VPART Pest and Scouting Report

Hi all,

It has been a couple of weeks since our last scouting report. That is a sign that many of the farms we monitor have been heavily into harvest season, and management decisions have largely been determined by this point.

Furthermore, many insect populations have begun preparing for overwintering, which generally leads to a significant slowing of feeding and reproduction. In fact, many of our major pest insects begin this process well in advance of cold temperatures or the removal of their host plants in the field. While temperature does play a significant role in initiating overwintering behavior, day length provides the primary cue. Interestingly, the “critical” day-length period for many Vermont pests begins in late August, right as the thick of harvest season starts. Perhaps this is an outcome of coevolution, helping pest insects avoid being literally “left out in the cold” even though there is still plenty to feed upon. More importantly, this is why we begin to see reduced insect pressure as we move into September, despite a lot of available hosts. In addition, this preemptive overwintering preparation is part of the reason that delayed planting approaches can be an effective strategy for some long-season crops.

In light of this declining pest pressure, I thought that rather than reporting on the general drop in activity within harvested fields, I would put together some information to help growers start prepping for fall and responding to any outbreaks from this past season. I’ve also recently gotten emails and questions not only about when some of our pests begin to overwinter, but where they overwinter.

So, I put together a table featuring most of our common insect pests with that information. I searched around for the best available information on each pest, as the overwintering biology of even our most common pests can be relatively understudied. That said, I hope the table below is helpful! I’ve organized the table into three sections, one for insects that typically overwinter directly or very near the crop field, one for insects leaving the field and residing the winter in other adjacent or distant habitats, and finally those insects that do not overwinter

Also, next week I will be sending out a request for feedback on our scouting reports to help us better support the vegetable and berry community going forward. Thanks, as always, to all the folks who send along their questions, observations, and concerns throughout the season! It  is a valuable opportunity for us to dial in our work.

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

Cheers,

vic

 

 

Pest	Last period of field activity	Overwintering stage	Where it overwinters
OVERWINTERS IN OR DIRECTLY AROUND THE PREVIOUS CROP FIELD
Cabbage maggot	September–October	Pupa	Soil near previous host roots
Cabbage white/imported cabbageworm	Late September–October	Pupa	Attached to plant debris in and around fields
European corn borer	September–October	Larva (Full-grown)	Inside corn stalks, crop stubble, and thick weed stems around field edges
Northern corn rootworm	Late August–September	Egg	Soil of previous corn fields
Onion maggot	September–October	Pupa	Soil near previous host roots
Onion thrips	September–October	Adult	Soil, crop debris, volunteer onions, and weeds
Swede midge	September–October	Pupa	Top two inches of soil in previous brassica fields
Three-lined potato beetle	Late August–September	Adult	Plant debris and protected sites near host plants
Tomato hornworm	September–October	Pupa	Soil below host plants or within high tunnels
Western corn rootworm	Late August–September	Egg	Soil near previous host roots
Winter cutworm	Does not have a clear fall cutoff; active into winter	Larva	Soil, vegetation/debris and protected habitat; can remain active through winter
Other common cutworms	Varies but mostly August-September but some species may remain active until frost	Larva	Many different areas, but commonly in soil below host plants, grass clumps, plant debris and other protected sites
OVERWINTERS IN FIELD EDGES / ADJACENT HABITAT
Colorado potato beetle	Late August–September	Adult	Soil in field margins
Cranberry fruitworm	Late July- Early August	Larva	Protected sites associated with host plants and debris
Flea beetles	September–October	Adult	Soil, plant debris, within field margins
Leek moth	Late August–September	Adult	Crop debris, woodlots, and other sheltered sites outside of field
Mexican bean beetle	Late summer–September	Adult	Leaf litter and protected vegetation
*Spotted-wing drosophila (SWD)	October–November or hard frost	Adult	Leaf litter, hedgerows and wooded/sheltered habitat                                                                                                                                                                                                                                                                                      *There is growing evidence that SWD may not reliably overwinter in VT, where only some more protected populations survive)
Squash bug	September–October	Adult	Crop debris, woodlots, and other sheltered sites outside of field
Tarnished plant bug	September–October	Adult	Plant debris, leaf litter and protected vegetation
DOES NOT RELIABLY OVERWINTER IN VERMONT
Black cutworm	September–October (Until hard freeze)	N/A	N/A
Cabbage looper	September–October (Until hard freeze)	N/A	N/A
Corn earworm	September–October (Until hard freeze)	N/A	N/A
Diamondback moth	September–October (Until hard freeze)	N/A	N/A
Fall armyworm	September–October (Until hard freeze)	N/A	N/A
Potato leafhopper	Late August–September (Until hard freeze)	N/A	N/A
Variegated cutworm	September–October (Until hard freeze)	N/A	N/A

 

Hi all,

We are entering peak harvest season for many crops in the region, and as a result some insect populations, despite their presence are becoming less of an issue. That said, as Ann Hazelrigg indicated in her recent post, disease incidence often increases as we get a bit later into the season and temperatures cool down and leaf wetness persists as evaporation slows on plants in the field. If you missed Ann’s post, you can search for her post via the listserv archive. That said, it is still important to monitor for some pests as there are some that can really be problematic later in the season.

One pest that begins to show signs of impact later in the season, and that we are seeing a bit of on farms right now, is the pepper maggot. This fly pest is related to several other agricultural pests, including apple maggot, blueberry maggot, and cherry husk fly. These flies can be easily spotted on yellow sticky cards, as they have ornate black striping on their wings. While it can be difficult to distinguish among these species, if you are seeing flies with black-striped wings around your pepper plants, it is likely that you have pepper maggot.

Pepper maggot flies typically begin emerging as adults in late July and lay eggs through most of August in the Northeast. Females lay their eggs on the sides of pepper fruit, leaving visible brown or black egg-laying scars. Once the maggots enter the pepper, they are well protected from most pest management tactics. This means that any insecticide application needs to be timed during the egg-laying period, before the maggots enter the fruit. For farms with a history of pepper maggot, monitoring with yellow sticky cards can help determine when flies are active and inform the timing of applications. There are also a couple of effective non-chemical options for reducing pepper maggot pressure, including crop rotation and trap cropping. Because the pest overwinters as pupae in the soil below its host plants, rotating peppers as far away as possible from previous infestations can be an effective strategy. For protecting sweet peppers, it is also well established that pepper maggot flies prefer to lay their eggs on spicy peppers, particularly hot cherry peppers, over bell peppers. In fact, it has been documented that a perimeter trap crop of hot cherry peppers can reduce pepper maggot pressure by up to 98% in interior bell pepper crops.

Another later-season pest that we are seeing in relatively high abundance right now is another fly, spotted wing drosophila (SWD). Our monitoring traps are beginning to show high numbers of male flies with their characteristic black spots on their wings. Females are much harder to monitor, as they do not have spots on their wings and require some form of magnification to identify their saw-like ovipositor, or egg-laying appendage. Importantly, males tend to show up later than females in traps. This means that by the time you are seeing males in your traps, there is a good chance that your fruit may already contain larvae. Including our own trap counts, we have received reports from quite a few growers that they are seeing signs of SWD in their later blueberry varieties, so we are really beginning to enter the high season for this pest.

Though insecticide applications can be relatively effective when properly timed, consistent harvesting to reduce the amount of time fruit spends in the field, followed by refrigeration, can also help reduce the impact of SWD on the saleability of fruit. Refrigeration can kill larvae that are already present in harvested fruit and is an important post-harvest management tool.

Some other notes from around the region:

• Corn earworm trap numbers high in the region
• Flea beetle beginning to pick up from the hot summer lull
• SWD (as mentioned above) is picking up all over the region
• Potato leaf hopper damage has really picked up as farms with infestations are seeing quite a bit of hopper burn.

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

Cheers,

vic

Pest	Crop			Observations
Pepper maggot	Bell peppers			We are seeing some peppers with ovipositional scars, and some growers are reporting maggots in fruit
Potato Leafhoppers	Beans			Seeing mounting hopper burn where populations were high
Colorado Potato Beetle	Potatoes			Most potatoes are not seeing issues from the final generation
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			Not seeing any
Striped Cucumber Beetle	Squash/Cucumber			Cucumber beetle pressure is not very high right now
Flea Beetle	Broccoli/ Kale			Pressure is certainly picking up in newly planted brassicas
Three-lined potato bug.		Tomatillos	Dwindling pressure
Mexican bean beetle		Beans	Still limited distribution.
Leek Moth		Onions/Garlic	Third flight is picking up, so egg laying is likely occuring
Spotted Wing Drosophila		Berries	We are moving into peak trap counts on many farms
Swede Midge		Brassicas	Seeing consistent damage on most farms, mostly in more susceptible varieties of brassicas (red Russian kale, sprouting broccoli, brussel sprouts.
Squash Vine Borer		Cucurbits	Still seeing consistently high numbers
Squash Bug		Summer squash	Consistent pressure, and now with the high number of adults we are seeing symptoms
Onion thrips		Onions	Damage is peaking but yields seem ok in most plantings.

 

 

 

Hi all,

We had a one week hiatus from our scouting blog last week as much of our crew was on vacation. We were back in the fields this past week, and the consistent rains across much of the region have resulted in a spike in many leaf spot diseases, particularly in cucurbits. This is no surprise given the high humidity and consistent leaf wetness. Interestingly, we are not seeing as much powdery mildew as we have in previous years, nor are we seeing much septoria or other fungal disease pressure in tomatoes around the region. Perhaps this is because even when it has rained, it has often been followed by periods of intense heat that quickly evaporate moisture from leaf surfaces, reducing the opportunity for some diseases to establish.

Speaking of tomatoes, we are seeing a large surge in tomato/tobacco hornworms pressure in almost all of the tomato crops that we have been scouting. So, it is that time of year when you can dust off that 80s blacklight for the good of IPM! Yes, tomato and tobacco hornworms are becoming common throughout the region, and several farmers are reporting heavy infestations. One of the more fun and effective ways to scout for hornworms, especially in high tunnels, is to use a blacklight flashlight at night. Under ultraviolet light, the cuticle of hornworms fluoresces, making these otherwise well camouflaged caterpillars easy to spot and remove by hand. This approach is often much more effective than searching during the day, when hornworms blend in remarkably well with the foliage. By the time they become large enough to find easily in daylight, they have often already caused significant damage.

There are also some excellent native natural enemies of hornworms, particularly the parasitoid wasp Cotesia congregata, that can help suppress populations. Providing a continuous supply of small flowering plants throughout the season helps support these beneficial wasps. Research has shown that buckwheat is an excellent floral resource for C. congregata (as well as hover flies), with wasps feeding on buckwheat nectar exhibiting longer lifespans. For organic growers, products containing Bacillus thuringiensis (Bt) remain a very effective management option when caterpillars are small.

As we mentioned previously, swede midge pressure continues to be spotty across the region, but where it occurs it can be relatively severe. This season we have observed swede midge damage in several plantings of red cabbage. Historically, we have been less concerned with swede midge in cabbage compared to other brassica crops because the growing point becomes protected as the cabbage head develops. However, it has been interesting to see noticeable injury in red cabbage this year. This may simply reflect the timing of the population peak, but it is something we will continue to monitor. One of the rewarding aspects of this scouting program is that we are constantly learning new things about these pests as we observe them across different farms, production systems, and environmental conditions.

Another observation that has become increasingly consistent is that sprouting broccoli appears to be a relatively good host for swede midge. Our team has now documented this on several farms, particularly as sprouting broccoli has become more popular among growers in the region. Although swede midge injury appears to be more common in sprouting broccoli than in traditional heading broccoli, at least anecdotally, growers can often harvest around the damaged shoots and still produce a marketable crop under moderate infestations. We are planning another brassica swede midge trial next year to investigate some of these new observations more systematically, and we will be sure to keep you posted.

Also, as our team has been exploring best practices for delayed planting in potatoes to reduce Colorado potato beetle (CPB) pressure, we have heard from many growers, and observed on several of our scouting farms, that they are trying the technique. In addition, our delayed planting research trials are up and running as we speak. In most cases, delayed plantings are showing a significant reduction in CPB pressure. This is encouraging news and is in line with what our previous trials have shown.

A couple of important things are worth noting. First, we have primarily conducted these trials with day neutral or earlier season potato varieties to ensure there is ample time for the tubers to size up and develop a viable skin before harvest. Also, greensprouting can support this technique, as holding seed potatoes for an extended period under less than ideal conditions can lead to reduced germination rates and plant vigor. Greensprouting can help offset these issues while still allowing growers to delay planting. That said, if you are currently using delayed planting as part of your IPM strategy for managing CPB, we’d love to hear from you! We are planning to conduct an information session this fall or winter to share the results from our recent trials, discuss plans for new experiments to further dial in the technique, and collect grower input on their experiences. Hopefully, this will lead to a useful fact sheet to support both current users of the practice and growers interested in trying it.

 

Notes from around the region:

• Potato leaf hoppers are being found in the region on many farms
• Leek moth is beginning a third flight, consider topping if you have had significant pressure this year
• Corn earworm is spiking in the region
• Onion thrips damage has picked up, along with onion downy mildew, but yields on most farms has not been affected

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

Cheers,

vic

Pest	Crop			Observations
Potato Leafhoppers	Beans			Populations are peaking in plantings where they have been found
Colorado Potato Beetle	Potatoes			Pressure is dwindling
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			Relatively little to no damage this season
Striped Cucumber Beetle	Squash/Cucumber			Beetle populations are less apparent and not causing as much damage. It is also a bit difficult to scout with canopies so dense
Flea Beetle	Broccoli/ Kale			Pressure is picking up in newly planted brassicas
Three-lined potato bug.		Tomatillos	Pressure is declining
Mexican bean beetle		Beans	Still limited distribution.
Leek Moth		Onions/Garlic	Third flight is beginning
Spotted Wing Drosophila		Berries	Catching a few more these weeks, but populations seem smaller than past years
Swede Midge		Brassicas	Seeing consistent damage on most farms, mostly in more susceptible varieties of brassicas (red Russian kale, sprouting broccoli, brussel sprouts.
Squash Vine Borer		Cucurbits	Still seeing consistently high numbers
Squash Bug		Summer squash	Consistent pressure
Onion thrips		Onions	Damage is peaking but yields seem ok in most plantings.

 

Hi all,

As we move into the last week of July, many insect populations are entering their second generations, and pest damage in many maturing crops is beginning to show signs of a second round of feeding. Fortunately, many of these crops are at growth stages where they can better tolerate pest damage and weed competition. That said, direct damage during the later stages of crop development can still affect marketability.

One pest that is beginning to show the impact of its second generation is the leek moth. The majority of onion crops we have been monitoring are now showing signs of leek moth damage, and in some cases, we are seeing damage in upwards of 30–40% of onions within a field. However, much of this damage is not affecting yields, as the characteristic “window-paning” damage generally does not significantly reduce the amount of viable leaf tissue.

In addition, as many farms are harvesting garlic these days, be sure to inspect plants for signs of leek moth larvae crawling around on the tops prior to moving them into curing. Larvae can potentially move down toward the bulb to feed as the tops dry down, increasing the potential for bulb damage. Alternatively, topping garlic prior to curing and storage can remove any opportunity for leek moths to hitchhike into curing or storage areas. That said, topping is unnecessary if you do not see any signs of leek moth prior to harvest.

For those folks with berries, we have caught our first spotted wing drosophila (SWD) adult in our monitoring traps. Though this signals the beginning of the seasonal SWD infestation period, a single female out of nearly 20 traps on farms in the area is not a huge reason for concern. This is the latest that we have caught our first SWD in a trap in many years. This may be the result of a harsh winter knocking back populations in the fall, combined with the recent dry spell on many of the farms where we monitor. Regardless, this is a welcome result, as the smaller and slower SWD buildup may reduce pressure on this year’s blueberry harvest.

One pest that is causing significant damage on several farms right now is the imported cabbageworm (ICW), or cabbage white. Across many of the farms that we monitor, we are seeing high levels of ICW leaf damage, and in some cases, this has been severe, as we are seeing rather large caterpillars in most plantings. Monitoring directly for ICW caterpillars can be a bit difficult, as they are easily camouflaged by their green color on green brassicas. If you are looking for ICW caterpillars, be sure to carefully inspect the undersides of leaves, where they may be hiding, particularly the midrib of larger brassica leaves. For organic growers, Bt can be an effective chemical application, just be sure to get good coverage on leaves where caterpillars are feeding, as it needs to be ingested by the pest to be effective.

Notes from around the region:

• Squash vine borer peaking in most areas in the northeast
• Swede midge damage in brassica crops across the region
• Tarnished plant bug are thriving in many crops
• Fall armyworm, corn earworm, and European corn borer are all being found in traps in New York and NH, though the numbers are variable across the region.
• Onion thrips damage is high on many farms as the dry and hot weather continues.

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

Cheers,

vic

Pest	Crop			Observations
Potato Leafhoppers	Beans			Higher pressure this week. Lots of nymphs and adults in beans, less pressure in potatoes at the moment.
Colorado Potato Beetle	Potatoes			Mostly late stage larvae and fewer adults
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			Some signs of limited leaf damage beginning to mount these days
Striped Cucumber Beetle	Squash/Cucumber			Beetle populations are still really large on many farms.
Flea Beetle	Broccoli/ Kale			Very low and mostly inconsequential these days.
Three-lined potato bug.		Tomatillos	High pressure in most areas.
Mexican bean beetle		Beans	Still limited distribution.
Leek Moth		Onions/Garlic	Second flight is mostly over, but we are seeing high amounts of leaf damage as most populations are in their larval or pupal stage
Spotted Wing Drosophila		Berries	Caught our first adult in a trap this week. Only one so far.
Swede Midge		Brassicas	Seeing consistent damage on most farms, mostly in more susceptible varieties of brassicas (red Russian kale, sprouting broccoli, brussel sprouts.
Squash Vine Borer		Cucurbits	High trap numbers, populations are peaking
Squash Bug		Summer squash	Both adults and nymphs are starting to thrive
Onion thrips		Onions	High pressure in many onion crops at scouting sites. Seeing lots of damage these days

 

Hi all,

Not a ton of new pests to report this week. It’s very much more of the same, with several pest populations continuing to build around the region.

Onion thrips populations have been building over the past couple of weeks, and this past week we began to see some large outbreaks. Populations have surpassed economic thresholds in most plantings, likely due to the recent stretch of hot and dry weather. Thrips can be tricky to spot if you’re not, but once you know what to look for, they’re relatively easy to identify. Damage from onion thrips typically appears as silvery streaking on the leaves. While we do not typically see significant yield losses from thrips feeding alone, the damage can weaken plants and make them more susceptible to secondary diseases or other pests. Consistent rainfall can help reduce thrips populations, but if rains arrive after a thrips outbreak, the damaged foliage may be more vulnerable to disease development.

In recent years, many growers have begun using silver plastic mulch to discourage thrips establishment. Research does support its use, and our team is currently evaluating several tractor-applied mulches, including silver plastic, to better understand their effects on thrips populations and other crop pests. We are comparing two OMRI-approved paper mulches, black and silver plastic mulches, and an upcycled manure paper mulch that we have developed. This year, about 10 growers are participating in the project, and we are excited to get their feedback on these new mulch options. Hopefully, we will have some data to share with you all by the end of the season!

One final note on allium pests: we have received several questions about potential allium leafminer (ALM) damage in onions and garlic. Fortunately, we were able to rule out these suspected cases based on the pest’s seasonal biology. For those concerned about ALM in their summer onions or garlic, it is important to know that the insect is currently in a summer dormant period, which begins in June. During this time, the pest is inactive and adults will not emerge until the fall, so they are not causing damage in crops right now. It is also worth noting that we have yet to confirm a validated occurrence of allium leafminer in Vermont, so there is no evidence that the pest has become established in the state.

As mentioned last week, swede midge outbreaks are beginning to appear on several farms that we are monitoring. If you are in the process of planting fall brassicas, or planning to do so soon, it would be a good idea to scout any brassicas that are currently growing in your fields. If you are finding swede midge damage, deploying insect exclusion netting for your latest succession can go a long way toward reducing pressure on your fall crop.

 

Notes from around the region:

• Our spotted wing drosophila (SWD) traps are still clear on the farms that we are monitoring, but there have been positive trap catches across the lake in New York. Even there, however, numbers have been uncharacteristically low for this time of year.
• Squash bug populations are booming across the region.
• Fall armyworm and western bean cutworm have been captured in pheromone traps in neighboring states.

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

Cheers,

vic

 

Pest	Crop			Observations
Potato Leafhoppers	Beans			Starting to see more nymphs and spreading to other crops.
Colorado Potato Beetle	Potatoes			All life stages are being seen on farms.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			No reported damage these days..
Striped Cucumber Beetle	Squash/Cucumber			Beetle populations are still really large on many farms.
Flea Beetle	Broccoli/ Kale			Very low
Three-lined potato bug.		Tomatillos	High pressure in most areas.
Mexican bean beetle		Beans	Still limited distribution.
Leek Moth		Onions/Garlic	Second flight is well underway and feeding is being seen
Spotted Wing Drosophila		Berries	Still are yet to find any adults in our traps but we expect soon
Swede Midge		Brassicas	Seeing consistent damage on many farms
Squash Vine Borer		Cucurbits	Numbers are picking up in traps
Squash Bug		Summer squash	Both adults and nymphs are starting to thrive
Onion thrips		Onions	High pressure in many onion crops at scouting sites.

 

 

 

Hi all,

It looks like a very similar pattern to last year, with July bringing hot and dry conditions following a wet May and June. As we mentioned last week, this can be a mixed bag for pest and disease pressure. While hot and dry weather may slow the development of some diseases and insects, prolonged heat and drought can increase stress on crops. Extreme weather of any kind can also lead to unexpected or difficult to diagnose problems. Heat and drought stress can lead to symptoms that may mimic insect feeding or disease. That makes our job as scouts a bit more complicated, but we’ll still be out there each week doing our best to help identify issues and keep you informed.

After several weeks of encouraging growers to scout their beans and potatoes for potato leafhoppers (PLH), we saw several small outbreaks in beans on a couple of diversified vegetable farms this past week. This is a bit later than the past couple of years but falls in line with the general arrival time observed over the past decade. Although we are only seeing them in beans at the moment, potato leafhoppers have an extensive host range, feeding on more than 220 plant species, including both cultivated crops and non-cultivated or weedy species. The majority of these hosts (close to 62%) belong to the legume family, so perhaps they should really be called the bean leafhopper!

As mentioned previously, each spring potato leafhoppers migrate from their overwintering areas in the southeastern United States to northern regions of the U.S. and eastern Canada. Once they arrive and establish in bean and potato plantings, they typically complete two generations during the growing season. Interestingly, they begin preparing for their return migration rather early here in the Northeast. Previous studies have estimated that adult females begin preparing for their journey south as early as mid-August. At that point, female leafhoppers leave cultivated fields, stop laying eggs, and begin hitchhiking on favorable weather systems back to their overwintering regions in the Southeast.

While nonchemical controls for potato leafhoppers are most effective before they arrive and become established, growers with bean plantings that can be covered with insect exclusion netting may be able to delay or reduce infestations. Once a population is established in a crop, several conventional insecticides provide very effective control. For organic growers, field research suggests that pyrethrin- and neem-based products can reduce potato leafhopper pressure.

In addition to potato leafhopper, our team has uncovered several swede midge outbreaks in brassicas across the Champlain Valley and central Vermont, including Washington County. Swede midge is one of the more frustrating brassica pests, as it can decimate a crop if an outbreak coincides with the early stages of head formation in broccoli, cauliflower, and even Brussels sprouts. In recent years, we have noticed that many growers have begun planting sprouting broccoli as an alternative to heading broccoli. Unlike heading broccoli, swede midge damage to sprouting broccoli does not typically result in a complete loss of marketable yield, as the plants continue to produce side shoots and florets even after the growing tip has been damaged. This appears to be a good adaptation strategy, and we’ve heard positive things from several growers who have adopted this approach.

That said, anecdotally, we have been observing much higher levels of swede midge damage in sprouting broccoli plantings than in heading broccoli when scouting farms growing a diversity of brassica crops. Despite the increased damage, however, growers still seem to be harvesting respectable yields from these plantings. It makes us wonder whether sprouting broccoli could be functioning as a trap crop in these scenarios. It’s an intriguing possibility, and one we’d like to explore next season, if any farmers are interested?

Important notes from the region:

• Still are yet to see any spotted wing drosophila (SWD) on any of the farms that we monitor. We expect to see them soon.
• Sqaush bugs are beginning to pick up steam in summer squash plantings.
• Onion thrips are around but populations, in general have been spotty across fields. We’ll see if this pattern continues with the dry heat that is on the horizon.

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

Cheers,

vic

Pest	Crop			Observations
Potato Leafhoppers	Beans			Seeing mostly adults and few nymphs.
Colorado Potato Beetle	Potatoes			All life stages are being seen on farms.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			No reported damage these days..
Striped Cucumber Beetle	Squash/Cucumber			Beetle populations are really large on many farms.
Flea Beetle	Broccoli/ Kale			Very low
Three-lined potato bug.		Tomatillos	High pressure in most areas.
Mexican bean beetle		Beans	Still limited distribution.
Leek Moth		Onions/Garlic	Second flight is under way and egg laying is occuring
Spotted Wing Drosophila		Berries	Still are yet to find any adults in our traps
Swede Midge		Brassicas	We have seen several outbreaks in sprouting broccoli and red Russian kale.
Squash Vine Borer		Cucurbits	Numbers are picking up in traps
Squash Bug		Summer squash	Nymphs are starting to be seen in high numbers
Onion thrips		Onions	Still low pressure!

 

 

 

Hi all,

This week’s scouting report is a bit later than usual after the holiday weekend, but we were able to get out and scout before the heat set in.

With the extreme temperatures, monitoring for insects can be both uncomfortable and somewhat futile, as insects, like us humans, are generally less active above certain temperatures. In fact, while we often think of insect development as being driven by temperatures rising above a lower developmental threshold, the opposite is also true for most insects. For the majority of insects in our region, temperatures above roughly 90°F will slow or even arrest development in much the same way that temperatures below their lower threshold do. Keep this in mind when thinking about how a heat wave affects insect populations.

As far as what we saw the past week, one insect that we are starting to see in our traps is the squash vine borer. Though we are seeing low counts in our traps, they have been caught which signals, that you should be considering the possibility of SVB in squash fields when you see a plant that wilts out of nowhere. The primary sign of SVB is the wilting of squash plants in the summer heat. With a closer inspection, you can find tunneling within the vines at the base of the plant. 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.

Exclusion netting can be useful for excluding moth from plantings, though this strategy is only useful prior to flowering and the need for pollinators. Well-timed applications, chemical and non-chemical (e.g. diatomaceous earth), near the base of plants during the early stages of flights can be useful. Traps with SVB lures can often provide growers with a good resource for timing controls for their specific farm.

Leek moth adults are starting to peak around the region, as we are seeing high counts in most traps.  Eggs are currently being laid on onions and other alliums, and we expect them to hatch within the next week, leading to larval feeding. Look for signs of leek moth caterpillar feeding, often recognized by “window-paning” in onion crops. For effective chemical controls, it’s best to apply treatments about 7 days after the peak, which should align near the end of this week for growers in the Champlain Valley.  It is also important to keep an eye on the stage of the leek moth population before harvesting garlic. If you cure or store garlic with the tops still attached, you don’t want to bring larvae or eggs into your curing or storage facilities. This is less of a concern if you are topping before curing or storage.

Important notes from the region:

• Spotted wing drosophila trap counts in New York are low but catches have occurred in Saratoga and Essex County. So far no SWD in our Vermont traps.
• Sqaush bugs are in all lifes stages (adults, eggs, nymphs) in squash plantings
• We are seeing limited onion thrips in onion but with the dry and high heat that is predicted over the next couple of weeks, we expect to see an increase in pressure.

 

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

 

 

 

Pest	Crop			Observations
Colorado Potato Beetle	Potatoes			All life stages are being seen on farms.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			No reported damage these days..
Striped Cucumber Beetle	Squash/Cucumber			Beetle populations are really large on many farms.
Flea Beetle	Broccoli/ Kale			Very low
Three-lined potato bug.		Tomatillos	High pressure in most areas.
Mexican bean beetle		Beans	Still limited distribution.
Leek Moth		Onions/Garlic	Second flight is under way
Spotted Wing Drosophila		Berries	Still are yet to find any adults in our traps but there are traps just across the lake in Northern New York counties
Swede Midge		Brassicas	Still have not seen any damage, but there are positive identifications in traps in the region
Squash Vine Borer		Cucurbits	Adults being trapped in VT. Small numbers.
Squash Bug		Summer squash	Seeing nymphs, eggs, and adults.
Onion thrips		Onions	Low pressure thus far.

 

Hi all,

Some lovely weather over the past week, ended again with some heavy storms and rain here in the Champlain Valley and much of the upper half of the state. Given the consistent rains and cooler temps these weeks, we anticipate an increase in disease incidence, so it’s important to keep an eye out for any sick plants or signs of fungal diseases (e.g. mildews, etc.).

As mentioned last week,  potato leaf hoppers are likely on their way or may already be here. We have received reports of PLH in Massachusetts, and the recent storms originating from the south may have helped carry them into Vermont. Although our team has yet to detect PLH in any of the crops we are scouting, with reports so close to us, I imagine there are likely fields already harboring the pest.

Be aware that PLH can feed on a wide range of host plants, but they particularly favor legumes and potatoes. Because they have such a broad host range, they are often induced to move into crop fields during mowing. It is therefore especially important to scout beans and potatoes located near recently mowed fields.

The earlier you detect PLH, the easier it is to reduce their impact with insecticide applications if treatment becomes necessary. For smaller plots or garden beds, insect exclusion netting or other types of row cover can help protect young plants until flowering. For potatoes, there is some evidence that earlier season varieties tend to be more susceptible to PLH damage and associated yield losses than later season

Mexican bean beetle adults have been reported by farmers and gardeners at several locations near our scouting farms in Chittenden County. For folks with a large investment in bean crops, it is advisable to get out there and scout a bit. Once bean beetle larvae begin to pop out of their eggs, damage can build very quickly.  For growers utilizing IPM approaches, there is a rather effective biological control option available.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 like arbico, IPM labs, etc.

Instances of three-lined potato beetles are increasing in many fields, particularly in Chittenden County. Despite their name, these pests rarely feed on potatoes, preferring tomatillos and ground cherries instead, with tomatillos being their favorite host.

They are often mistaken for striped cucumber beetles because of their similar striped pattern but can be distinguished by their orange-red head and legs. Another helpful way to tell them apart is by looking at the larvae. The yellow larvae of the three-lined potato beetle feed openly on the leaves of their host plants and famously cover themselves with their own feces as protection from predators. In contrast, striped cucumber beetle larvae feed below ground on plant roots, so if you see larvae feeding on leaves, they are not cucumber beetles.

Insect exclusion netting or row cover can effectively protect susceptible crops from three-lined potato beetles. Netting also allows plants to become well established before beetles arrive. In general, healthy, vigorous plants that are larger prior to infestation are much better able to tolerate feeding, and yield losses are often greatly reduced.

 

Quick notes from the field:

• Leek moth populations are beginning to start their second flight and are laying eggs.
• Caught our first squash viner borer in Burlington. More next week.
• Potato leaf hoppers have been seen in MA. Potentially are here in VT.
• European corn borer has been found in corn in Burlington. Check your plants for the characteristic line of “shot holes”

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

Pest	Crop			Observations
Colorado Potato Beetle	Potatoes			CPB larvae are feeding and impacting crops! Late instars make up most of the populations
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			Very limited. Seeing few mines.
Striped Cucumber Beetle	Squash/Cucumber			Beetle populations are really large on many farms.
Flea Beetle	Broccoli/ Kale			Pressure is consistent but less than the beginning of the season
Three-lined potato bug.		Tomatillos	They are being reported in region the distribution is still spotty
Mexican bean beetle		Beans	Limited in distribution, but we have some big outbreaks where they are being seen
Leek Moth		Onions/Garlic	Mostly still in pupal stage, new flight to begin soon
Spotted Wing Drosophila		Berries	Still are yet to find any adults in our traps.
Swede Midge		Brassicas	Midges have been trapped but no damage has been seen. Likely to begin seeing damage over the next couple of weeks be sure to check sprouting broccoli
Squash Vine Borer		Cucurbits	Trapping of a few adults in NH
Squash Bug		Summer squash	Have just started to see adults

 

 

 

 

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

Pest	Crop			Observations
Colorado Potato Beetle	Potatoes			CPB larvae are feeding and impacting crops! Late instars make up most of the populations
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			Very limited. Seeing few mines.
Striped Cucumber Beetle	Squash/Cucumber			Beetle populations are really large on many farms.
Flea Beetle	Broccoli/ Kale			Pressure is consistent but less than the beginning of the season
Three-lined potato bug.		Tomatillos	They are being reported in region the distribution is still spotty
Mexican bean beetle		Beans	Still limited to one or two farms at the moment
Leek Moth		Onions/Garlic	Mostly still in pupal stage, new flight to begin soon
Spotted Wing Drosophila		Berries	Still are yet to find any adults in our traps.
Swede Midge		Brassicas	Midges have been trapped but no damage has been seen. Likely to begin seeing damage over the next couple of weeks be sure to check sprouting broccoli
Squash Vine Borer		Cucurbits	Trapping of a few adults in NH

 

 

 

 

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.

Finally, we would also like to acknowledge that funding for this year’s scouting program has been generously granted by VVBGA and the USDA Transition to Organic Partnership Program

 

Pest	Crop			Observations
Colorado Potato Beetle	Potatoes			CPB larvae are now feeding and defoliating
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets			Adult flies are flying and laying eggs. Though populations seem to be limited
Striped Cucumber Beetle	Squash/Cucumber			Beetle populations are really picking up in most stands of cucurbits
Flea Beetle	Broccoli/ Kale			Pressure is consistent but waning
Three-lined potato bug.		Tomatillos	They are being reported in region the distribution is spotty
Mexican bean beetle		Beans	Still limited to one or two farms at the moment
Leek Moth		Onions/Garlic	We are still seeing larval feeding, mostly in center of garlic and on new scapes.   Our traps are mostly clear, so the first flight is over
Spotted Wing Drosophila		Berries	Though we have not trapped any in our traps, there have been sightings in Long Island and Southern NY
Swede Midge		Brassicas	Midges have been trapped but no damage has been seen.