VEPART Pest and Scouting Report

Hi all,

As we pass the halfway mark of August, many growers are already beginning to think about next year! For some, many of the pests that we’ve seen throughout the season have done their damage and are now just a part of this season’s history. That may be the case for most pests but there are still some pests that are rebounding and/or have grown large enough to cause greater damage.

 

In general, there aren’t many new pests to report on this week. Though, here are a few notes from the field this past week:

 

• We’ve been monitoring Basil Downy Mildew since reports of the disease popped up rather early in the season. It now seems that the disease is being found in and around Burlington and likely is prevalent in other areas. As a reminder, BDM is a pathogen that blows in from the south each year and 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 can be done. Also, a reminder that the Ag Pest Monitoring Site for basil is a great resource for identifying, reporting, and managing BDM.  If you suspect that you are seeing BDM, please send us a message and/or send a sample to the Plant Diagnostic Clinic here at UVM.

 

• We continue to get reports of various Tomato leafspot diseases (Septoria and Alternaria) in the region. This is no surprise and is generally expected as the season marches into the later parts of the summer with higher humidity and summer rains. Cultural controls (e.g staking, drip irrigation, keeping up fertility , etc.) can be effective strategies and may minimize large outbreaks. The recent dry weather will slow the spread of the disease but with each rain, the fungus will move higher in the crop canopy. We’ve been lucky to avoid late blight, despite its arrival in Canada several weeks ago. There have been reports out of Maine regarding “air samples” of late blight spores, but no confirmed plant infections. So that is good news, all considering. We encourage growers to stay vigilant and report any potential late blight signs.  

 

• Over the past week, we’ve gotten reports from several farmers that flea beetles are rebounding (in a major way) in many brassicas. Provided the dry and relatively mild summer temps (excluding a few days in early August), it is not a complete shock that we’re seeing larger than normal flea beetle pressure for this time of the year. Typically, flea beetle populations begin to wane during the hot and humid parts of the summer.  Temps in the 90s, combined with humid/rainy conditions can suppress their populations. It may be counterintuitive that higher temps would slow insect populations, but it is important to note that insects have both a lower and upper threshold temperature range for development.  Flea beetles typically do very well under hot (but not too hot) and dry conditions. This season, for much of the region, we have experienced the perfect storm for consistent flea beetle pressure. Insect exclusion netting is great for controlling flea beetles during the hotter times of the season, as it has less insulating capacity (i.e. R-value) than remay, but it may be fools gold for late season usage. Flea beetle larvae feed upon the roots of plants, and the netting may simply trap emerging adults.

 

• Swede midge populations seem to be building in many brassicas that we’ve been monitoring. Damage is being seen in a variety of brassica plantings and in some case it has been severe.  Broccoli, cauliflower, kohlrabi, and collards are generally consider the most susceptible brassica crops and should be the most closely monitored. Be on the lookout for swede midge signs, like twisted leaves, scarring, and/or dead heads (not the tie-died kind).

 

Finally, reports from squash vine borer trapping programs in the region suggest that SVB population numbers are falling within the area and the risk from the pest is waning.  We’re not out of the woods quite yet, but the falling numbers is a good sign.

 

As always you can find more details on other pests and diseases at our pest and scouting website.

 

Thanks to all of the growers that have reached out with their own questions and pest scouting information. All information and questions help us to better serve the needs of the VVBGA community.

 

Cheers,

The VEPART team

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	CPB continues to be an issue in
Flea Beetle	Most all brassica crops	Flea beetle pressure is rebounding in a major way in many brassicas.
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage moths are inflicting damage, but most of the damage seems to be tolerable.
Leek moth	Garlic	We are yet to see any new adults in traps. Last season we did see a third flight that affected leeks in some regions. We’ll keep monitoring to help predict if this will happen again.
Mexican bean beetle	beans	We’re seeing extensive damage in Burlington, but have not heard much from other regions.
Japanese Beetle	Potatoes, Beans, Basil, etc.	Generally, we’re seeing fewer scarab beetle issues in various plantings.
Potato Leafhoppers	Beans and Potatoes	Hopper burn is being found in beans and potatoes. Undeniably, beans are being the worst hit.
Striped Cucumber Beetle	Squash/Cucumber	Thus far, on farms that we are scouting, SCB populations seem to be more manageable this season.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	We are not seeing any expanding damage from leaf miners.
Squash bugs	Summer and Winter Squash	Squash bugs seem to be significantly down from last year’s seemingly record year. In general we have seen lower levels than years past.
Squash vine borer	Winter squash	Moths are being found in traps from around the region but they are falling.
Swede Midge	Brassicas	We are seeing increasing Swede midge damage in the most susceptible crops
Tarnished plant bug	Strawberries	We continue to see high pressure from TPB

Hi all,

 

With the mini-heatwave over the weekend a few insect pests have spiked in the area. Most of these insects have been causing some damage but have really hit their stride over the last week. The ones that have been most notable on the farms over the last week have been onion thrips, flea beetles (in eggplant) and Mexican bean beetles. We’ve discussed both of these pests in detail over the past couple of weeks. If you would like to refresh your memory on the life cycles or potential management tactics, just click on the hyperlinked names above for these pests or scroll through our website blog to reread the previous entries.

 

This week, we are focusing on several of the diseases that we are seeing in abundance on farms and have been reported to UVM’s Diagnostic Clinic.

From Ann Hazelrigg:

 

“Powdery mildew is on the rise in cucurbits. Fusarium crown rot at the base of stems was identified in high tunnel cukes where soil conditions were warm and wet. I also have seen this fungus cause a rapid collapse of squash in fields in hot mid to late summer following rain. The pathogen causes a rot right at the soil line even though roots may look fine.  It can be hit or miss in fields.

 

I have seen more angular leaf spot in cucurbits this year than in years past. It is a bacterial disease that typically shows up earlier in the season because it is seedborne. Cucumbers seem to get a lot of leafspot problems and are hard to diagnose from just a picture. It is best to send in a sample if you want to know, because the pathogen can only be identified by looking for fungal fruiting bodies or bacteria under the microscope. Here is a good factsheet on leafspots from UMASS: Leaf Spot Fact Sheet

 

Bacterial wilt was diagnosed on yellow squash where cucumber beetle numbers were high earlier in the summer. Tomatoes are just showing the usual leafspot diseases with an isolated (hopefully!) incidence of late blight in Ontario. There is a fair amount of blossom end rot on some of the first ripe tomatoes. I have been hearing of blossom drop in high tunnels due to the recent high temperatures. Peppers are also showing blossom end rot on sides of the fruit. It is hard to tell the difference between BER and sunscald, but either way, the fruit is ruined!

 

Downy mildew is prevalent on some onions. This fungus-like organism will not infect the bulbs but can influence size if the plants die early. It shows up as lighter green patches on the foliage with purple-grey downy growth visible especially when conditions are moist or in the early morning. Cercospora and other leafspots are showing up on beets. Don’t forget that thrips and spider mites may explode in this hot dry weather.”

 

Also, in regards to late blight, Meg McGrath from Cornell Cooperative Extension wanted to be sure that growers in the region are aware of some late blight look-a-likes. “There are 2 other Phytophthoras that can cause leaf and sometimes stem spots that resemble late blight.: P capsici = Phytophthora blight (tomato) and P nicotianae (both hosts but more common on potato).  They don’t occur very often.  Key difference – these 2 don’t sporulate on these tissues like the late blight pathogen (won’t see the typical late blight fuzz when leaves are incubated in a plastic bag for a day), so they don’t move as easily, and they are not so destructive.  I’ve got photos in my Photo Gallery: https://blogs.cornell.edu/livegpath/gallery/”

If you have any questions regarding diseases on your farm you can send Ann a picture of a problem first and then she can follow up if a sample is needed at ann.hazelrigg@uvm.edu

 

In addition, our research team is looking to collect wireworms from agricultural soils to assess some biological controls that we have been testing. If you have any fields with a history of high wireworm pressure, we’d love to come out to your farm and put out some traps to collect for our experiments. Please reach out, we’re happy to take them off your hands…err…farm.

 

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	Adults are being found in mass right now, with a lot of late instar larvae too.
Flea Beetle	Brassica and Solanums	Flea beetles have rebounded in some areas. We’re seeing some high pressure in eggplant on some farms in Vermont.
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Damage seems to be spotty in brassicas for most of the cabbage moths
Leek moth	Onion	The second flight of leek moth has begun! Adult moths are currently laying eggs in alliums.
Mexican bean beetle	beans	We have been documenting some pretty large outbreaks in beans these days.
Japanese Beetle	Potatoes, Beans, Basil, etc.	There has been a marked increase in Japanese beetle populations in various crops.
Potato Leafhoppers	Beans and Potatoes	Hopper burn, at the moment, is limited on the farms we are monitoring. Some pressure in potatoes but not too bad.
Striped Cucumber Beetle	Squash/Cucumber	Beetles are being seen and reported in numerous cucurbit crops. The field population for winter squash have been rather normal for this time of the year, tolerable levels for most good-sized plants. However, some extensive bacterial wilt is being seen on farms with higher pressure.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	Lear miner damage has been steady in the last couple of weeks. Most of the damage seen right now is a remnant of early infestations.
Squash bugs	Summer and Winter Squash	Nymphs are being found in high numbers in most squash plantings. Adults are still laying eggs too.
Squash vine borer	Winter squash	Moths are being found in traps from around the region. We have seen many moths in traps and flying around summer squash plantings.
Swede Midge	Brassicas	We are seeing pressure building in many brassica crops. Be sure to rotate out of any fields that are showing high pressure this season. Swede midge overwinter in the field as pupae.
Tarnished plant bug	Strawberries	We are getting a lot of reports of farms with very high TPB numbers, especially flower farms.

 

 

 

 

Hi all,

With the consistent heat over the last few weeks were seeing some continued pressure from the usual (pest) suspects within the region. Luckily the dry conditions in much of the state has reduced the incidence of some of the more common diseases at this point in the season. The lack of moisture reduces the transmission and establishment of many diseases. For example, downy and powdery mildew in cucurbits seem to be mostly spotty within New England and we are not aware of any major outbreaks in Vermont.

Some notable pests and diseases from our monitoring this week:

We are hearing a lot from growers about their struggles with Colorado potato beetle. Yes indeed, it seems like a very bad year for folks with a significant amount of acreage in potato and other solanums, especially eggplant. According to some of our own research, CPB in Vermont actually shows a preference for eggplant. With the consistently high summer temperatures this season, we are seeing some extensive overlap in CPB generations leading to populations of mixed life stages (i.e. adults, larvae and eggs). Once a population becomes mixed with various generations, CPB control becomes rather problematic without some chemical intervention. In recent years, delayed planting has been as an emerging tactic for some growers in the region and is on our radar to explore more intentionally with research trials. Though it may not be helpful for this season, any growers interested in hosting delayed planting trials for CPB control (next season), please reach out. We are actively searching for farmers looking to adopt delayed planting or to establish best practices for the tactic. The more farms that participate, the easier it is to develop adaptable recommendations.

We reported last week that we have yet to see high pressure from spotted wing drosophila (SWD) this season. In fact, we were yet to find a single male fly in our traps. That luck is beginning to change as we are now seeing flies in our traps. Though the numbers are small at the moment, be aware that once you begin to find adult flies in traps, it is a good bet that your fruit has larvae feeding in them. We suspect that over the next few weeks SWD counts will be creeping up. This is bit later than last couple of years, so our hope is that this may lead to a lower peak population on some farms.

There has been a recent report of late blight symptoms on tomatoes in Canada within eastern Ontario. Despite this concerning news, the silver lining is that the outbreak is likely an isolated case and not an indication that the disease has arrived from a recent weather event. No other areas adjacent to the outbreak region have reported seeing any symptoms or validated cases. Despite this encouraging news, 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. 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.

 

As always you can find more details on individual pests and diseases from our on-farm monitoring at our pest and scouting website.

 

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	Pressure has increased in recent weeks with overlapping generations
Flea Beetle	Most all brassica crops	Flea beetles are rebounding and pressure is picking up and may effect newly planted brassicas
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage worms in general are becoming problematic in several brassica crops, especially in high tunnels where parasitism and predation may be minimal.
Leek moth	Garlic	The second flight is over in the region. Larvae are feeding on onions and leeks. We are even beginning to see pupae in some alliums.
Japanese Beetle	Potatoes, Beans, Basil, etc.	In general, scarab beetles are a real problem right now. Japanese beetles, Asiatic Beetles, and Oriental beetles can all be a big problem for flower growers this time of year. We are even seeing high pressure in edamame plantings.
Potato Leafhoppers	Beans and Potatoes	We are seeing some high pressure in some areas, especially after cutting of alfalfa or other cover crops.
Striped Cucumber Beetle	Squash/Cucumber	SCB do not seem to be that bad this year. Despite some early season outbreaks, the SCB populations seem to be rather manageable.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	A few growers have indicated that they are seeing increased damage from leaf miner. We haven’t seen much in our scouting that isn’t a remnant of the early outbreaks.
Squash bugs	Summer and Winter Squash	We’re seeing a plethora of adults and eggs with summer and winter squash. Most of the egg laying is being seen in summer squash. Nymphs are yet to be seen in any significant numbers.
Squash vine borer	Winter squash	Vine borers are showing signs of picking up and
Swede Midge	Brassicas	Swede midge damage, though spotty on the farms we’ve been monitoring, where we are seeing it has been intense. If you have a history of swede midge be on the look out.
Tarnished plant bug	Flowers	TPB is becoming a real problem in some crops. They are especially showing high pressure in flower crops.

 

 

Hi all,

With the hottest days of the summer upon us and the plethora of maturing crops within the landscape, we are well positioned to identify the dominant trends for the rest of the season. You may often hear growers say that it is a “bad year” for a particular pest. These periodic outbreaks are typically the result of many factors that may be years in the making, or at the very least, a year in the making.  This makes it difficult to predict an outbreak and sometimes hard to explain, even in hindsight. Some of the emerging “bad year” pests for 2022, include:, Japanese Beetle, Colorado Potato Beetle, Swede Midge, and onion thrips. Though the recent onion thrips outbreak around the state and region can be attributed to the hot/dry conditions that many growers are experiencing.

In honor of this unpredictability, we’d like to discuss a couple pests and diseases that have acted a bit unpredictable this season.

We’ve mentioned Basil Downy Mildew several times in the last few weeks, as the arrival of the disease within the region was quite a bit earlier this season and we were worried that it would cause early losses. However, despite its early arrival, BDM outbreaks have yet to be reported within Vermont. The limited spread of BDM is likely due to the hot and dry conditions over the past few weeks or perhaps a lack of reporting. That said, it is still important to stay vigilant and report any potential outbreaks.

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 within Chittenden County has been quiet, as we have seen very limited numbers of SWD within our traps. These numbers echo what several other extension professionals are seeing within other parts of New England. With blueberry season taking off, we expect to see increasing SWD trap counts over the next couple of weeks. We will keep you posted on our traps. For growers interested in trapping on their own farms, recent research from Jaime Piñero at UMass has shown that a simple diluted concord grape juice + salt mixture works better than many commercial traps. His research on comparisons of the traps can be found here.  The basic bait cocktail is: 1 part concord grape juice + 3 parts water + 2% salt by weight.

Leek moth pressure has been very low in onion plantings on all of the farms that we have been monitoring this season. In reality, we have seen leek moth pressure fall, in onions, each year in Chittenden County since we began monitoring them in 2016. Despite trap counts being relatively stable over those years, we’ve documented less and less damage each year. This is a bit of a different story for leeks, as we have seen significant damage in leeks, especially late in the season, since the moth’s arrival in 2014. Currently, we are seeing the end of the second flight of adult leek moths in Burlington, as many of the populations have begun their transition to the larval stage. If your onions are currently under some type of exclusion netting, you’re probably safe to begin removing those over the next week.

 

As always you can find more details on other pests and diseases at our pest and scouting website.

 

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	We are beginning to see the emergence of yet another generation of CPB adults.
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage worm damage is really picking up. We are seeing quite a bit of damage in broccoli and kale.
Leek moth	Garlic	The second flight of leek moth is coming to an end, as we are seeing fewer and fewer adult moths in our traps.
Mexican bean beetle	beans	Larvae and damage is really picking up on some farms, while others are not having a problem at all
Japanese Beetle	Potatoes, Beans, Basil, etc.	There has been a marked increase in Japanese beetle populations in various crops. This seems to be a bad year for the beetle.
Potato Leafhoppers	Beans and Potatoes	Hopper burn is being found in beans, eggplants, and potatoes. Some of the pressure is increasing and showing significant damage.
Striped Cucumber Beetle	Squash/Cucumber	SCB is being found in high numbers, but the growth of the populations seem to be slower this year, when compared to years past.  We are not seeing significant impacts on squash plants at the moment
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	The second flight of miners is well underway and we are seeing increased damage in beet greens and chard.
Squash bugs	Summer and Winter Squash	We’re beginning to see nymphs and increasing damage in summer and winter squash.
Squash vine borer	Winter squash	Moths are being found in traps from around the region. We have seen many moths in traps and flying around summer squash plantings.
Swede Midge	Brassicas	We are seeing a lot of early season damage in brassicas and that is translating into high levels of damage on farms with a history of damage.
Tarnished plant bug	Strawberries	We are seeing a high incidence of tarnished plant bugs  in the region, especially in strawberries. Cat-facing and other types of strawberry deformation from the “sting” of the bug has been seen.

 

 

 

Hi all,

This week in addition to the typical cast of [inset pest] characters, we are starting to see an increase in disease incidence across the region. The distribution of disease has been variable throughout the state, owing to the scattered nature of rain and thunderstorms this season.

Thanks to Ann Hazelrigg of the UVM Plant Diagnostic Clinic, we have quite bit of important disease notes to consider:

• As has been communicated several weeks ago, Basil Downy Mildew seems to be rather prevalent in pockets within the state. This fungal-like pathogen blows in from the south and showed up earlier than usual this year. Top of the leaves look sunburned and undersides look dirty, as if dirt has kicked up from the ground. Resistant cultivars may get the disease later, but they are not immune. Be vigilant and promptly remove any plants that you suspect may have inoculant. Once an outbreak takes hold, there is not much can be done. Also, a reminder that the Ag Pest Monitoring Site for basil is a great resource for identifying, reporting, and managing BDM.  If you suspect that you are seeing BDM, please send us a message and/or send a sample to the Plant Diagnostic Clinic here at UVM.

 

• Tomato leafspot diseases (Septoria and Alternaria) are showing up on lower leaves of field tomatoes and outer rows in high tunnels. Cultural controls (e.g staking, drip irrigation, keeping up fertility , etc.) can be effective strategies and may minimize large outbreaks, but a few key fungicide sprays may be warranted mid season to ensure later crops. Dry weather will slow the spread of the disease but with every rain, the fungi will move higher in the plant.

 

• 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 all around within the region (e.g. MA, NY, CT). This is a very early arrival for DM, in comparison to previous years.

In case you missed it, Meg McGrath of Cornell Cooperative Extension, shared the tips below for identifying CDM. Also, check out Meg’s link to biopesticide options here.

 

“Best time to scout crops for CDM is early morning (before 10).  Diagnostic is the grayish brown fuzz of the pathogen’s spores produced on the underside of the yellow, usually angular (on cucumber esp) leaf spots.  Spores are produced overnight when humid, especially when dewy, and then are released with humidity change in the am.  Growers who contacted me were looking at leaves in afternoon when the spores were gone.  When spores are not evident, put leaf upside down on damp paper towel in a closed plastic bag overnight.  If the spots are due to CDM, fuzz should be evident next morning. “

 

• There have been reports of bottom rot issues in lettuce due to wet conditions and poor air circulation. This is typically caused by rhizoctonia. Watch watering and weed pressure.

A couple important insect pest notes:

• With the recent hot dry spell, onion thrips have begun to take off on several of the farms that we have been monitoring. Typically, consistent rains help to wash the leaf tubes and knock back thrips populations. Overhead watering can mimic this effect and suppress thrips pressure. There is also some evidence that metallic mulch may delay or deter thrips from colonizing allium plantings.

 

• We are beginning to see the second flight of beet/spinach leaf miner within the region. This is a bit earlier from what we experienced the last couple of years. These leaf miners can cause significant marketable damage to chard, beet greens, and spinach. You can check crops for recent infestations, by looking on the undersides of leaves for their conspicuous white eggs. Weed control, especially for common SLM host plants like lamb’s quarter, can play a key role in reducing the likelihood of an outbreak.

As always you can find more details on other pests and diseases at our pest and scouting website.

Thanks to all of the growers that have reached out with there own questions and pest scouting information. All information and questions help us to better serve the needs of the VVBGA community.

Cheers,

Vic & Scott

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	In the upper Champlain Valley, CPB populations are transitioning to pupal stages. While in cooler regions of the state, CPB populations are largely in 3-4th instars, feeding away.
Flea Beetle	Most all brassica crops	Flea beetle pressure is largely a non-issue at this time of the season
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Status quo with cabbage moths/butterflies. We’re seeing feeding but outbreaks are mostly tolerable.
Leek moth	Garlic	Adult moths are currently laying eggs in alliums throughout the region.
Mexican bean beetle	beans	Adults are being seen in significant numbers.  We are beginning to see more eggs and some larvae. We suspect that the upcoming week we will see more larvae and damage.
Japanese Beetle	Potatoes, Beans, Basil, etc.	There has been a marked increase in Japanese beetle populations in various crops. Many farmers are reporting that this is a very intense year for JB.  It seems that, in general, we are seeing a lot of pressure from many related scarab beetles too (e.g. oriental beetle, Asiatic beetle, etc.)
Potato Leafhoppers	Beans and Potatoes	Hopper burn is being found in beans and potatoes. Undeniably, beans are being the worst hit.
Striped Cucumber Beetle	Squash/Cucumber	Thus far, on farms that we are scouting, SCB populations seem to be more manageable this season.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	The second flight of leaf miners has begun in the region. Be on the look out for their eggs on the underside of leaves.
Squash bugs	Summer and Winter Squash	We’re seeing a plethora of adults and eggs with summer and winter squash. Most of the egg laying is being seen in summer squash. Nymphs are yet to be seen in any significant numbers.
Squash vine borer	Winter squash	Moths are being found in traps from around the region. We have seen many moths in traps and flying around summer squash plantings.
Swede Midge	Brassicas	We are seeing a lot of early season damage in brassicas. It seems to be earlier than past years to see the amount of damage that we are seeing. This seems to be a consistent trend this year.
Tarnished plant bug	Strawberries	We are seeing a high incidence of tarnished plant bugs in lots of crops this season. This week several farmers have expressed high pressure in fruit crops.

 

 

 

 

 

 

Hi all,

With the middle of the season here and many people harvesting summer veggies, we’re also beginning to see some new stages of pests and the arrival of some diseases.

It is also that time of the year when you can take out that 80’s blacklight for the good of IPM! Yes, we are seeing outbreaks of tomato/tobacco hornworms throughout the region and several farmers are seeing some heavy pressure. One of the more fun ways to scout for hornworms, especially in high tunnels, is to bring out a black-light flashlight at night to spot the typically camouflaged pest on your plants. The cuticle of the hornworm will glow in response to the black-light and you can easily pick them off, as seen here. There are also some native natural enemies of hornworms, particularly the parasitoid wasp, Cotesia congregata, that can help to reduce their numbers. Being sure that there are small flowers consistently around to support the wasp population is a great way to keep the wasps active throughout the season. Research on floral resources has shown that buckwheat is a great choice for C. congregata (and for hover flies!). Wasps feeding on the nectar of buckwheat exhibit longer life spans!

Some other notable new pests and diseases:

Swede Midge seems to be a bit of a problem earlier this season than years past, particularly on the farms that we are scouting in Burlington. We were a bit surprised to find consistent and heavy pressure in cabbage, as it is typically not the most susceptible crop. Because the midge prefers to lay its eggs near the growing tip of brassicas, any of the “flower-head” brassicas (e.g. broccoli, cauliflower, etc.) are typically more vulnerable to larval feeding. Some recent UVM research has shown that even one larva can lead to marketable damage in these crops. As a result, prevention represents an important component of the IPM program for swede midge control. Insect exclusion netting can help to protect crops till flowers (broccoli, cauliflower), buds (Brussels sprouts), heads (cabbage) and/or stems (kohlrabi) can begin to develop.  Our research team is currently studying the variability of SM attractiveness in different kale varieties to explore the potential for the development of a trap crop system. You can see this research and more in our most recent research brief.

There have been several reports of Japanese beetle outbreaks on some vegetable farms. Though Japanese beetles are typically considered a pest of ornamental plants and turf grass, adults can certainly wreak havoc in some important veggie and fruit crops including basil, corn (silks), grapes, asparagus, etc. We’ve even seen some heavy pressure in solanums this year. For organic growers some possible options include neem and pyrethrin products. Also, some growers have sent us pictures of other scarab beetles (e.g. Asiatic beetle) on their farms. The control options tend to be similar for those beetles too.

We reported the presence of squash vine borer in nearby states a couple weeks ago, and now it seems that we are now seeing many SVB flying and laying eggs here in Vermont. As we previously mentioned, the primary sign of SVB is the wilting of squash plants and the presence of tunneling within the vines at the base of the plant. Unfortunately, once wilting is observed, there is very little that can be done to save the plant. Timely sprays or other applications based upon trap counts are a good protectant during flowering and one grower recently shared “as a last resort, [I] injected a mix of pyganic and organic spinosad into the holes where borers entered the crop. It worked and saved the crop. This is not preferable compared to timely sprays but something you can do if you miss spraying.”

Early blight is being reported in high tunnel tomatoes. Infections begin as small lesions, as they grow in size they exhibit a characteristic “bull’s eye” marking. Typically, early blight is sequestered and transmitted from infected plant refuse, solanaceous weeds, contaminated seeds or tubers. The fungal pathogen can then infect the leaves of new plants. Sanitation and rotation are key control tactics for reducing the likelihood of outbreaks.

Finally, we’d also like to acknowledge that all of the scouting, monitoring, data collection, and reporting behind these reports are the result of the hard work of our dedicated undergraduate research team – Gigi Walsh (UVM), Arianna Hee (UC Berkeley), Frieda Kahn (UVM), and Laurel Marshia (UVM).

As always you can find more details on other pests and diseases at our pest and scouting website.

Thanks always for your input and questions throughout the season!

Cheers,

The VEPART team

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	Currently most populations of CPB are dominated by older larvae which are about to pupate or are currently in the ground pupating. The second generation will be emerging in the next week or so.
Flea Beetle	Most all brassica crops	We continue to see flea beetle. However, because most brassicas are larger in size, the relative pressure from flea beetles is low.
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage whites are flying and laying eggs. We are seeing many larvae and some significant feeding damage in many brassicas. Diamondback moth are also being found in brassicas in both adult and larval stages.
Leek moth	Garlic	The second flight of leek moth has begun! Adult moths are currently laying eggs in alliums.
Mexican bean beetle	beans	Adults are being seen in significant numbers.  We are beginning to see more eggs and some larvae. We suspect that the upcoming week we will see more larvae and damage.
Japanese Beetle	Potatoes, Beans, Basil, etc.	There has been a marked increase in Japanese beetle populations in various crops. It seems like it might be a bad year for these pests.
Potato Leafhoppers	Beans and Potatoes	Hopper burn is being found in beans and potatoes. Though, most of the damage that we are seeing is being found in beans. Some of the pressure can be quite high.
Striped Cucumber Beetle	Squash/Cucumber	Beetles are being seen and reported in numerous cucurbit crops. Numbers are becoming substantial, and damage is significant, especially in cucumbers and C. maxima varieties of winter squash.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	A few growers have indicated that they are seeing increased damage from leaf miner. We haven’t seen much in our scouting that isn’t a remnant of the early outbreaks.
Squash bugs	Summer and Winter Squash	We’re seeing a plethora of adults and eggs with summer and winter squash. Most of the egg laying is being seen in summer squash. Nymphs are yet to be seen in any significant numbers.
Squash vine borer	Winter squash	Moths are being found in traps from around the region. We have seen many moths in traps and flying around summer squash plantings.
Swede Midge	Brassicas	We are seeing a lot of early season damage in brassicas. It seems to be earlier than past years to see the amount of damage that we are seeing.
Tarnished plant bug	Strawberries	We are stll seeing a high incidence of tarnished plant bugs  in the region, especially in strawberries and now raspberries too!

 

 

Hi all,

This week we are seeing some new insect pests that have begun to inflict damage around the state. Also, some of those pests that have been building in certain crops are now transitioning through their life stages and may be interacting differently with vulnerable crops.

The most important of the new findings for this week are:

• Leek moth are officially beginning their second “flight” of season. We are seeing modest numbers of adult moths in our baited traps. This is a clear indicator that adults are currently laying eggs on available alliums. In a week or two the LM caterpillars will begin feeding on the upper green leaves of plants. Their characteristic “window-paning” damage can be easily identified from a quick inspection. Onions tend to be relatively tolerant of LM feeding and can withstand quite a bit of damage before any yield loss is seen. However, bulb damage can sometimes occur during curing, as larvae or eggs may be brought into storage/curing areas after harvest. Topping of bulb alliums (e.g. onions, shallots, etc.) prior to curing has shown to be an effective strategy for preventing incidental larvae from contaminating storage areas.  

 

• Mexican bean beetle adults are being found in bean crops within the region. We are mostly seeing adults mating and feeding within plantings. Some egg masses are being laid, but we haven’t witnessed any extensive larval feeding…yet. The bean beetle can be easily mistaken for the lady-bird beetle, as they are closely related. So be sure that you are correctly identifying them! If they get out of hand, they can be quite a pain. The parasitic wasp, Pediobius foveolatus, is a commercially available biological control that has shown to be a relatively effective if its release is correctly timed with the larval generation. You can find more information here.

 

• Colorado potato beetle populations are being found in high numbers in most solanum crops. Many of the now pinkish and plump larvae are just about ready to begin their journey down to the soil to pupate. Once they burrow into the soil within the field, they will spend 10-14 days before emerging as adults. Any control tactics implemented before the populations shift toward their pupation stage will greatly reduce the next generation of adults.

 

• As mentioned last week, Squash bugs are actively laying eggs all over summer and winter squash leaves. Though numbers seem to be down significantly from last year, there are still quite a few egg masses being laid in the crops that we’ve been scouting. Be on the lookout for their copper eggs on the underside of leaves. Row cover can also be useful prior to flowering There are some limited chemical options available for organic growers, and similar to striped cucumber beetle, squash bugs also prefer the maxima variety of winter squash.

Thanks to all of the growers that have reached out with there own questions and pest scouting information. All information and questions help us to better serve the needs of the VVBGA community.

 

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	Most populations in the region are now a mix of large and small larvae.  But there are many 4th instar larvae ready to pupate
Flea Beetle	Most all brassica crops	We continue to see flea beetle. However, because most brassicas are larger in size, the relative pressure from flea beetles is low.
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage whites are flying and laying eggs. We are continuing to see larval feeding damage in many brassicas. Diamondback moth are also being found in brassicas in both adult and larval stages.
Leek moth	Garlic	The second flight of leek moth has begun! Adult moths are currentlty laying eggs in alliums
Mexican bean beetle	beans	Adults are being seen in significant numbers. Eggs and larvae are minimal at this point.
Potato Leafhoppers	beans and potatoes	Hopper burn is being found in beans and potatoes. It seems to be increasing in severity in many of the crops that we’ve scouted.
Striped Cucumber Beetle	Squash/Cucumber	Beetles are being seen and reported in numerous cucurbit crops. Numbers are becoming substantial and damage is significant, especially in cucumbers and C. maxima varieties of winter squash.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	Very few reports of leaf miner damage.
Squash bugs	Summer and Winter Squash	We’re seeing a plethora of adults and eggs with summer and winter squash. Nymphs are yet to be seen in any significant numbers
Squash vine borer	Winter squash	Moths are being found in traps from around the region. Moths are likely beginning to mate and lay eggs in squash plantings.
Tarnished plant bug	Strawberries	We are seeing a high incidence of tarnished plant bugs  in the region, especially in strawberries. Cat-facing and other types of strawberry deformation from the “sting” of the bug has been seen.

Hi all,

This week we are seeing exponential growth in several populations of common pests and some newly arriving pest & diseases that we should keep out eye out for in the coming weeks.

Basil Downy Mildew is being reported in the region, with confirmed occurrences in Western Mass and Rhode Island over the past week. BDM can severely affect basil plantings, and if left untended can lead to complete crop loss. The tell-tale sign of BDM is a gray coloring (from the developing spores) on the underside of basil leaves. It can sometimes look like soil has kicked up onto the bottom of the leaf.  If you suspect that it is BDM, you can place the affected leaves in a Ziploc bag with a wet paper towel to increase the sporulation. You can often be alerted to a potential outbreak by yellow coloring between the veins on the topside of leaves.

A great resource for identifying, reporting, and managing BDM is the Ag Pest Monitoring Site for basil. In recent years, some resistant cultivars have been developed. These cultivars and information on them may be found on the monitoring site too.  For those dealing with a current outbreak, prompt removal of affected plants will help to reduce the inoculum from infecting other plants. If you suspect that you are seeing BDM, please send us a message and/or send a sample to the Plant Diagnostic Clinic here at UVM.

Other important notes:

Thanks to the some of the recent larger storms in the regions, Fall Armyworm are being found in states just south of us (e.g. NY and CT.) Currently, numbers are low both in CT and NY, but it is likely that adult FAW moths will begin to move into our region soon.

Squash vine borer are being seen in traps being monitored in NH, CT, and MA. Though the current numbers being reported are low, as the next few weeks heat up, those numbers will certainly tick up.  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. Unfortunately, once wilting is observed, there is very little that can be done to save the plant.  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.

Colorado potato beetle populations are exploding in potato plantings around the state. Here in Burlington we are seeing mix of small and large larvae within potato fields. This is prime time to apply any above-ground tactics to reduce the current population size. That window may close as the larger larvae begin to head down to the soil to pupate. Larger larvae tend to become pink or salmon colored just before they crawl down the plant to burrow into the soil to pupate. However, there is some evidence that entomopathogenic nematodes may be a useful tool (as a soil drench) for reducing the in-field populations during the pupation stage/process.

Squash bug adults and eggs are being found in increasing numbers throughout Vermont. Check on the underside of leaves for their meticulously placed golden brown eggs. Straw or hay mulch can exacerbate squash bug outbreaks, as they tend to provide the perfect habitat for the pest during the hot and dry times of the day. Row cover can also be useful prior to flowering. Like cucumber beetle, squash bugs tend to prefer maxima species of winter squash.

As always you can find more details on other pests and diseases at our pest and scouting website.

 

Cheers,

Vic

 

 

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	Most populations in the region are now a mix of large and small larvae.  Soon the larger larvae will begin their journey down the plant to pupate.
Flea Beetle	Most all brassica crops	We continue to see large populations of flea beetle. We are especially seeing sustained populations in cooler regions of the state in the Connecticut River Valley.
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage whites are flying and laying eggs. We are now seeing larvae feeding damage in many brassicas. Diamondback moth are also being found in brassicas in both adult and larval stages.
Leek moth	Garlic	We are still not seeing adult moths in traps yet, suggesting that the second and generally most damaging flight has yet to occur. We’re primarily seeing larval damage and pupae in the upper canopy of allium plantings.
Potato Leafhoppers	Alfalfa	We have official reports of PLH in beans within Vermont. They will likely persist and cause harm in other crops as the season progresses.
Striped Cucumber Beetle	Squash/Cucumber	Beetles are being seen and reported in numerous cucurbit crops. Numbers are becoming substantial and damage is significant, especially in cucumbers and C. maxima varieties of winter squash.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	Very few reports of leaf miner damage.
Squash bugs	Summer and Winter Squash	We’re seeing a plethora of adults and eggs with summer and winter squash. Nymphs are yet to be seen in any significant numbers
Squash vine borer	Winter squash	Moths are being found in traps from around the region. Moths are likely beginning to mate and lay eggs in squash plantings.
Tarnished plant bug	Strawberries	We are seeing a high incidence of tarnished plant bugs  in the region, especially in strawberries. Cat-facing and other types of strawberry deformation from the “sting” of the bug has been seen.

Hi all,

This week we are primarily seeing the transition of pest populations as they move into new life stages or begin to build toward

The most important of the new findings are reltated to potatoes:

• Potato Leafhoppers have been officially identified within Vermont. The two incidents are related to beans, though PLH does have an extensive host range including soybeans, potatoes, alfalfa, etc.
• Colorado potato beetles eggs have been hatching in all of the potato plantings that we’ve been monitoring. Most populations are in the early stages (1^st and 2^nd instars) of their larval development. With the warm and dry temperatures that we’ve been seeing, the impact of those little red larvae can be significant and will only increase in severity as the season progresses. Generally, the early larval stage is most susceptible to chemical controls.

Some other important notes:

Diamondback Moths and Imported Cabbage worms are being seen in various brassica crops. Larval numbers are minimal from our scouting but that may not be the case everywhere. Check on the underside of leaves and rib-lines of brassica leaves for the green camouflaged larvae. The adults of ICW are also known as “Cabbage Whites”, as they are day-flying white butterflies. Diamondback moths are small moths, one of the smallest moth pests of brassicas, that flutter up from the canopy when disturbed.  

Striped cucumber beetles are in full force in most squash and cucumber plantings. We are seeing lots of mating pairs and feeding damage, especially in winter squash of the maxima species (e.g. Blue Hubbard).  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. Cucurbita maxima is known to be the preferred species of winter squash for cucumber beetles (and squash bugs) and is often utilized as a trap crop for other less preferred species (C. pepo and C. moschata). C. maxima has been well researched as a potential trap crop. Information the specifics of the trap-crop systems may be found here.

Thanks to all of the growers that have reached out with there own questions and pest scouting information. All information and questions help us to better serve the needs of the VVBGA community.

 

 

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	Most populations in the region are now in the early stages of larval development. This is both the most damaging stage for the crop, as the larvae can feed extensively and the most susceptible stage for the beetle to chemical controls.
Flea Beetle	Most all brassica crops	We continue to see large populations of flea beetle. We are especially seeing sustained populations in cooler regions of the state in the Connecticut River Valley.
Imported cabbage worms Diamondback moth	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage whites are flying and laying eggs. We are now seeing larvae. Diamondback moth are also being found in brassicas in both adult and larval stages.
Leek moth	Garlic	Larvae are being found in modest numbers feeding on scapes in hard neck garlic and many of those larvae are currently transitioning to pupae. We expect that the next flight will be very soon.
Potato Leafhoppers	Alfalfa	We have official reports of PLH in beans within Vermont. They will likely persist and cause harm in other crops as the season progresses.
Striped Cucumber Beetle	Squash/Cucumber	Beetles are being seen and reported in numerous cucurbit crops. Numbers are becoming substantial and damage is significant, especially in cucumbers and C. maxima varieties of winter squash.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	We continue to see leaf mining, but eggs are few and far between. It looks like the most recent generation is mostly in the larval mining stage or pupating in the soil.
Tarnished plant bug	Strawberries	We are seeing a high incidence of tarnished plant bugs  in the region, especially in strawberries. Cat-facing and other types of strawberry deformation from the “sting” of the bug has been seen.

Hi all,

The past week of scouting and monitoring has revealed much of the same from the prior week. No new pests but increasing numbers and pressure from resident pests.

There have been several reports of fusarium in garlic. Fusarium can often be the result of a secondary infection from wounds being inflicted by other culprits such as mites or insects. So be on the lookout for signs of primary pests by checking any of the infected plants for potential initial sources of damage.  This may give you some important information for managing the problem going forward.

Speaking of alliums, as garlic scapes are beginning to emerge in hardneck garlic, leek moth larvae are being found in modest numbers feeding upon or near those aromatic scapes. Leek moth larvae are known to preferentially feed upon garlic scapes and since populations are in the larval stage for most of the region, it is no surprise that we are seeing scape damage. If you value your scapes, it might be advisable to harvest them sooner than later.  We anticipate that with warmer temperatures on the horizon, we’ll see extensive feeding and a fast transition from larvae to pupae in the next couple of weeks.

Some other important notes:

Cucumber beetle populations continue to build in the Vermont, especially in the warmer areas in southern VT and close to Lake Champlain.  As mentioned last week, weed management and row cover can be effective strategies for reducing the impact on vulnerable transplants.

Colorado potato beetles are being seen in increasing numbers, but at our two monitoring sites we’re still only seeing adults and eggs. We presume that some of those eggs will soon be hatching and unleashing those voracious larvae. So be sure to be checking under leaves to see if eggs are beginning to hatch. The larval stage of the beetle is both the most damaging and susceptible stage of the beetle, especially for chemical control.  

Spinach leaf miner damage is also being reported in much of the region. Damage can be quite severe in beets and chard. Once the larvae find their way into the leaf, control options can be limited.  The characteristic small white eggs can be easily seen on the underside of leaves.  There is some anecdotal evidence that the eggs are permeable to some chemical controls, but that remains untested. Preventive sprays before the eggs hatch can be useful if timed correctly. For organic growers, it is recommended to use spinosad based products (i.e. Entrust) with an added spreader-sticker to increase the potential of contact or feeding from larvae after hatching.

Finally, thank you to farmers that reached out regarding potential potato leafhopper sitings. As of now, we do not have a validated occurrence of PLH in Vermont. If you do think you are seeing PLH, please send along any pics or information you may have to Scott or me. We are in the process of setting up a submission form on our website for sharing details or questions like these, but in the meantime, just send any pest questions directly to our email addresses slewins@uvm.edu or vizzo@uvm.edu

 

 

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	Still are not seeing any larvae but they are soon to be hatching. Be vigilant if you are planning any control measures.
Flea Beetle	Most all brassica crops	We continue to see large populations of flea beetle. We are especially seeing sustained populations in cooler regions of the state in the Connecticut River Valley.
Imported cabbage worms	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage whites are flying and laying eggs. We still have not seen larvae yet, but that should only be a matter of time.
Leek moth	Garlic	Larvae are being found in modest numbers feeding on scapes in hard neck garlic.
Potato Leafhoppers	Alfalfa	Reports of hoppers from NY growers indicate that hopper are being found in alfalfa. Maine has reported PLH in some crops too. We are yet to see them or hear about them in VT.  Be on the lookout.
Striped Cucumber Beetle	Squash/Cucumber	Beetles are being seen and reported in numerous cucurbit crops. Numbers are building in the field but the damage is not yet causing too much damage.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	We continue to see and hear of leaf mining and eggs from various Vermont farmers.
Tarnished plant bug	Strawberries	We are seeing a high incidence of tarnished plant bugs  in the region, especially in strawberries. Cat-facing and other types of strawberry deformation from the “sting” of the bug has been seen.