Hi all,
After the warm temperatures and dry conditions that have typified the last couple of weeks, we are finally receiving some cooler and wetter conditions. Though the rains have provided us with much needed moisture, it comes with its own set of challenges, particularly related to pests and diseases.
One of the more important scouting notes this week is the arrival of potato leafhoppers (PLH) in the region. We’ve seen adult PLH on all of the farms that we’ve been currently monitoring in both Chittenden and Addison counties. This is the earliest that our team has identified PLH in Vermont (roughly 4 years). We are yet to see any nymphs, but some of the populations in potato have been pretty large, so we assume that they’ve been here for at least a week or more. We are also finding PLH adults in bean crops. So, it is a good time to start scouting for the 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, which tend to be the most damaging life stage. The sooner you can identify them, the better. Once you get “burned,” the damage is not reversible.
PLH can be a serious pest in a variety of crops including potato, beans, eggplant, alfalfa, strawberries, among many others. You will often see a spike in populations following hay-cuttings. 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 will rapidly grow soon after colonizing a crop, so be on the lookout.
A few of the most important new developments:
Unfortunately, Spotted wing drosophila adults have been identified in traps in Eastern New York and Western Massachusetts. We are yet to find any in our traps, but it seems imminent given the proximity of those areas to our trapping sites. This would also be the earliest that we’ve seen SWD in our traps since we’ve begun our scouting and monitoring program. We’ll let you know as soon as we see SWD in our traps. 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.
Leek Moth traps are still clean of adult moths, so we are still between flights in the region. Larval damage is really picking up in garlic, as we’ve seen substantial damage in on garlic scapes. We have also spotted some leek moth cocoons at the tops of garlic leaves. The second flight is likely to begin in the next week or so. As it gets closer to harvest time for some alliums (e.g garlic), it is important to scout and see what stage (i.e. larvae, pupae, etc.) of moths you have in your crop. Unsuspectingly bringing eggs and/or larvae into curing and/or storage areas can be an issue. Our research has shown that topping alliums prior to curing can reduce the risk of damage from leek moth larvae occurring during storage and does not affect the long term quality of the crop.
Striped cucumber beetles are in full force in most squash and cucumber plantings. Thanks to all of the farmers that reached out to us last week indicating that SCB has been active for a couple of weeks. 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. Kaolin clay applications (e.g. flat dunks) are a popular and effective organic method for reducing pressure on smaller seedlings.
Finally, I want to acknowledge and extend gratitude to our newest summer research scouts, Julian Wise, Maya Lis and Zack Watson-Stevens. These burgeoning entomologists will be doing the bulk of the scouting work for the rest of the season. You may see them on a farm or at a farmer’s market, in which case give them a high five! These scouting reports wouldn’t be possible without their tireless effort.
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.
Cheers,
Vic, Julian, Maya, Zack, and the rest of the VEPART team
| Pest | Crop | Observations | ||
| Colorado Potato Beetle | Potatoes | We are seeing CPB adults and eggs in eggplant and potato. Populations are predominantly adults and eggs | ||
| Spinach/Beet leaf miner | Spinach, Swiss Chard, Beets | Adult flies are flying and laying eggs. Larvae are making significant damage with their mining. It seems like a very bad season. | ||
| Striped Cucumber Beetle | Squash/Cucumber | Beetles are being seen and they are in high numbers | ||
| Flea Beetle | Broccoli/ Kale | Pressure seems relatively modest in most areas | ||
| 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 | Potato and Beans | We are seeing PLH adults in both potato and beans. We haven’t seen any nymphs yet, but adult numbers have been high in some areas. | ||
| Three-lined potato bug. | Tomatillos | We are seeing some large outbreaks in tomatillos | ||
| Leek Moth | Onions/Garlic | We are primarily seeing pupae and late instar larvae. Though our traps are still clear, so the second flight is still yet to begin | ||