there has been little impact on yield so far. Despite seeing increasing damage now, most onions on our monitoring farms are looking great.
• With the extended heat before this recent cooling, Colorado potato beetle populations have shifted so that most of what we’re seeing now are adults emerging from pupation. This may create a good opportunity for potatoes to bulk up without heavy larval pressure. Remember that after flowering, potato plants can tolerate quite a bit of defoliation without significantly impacting yields.
• Lots of our moth pests: armyworms, corn earworms, cutworms, etc, are beginning to show up in increasing numbers in traps and crops in the region. If you have struggled with these in the past, you might want to start scouting for their damage.
• Leek moth trap numbers in most areas are nearly zero, as populations are mostly in the larval stage. You are likely to see damage in your onions and shallots growing over the next week or two. It’s probably fine to remove your exclusion netting on onions, if you are planning to harvest before the next flight (mid August)
• Cabbage whites, aka imported cabbage worm, are showing up in high numbers on lots of farms. For organic growers, Bt and spinosad sprays can be effective, though Bt tends to be more useful while caterpillars are smaller AND it requires the caterpillar to ingest it.

As always, our website for the scouting reports can be found here. In addition to the pests reported here, our website also has a more comprehensive list of pests. The list also documents the progression of many common pests as they emerge throughout the season.

For detailed management information about these pests, as well as a comprehensive guide to current  production and pest management techniques for commercial vegetable crops, check out the  New England Vegetable Management Guide. And, as always feel free to reach out to us if you have any questions.

Hi all,

High temperatures continue to put a lot of stress on plants, leading to symptoms that can take many forms and may be mistaken for diseases. When contacting the diagnostic clinic, be sure to include observations about where and how the issue appears across your planting. This information will help their team more accurately diagnose the problem.

This week we are starting to see a few peaks in pests that have taken a bit longer to build up than the last couple of seasons. One pest that we are now starting to see in greater numbers is the squash vine borer, both in our traps and in plants. While they are often spotty in their distribution in a field, a large population can be quite problematic. The first signs of the pest will often be wilting, which may make you think of bacterial wilt transmitted by striped cucumber beetles. If you start to see some plants wilting in the field, look at the base of the plant and check for any stem damage or some of the insect excrement, also known as frass. That will be the tell for the presence of the pest. If the plant is not completely wilted, it is sometimes possible to do some quick removal of the larvae inside the vine with a knife and some delicate surgery. Once removed, you can try to bury the damaged part of the vine with some soil. If there is enough of a connection left, things may be possible to save.

Leek moth numbers have waned enough on most farms that it is likely safe to start removing any exclusion netting if you have been keeping alliums protected. With garlic harvest in full swing in most areas, be sure to look for the beginning of any larval feeding in the neck of garlic before bringing them into curing and storage areas. Our research has shown that most marketable damage to garlic from leek moth occurs when eggs or larvae hitchhike on the stems and feed down into the bulb as the neck dries down. Topping garlic and/or onions before curing or storage can significantly reduce the risk of post-harvest damage from leek moth in areas with large populations. That said, it is also looking like onion harvest might miss the next flight of leek moth!

Colorado potato beetles are really thriving this year. While high CPB numbers are no surprise in July, we are receiving numerous reports from organic growers about the emergence of spinosad resistant populations. With the loss of the Bt strain for CPB control and a lack of other potential organically approved chemical options, it was just a matter of time before resistance would crop up.

Our team continues to test the efficacy of some organically approved biopesticide options, particularly fungal sprays and some innovative new conventional options. We will keep you posted on the outcomes of those studies. In addition, we are again seeing good results with our delayed planting study. Our late June and early July plantings are showing greater vitality compared to the earlier May plantings, which are mostly sticks at this point. Finally, there are lots of growers using various tractor and human powered whacking and collecting methods. If folks would like to share their methods, it might be useful to collect those suggestions for a VVBGA post, a twilight meeting, or our upcoming UVM Catamount Farm and Field Day (see below).

Regional Roundup:

• Though we are yet to hear of any confirmed incidence of cucurbit downy mildew in cucumber or melons within Vermont, it is just a matter of time, as it seems to be around within the region (e.g. NY, CT).
• Corn earworm, aka tomato fruitworm, is being found on farms in Vermont, with reports of larvae in peppers and tomatoes nearby cornfields. Trichogramma parasitoid wasps can be an effective strategy if timed right.
• Maine is reporting incidence of Basil downy mildew, so be on the lookout in any non-resistant varieties.

Finally, as referenced above,  we wanted to put on your radar an upcoming event at the Horticultural Research and Education in South Burlington:

HREC Farm and Research Field Day

When: August 13, 2025

Time: 2-5pm

Location: Horticulture Research and Education Center (HREC), 65 Green Mountain Dr., South Burlington, VT

UVM’s Catamount Educational Farm, in collaboration with the Department of Agriculture, Landscape, and Environment (ALE), is excited to host a Farm and Research Field Day at the Horticulture Research and Education Center (HREC) on Wednesday, August 13, from 2:00 to 5:00 PM.

We hope you’ll join us for an afternoon of sharing, learning, and connecting with all the research, farming, and outreach happening at the farm!

The day will include:

• Catamount Farm Tour – Explore and learn about the food production systems, educational initiatives, and community partnerships occurring on the farm.
• Field Research Tour – Check out the innovative research projects currently underway at HREC for a host of research projects for vegetable, fruit, and other specialty crop growers.
• Informational Exhibits –

Full Schedule will be sent to registrants and posted to various listservs as the date nears.

This is a great opportunity to connect directly with the diverse group of people working at the intersection of farming, teaching, and agricultural research.

Though registration is not required, if you plan to attend, please submit your name to this form.

Any Questions? Contact Vic Izzo (vizzo@uvm.edu) or Terry Bradshaw (tbradsha@uvm.edu)

For detailed management information about these pests, as well as a comprehensive guide to current production and pest management techniques for commercial vegetable crops, check out the  New England Vegetable Management Guide. And, as always feel free to reach out to us if you have any questions, using our new submission form and/or directly emailing me at vizzo@uvm.edu

Hi all,

Our scout team was on a bit of a break last week, so this report is coming together with a bit of a gap from our last report.

With July upon us, the heat is welcome, but too much of a good thing can become a problem, and this heat is no exception. We’re seeing and hearing reports of significant heat stress symptoms in many crops, especially those grown in high tunnels or other protected systems. The combination of heat and humidity can also make it tricky to tell whether symptoms are due to disease or environmental (abiotic) stress.

One helpful strategy for telling the difference is to look at how the damage is distributed in the crop. If symptoms start in one area and spread outward, it’s likely a disease. If they’re evenly distributed across a section or the whole crop, an environmental factor is probably to blame. And if the damage appears randomly or in a more scattered pattern throughout the planting, it could be the work of a mobile pest like a flying insect.

As far as insects are concerned, we continue to see swede midge damage showing up on several farms. Most of the damage right now is in broccoli and Red Russian kale. The higher pressure in Red Russian isn’t a complete surprise, as our team has identified a particular preference by swede midge for this variety. If you’ve historically had issues with swede midge, it might be wise to steer clear of Red Russian kale.

If you’re planting a fall crop and are already seeing damage in your summer brassicas, you might want to consider using exclusion netting if that’s feasible for your scale. Also, keep in mind that midges can remain in the soil and emerge up to two years after an infestation, so plan your rotations accordingly if possible.

In addition, the Chen Lab at the University of Vermont is looking for growers dealing with swede midge to participate in a study exploring new nonchemical management strategies. If you’re interested, you can email our team directly and we will connect you!

Several growers have reached out to our team to inquire about the current status of Spotted Wing Drosophila (SWD) within Vermont. Our current SWD monitoring program across three counties has been quiet, as we have seen very limited numbers of SWD within our traps. With blueberry picking season beginning, we expect to see increasing SWD trap counts over the next couple of weeks. We will keep you posted on our traps. For those asking about which traps are best for monitoring, we’ve been having great success with the Scentry lures and traps. They seem to outperform most of the trap/lures that we’ve used over the years.

Regional Roundup:

• We have begun to see some Mexican bean beetle pressure on farms and that is a bit later than in previous seasons.
• Colorado potato beetle populations are mostly in their later stages and beginning to pupate in the soil. Folks planting late, may benefit by planting a crop asap, for seed potato at least
• Onion thrips are beginning to build, but the consistent rains have been a help on many farms.
• Diamondback moth is around and causing some damage on select farms.
• Western bean cutworm is being found in traps in NY and NH. Likely around in VT.

For detailed management information about these pests, as well as a comprehensive guide to current production and pest management techniques for commercial vegetable crops, check out the  New England Vegetable Management Guide. And, as always feel free to reach out to us if you have any questions, using our new submission form and/or directly emailing me at vizzo@uvm.edu

Hi all,

I hope things are going well out in the fields as the temperatures begin to really heat up over the next week or so. With high temps come faster generations and more insect outbreaks.

We have some new discoveries this past week of some important pests that are just beginning to be found on farms.

The first spotted wing drosophila (SWD) adult fly of the season was just captured in one of our traps. The good news is that it was only one fly, found in just one of the ten traps. This low level of trapping activity is similar to what’s being observed across the region, so it looks like we’re at the beginning of the SWD season. We’ll keep you posted as the season progresses. For those who want to monitor SWD directly on their own farms, we’ve had great success with the Scentry SWD lures and traps, although they can be a bit pricey. In previous years, we’ve used a diluted grape juice solution for trapping, and that seems to work well too. That said, we’ve generally seen higher trap counts and earlier detections with the Scentry lures, suggesting they may be a bit more effective. A great comparison review of different lures and traps was recently published in the UMass Fruit Notes.

Onion thrips are just starting to show up in onions on our monitoring farms. Populations are still below threshold for now, but with hot weather on the horizon, outbreaks may not be far off. Thrips can be tricky to spot if you’re not familiar with them, but once you know what to look for, they’re pretty easy to identify. We’re mostly seeing yellow-orange juveniles (nymphs) tucked into the crevices at the base of onion plants. As they mature, you’ll start to notice the darker, blackish adults moving around.

In relation to onion thrips management, our team is currently testing a variety of tractor-applied mulches to evaluate their effectiveness in several ways, including their impact on thrips populations. We’re trialing two OMRI-approved paper mulches, black and silver plastic mulches, and a textured silver plastic. We’re also collecting data on soil temperature and moisture, pest management, and basic soil health indicators. Soon, we’ll be adding a prototype manure-based paper mulch made from upcycled manure solids. If any growers are interested in trialing some of the best-performing mulches next season, please reach out to our team. We’ll provide the mulch in exchange for your opinions and feedback on the mulch you’ve selected to compare to your “typical” practice.

Leek moth outbreaks are starting to show up in scapes on select farms in the region. The distribution appears to be patchy, as some farms are getting hammered while others remain mostly clear of leek moth. That said, we’re seeing a lot of pupae (cocoons) in garlic, suggesting that the next flight will likely begin soon. We expect to start seeing adults in traps next week. In terms of management and impact, it’s important to note that we haven’t observed yield losses in garlic or onions due to leek moth, even during severe outbreaks. Most marketable damage in these crops tends to occur during curing or storage, as larvae move down into the bulb away from the drying leaves. Topping garlic and onions before curing and storage can help reduce this risk. However, for leeks and shallots, we do see more direct impacts on yield. In those cases, exclusion netting or well-timed pesticide applications, typically about seven days after peak flight, can be effective. If you have any questions about leek moth, feel free to reach out. Our team has been researching these buggers for quite a while.

One pest that’s surprising us in the region this year is the presence of tortoise beetles in tomatoes across the Northeast. Although we’ve seen them sporadically on some farms in the past, they seem to be showing up more frequently this season. From what we’re hearing, they’re turning into a bit of a nuisance across the board.

We’re not sure what combination of factors has led to this unusual tortoise beetle year, but I wanted to share this in case you’ve been seeing them too. In our experience, they’re not typically a major problem and are hopefully just transient feeders on your plants. One cool thing to look for, if you are seeing them, is the larvae using their “fecal shield” to deter predators. The larvae actually hold their own dried feces over their backs like a little umbrella to ward off would-be attackers.

Other monitoring of note from the region:

• Swede midge damage from the first generation is showing up in brassicas in northern New York.
• Potato leafhoppers have been seen in NY and NH, which likely means they are on their way to VT or already here. We’ll report on them next week, but be on the lookout.
• Leafminer mines are being seen in beet, spinach, and chard in MA. We’re still seeing mostly eggs in VT at the moment.
• Cucumber beetles are in full force around New England.