VEPART Pest and Scouting Report

Hi all,

As we begin the slow roll into June, it is peak season for the emergence and arrival of many of our most concerning insect pests. Unfortunately, it seems that the early season rains combined with warming drier temperatures, has led to some early outbreaks and arrivals.

One  of the more important scouting notes this week is the arrival of potato leafhopper (PLH) populations within the northeast farming region. We have received warnings from both Maine and New York extension folks that PLHs are being seen in alfalfa and potentially other crops. PLH can be a serious pest in a variety of crops including potato, beans, eggplant, alfalfa, strawberries, among many others. Legumes tend to be their preferred host.

We have not witnessed any hoppers or the characteristic “hopper burn” symptoms in any of the crops that we are monitoring, and we have yet to hear any reports of PLH from VT farmers. Though, it is only a matter of time before we see or hear about them in Vermont.  So, it is a good time to start scouting for the adults and small green nymphs. Tapping or brushing the plants is one way to check plants for adults (they’ll jump/fly when disturbed) but you’ll need to look on the underside of leaves to find the wingless nymphs. The sooner you are able to identify them the better, as once you get “burned” the damage is not reversible.

Luckily, PLHs are not able to overwinter this far north. However, once they are found in the region, they are here to stay for the season.  PLH populations often exhibit explosive population dynamics, with rapidly growing populations soon after colonizing a crop, so be on the lookout and let us know if you see anything!

A few other important notes from the past week:

As mentioned last week, Colorado potato beetle adults are actively laying eggs in eggplant and potato plantings. We’ve even seen some colonizing field tomatoes. In the next week or so, those eggs are will start to hatch, if they haven’t already. The larval stage of the beetle is the most damaging stage, so any control tactics should be timed accordingly.

We’re seeing a lot of slug pressure in lower lying wetter areas. Slugs are particularly an issue in crops that capture and hold water within their foliage (e.g. napa cabbage, lettuces, etc.), though they can just about eat any broadleaf crop. Commercially available baits containing iron phosphate, are shown to be rather effective and with a low impact on the environment.

Striped cucumber beetle are also actively colonizing squash plantings in the area. More and more growers are using floating row covers as an early season control strategy. Once plants are large enough and flowering, the row cover can be removed for pollination. Cucumber beetle are also vectors for bacterial wilt, so any efforts to reduce their populations or feeding early in the season is beneficial for the long-term health of the crop. Because they feed on a various weeds (e.g. wild amaranth, lambsquarters, etc.), it is important to be cognizant of the weed species in and around fields and manage accordingly.

 

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	High numbers of CPB in eggplant and potato. Adults are mating and laying eggs at a precipitous rate. Eggs will be hatching soon if they haven’t already.
Spinach/Beet leaf miner	Spinach, Swiss Chard, Beets	Adult flies are flying and laying eggs. Many reports of leaf mining and eggs from various Vermont farmers.
Striped Cucumber Beetle	Squash/Cucumber	Beetles are being seen and reported in numerous cucurbit crops. Numbers are building in the field.
Flea Beetle	Broccoli/ Kale	We are in peak flea beetle season. Large populations are being reported throughout the state are continuing to be feeding and causing significant damage.
Imported cabbage worms	Brassica crops (Kale, Broccoli, Cabbage, etc.)	Cabbage whites are flying and laying eggs. We have not seen larvae yet, but that should only be a matter of time.
Tarnished plant bug	Strawberries	Tarnished plant bugs are being found in strawberries in the region. Cat-facing and other types of strawberry deformation from the “sting” of the bug has been seen.
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. They are likely here in VT, so be on the lookout.

Hi all,

This week we have officially added a new monitoring site outside of Chittenden County. The farm team at Cedar Circle Farm in Thetford, VT will be sharing their weekly observations and scouting reports with our team to better capture the distribution and movement of pests throughout the region.  We’ll incorporate their data to our weekly reports to give a more complete picture of the pest and disease issues in the state.

In general, we are starting to see things really picking up over the past week. With the consistent rains and new plantings out in many fields and gardens, pests are arriving in droves.

Some highlights from the past week at our locations are:

Colorado potato beetle adults are being found in large numbers mating and laying eggs in eggplant and early season potatoes. Be sure to check under leaves for the characteristic orange egg masses. In the next couple of weeks expect those hungry larvae to begin emerging from their eggs. Larvae are the most damaging stage of the beetle, but are also most susceptible to chemical treatments. Also, in recent years many farmers have reported success in reducing CPB damage by delaying planting.

Flea beetle infestations are being reported by many growers and gardeners. Floating row covers or insect exclusion netting for seedlings and smaller plants can be a very effective strategy for minimizing the impact of flea beetles on brassicas until plants are large enough to tolerate the pressure.

Cabbage white butterflies, the adult form of the imported cabbageworm, are actively flying in the region and laying egg on brassicas. We are yet to see larvae or their characteristic leaf feeding damage. Larvae and eggs can be found on the underside of leaves. Smaller larvae can be difficult to see, as they are green and camouflaged.

Spinach leaf miner eggs and larval tunnels have been reported by growers in NY, though we are yet to see them on plantings in Burlington. They are likely flying and laying eggs here in Vermont, however, the susceptible plants (e.g. spinach, chard, etc.) at the UVM farm are still under row cover for protection so we haven’t seen them. Their bright white eggs are easily identified on the underside of leaves, in collections of 2-10 eggs. Spinach leaf miner infestations can often be exacerbated by the presence of lamb’s quarters and wild amaranth species. So, weed management can have a significant effect on their impact.

And finally, as mentioned last week, Striped cucumber beetle are being found in high tunnels and are showing up in some field plantings of cucurbits.

As always you can find our weekly reports at go.uvm.edu/pests

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

vizzo@uvm.edu & slewins@uvm.edu

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	High numbers of CPB in eggplant and potato. Adults are mating and laying eggs at a precipitous rate.
Spinach leaf miner	Spinach, Swiss Chard, Beets	Adult flies are flying and laying eggs. Some larval tunneling is being reported in NY and a few growers in Vermont.
Striped Cucumber Beetle	Squash/Cucumber	Several farmers have reported the arrival of cucumber beetles in high tunnels. Numbers are low in any field cucurbits at the current time.
Flea Beetle	Broccoli/ Kale	We are in peak flea beetle season. Large populations are being reported throughout the state.

Hi all,

With all of the heat and rain over the past week, several of our early season pests have begun to emerge and are being found in relative abundance in fields and high tunnels in the region.

As mentioned last week, we are particularly interested in keeping an eye out for signs of the allium leaf miner, (ALM), as we would like to monitor the expansion of this new invasive pest. The adult female fly deposits eggs directly in the leaves of allium plants leaving a distinct line of white dots (egg laying scars).  ALM’s impact is seen during the early spring and can be a significant issue for growers harvesting scallions or overwintered onions. The ALM displays a summer hibernation which typically begins around the first week of June and ends around September. So it typically is not an issue for garlic and onion growers. However, the second generation emerges just in time to affect any late season alliums (e.g. leeks). 

A few other highlights from the last week:

Colorado potato beetle: Reports of emerging adult beetles are being shared throughout the region. Adult beetles will seek out both wild and cultivated solanums during this time of the season. This overwintering generation will begin mating and laying eggs over the next week, so be sure to scout under the leaves of any solanum crops (e.g. tomatoes, eggplants, etc.) that you may have out there in your fields. 

Flea beetles: Flea beetles seem to be thriving, as we’ve seen some large outbreaks in brassica plantings. Row covers for small seedlings can be an effective strategy for dampening their impact on the sensitive plants. 

Cabbage root maggot: According to the degree day models from NEWA, overwintering populations of cabbage maggot flies are roughly ~95% emerged from their overwintering habitat. Adult females are actively laying eggs at the base of brassica crops. 

Striped cucumber beetle: Beetles have arrived on some farms, especially in unscreened high tunnels. We anticipate that these populations will be growing at a rapid rate over the next few weeks. 

Our new website for the scouting reports can be found here

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 and improved New England Vegetable Management Guide. And, as always feel free to reach out to us if you have any questions.

vizzo@uvm.edu & slewins@uvm.edu

Pest	Crop	Observations
Colorado Potato Beetle	Potatoes	CPB adults are currently emerging from their overwintering habitat,  these adults are searching out their first host plants to mate and lay eggs.
Leek Moth	Onions/Garlic	Adult moths from the emerging overwintering population are no longer showing up in baited traps. Eggs are likely developing on alliums, however, we are yet to  see any larvae or feeding damage in any alliums.
Striped Cucumber Beetle	Squash/Cucumber	Several farmers have reported the arrival of cucumber beetles in high tunnels
Flea Beetle	Broccoli/ Kale	Beetles are being found in high numbers in many brassica crops. Row covers can be an effective strategy for protecting vulnerable brassica seedlings.