Hi all,
I hope things are going well out in the fields as the temperatures begin to really heat up over the next week or so. With high temps come faster generations and more insect outbreaks.
We have some new discoveries this past week of some important pests that are just beginning to be found on farms.
The first spotted wing drosophila (SWD) adult fly of the season was just captured in one of our traps. The good news is that it was only one fly, found in just one of the ten traps. This low level of trapping activity is similar to what’s being observed across the region, so it looks like we’re at the beginning of the SWD season. We’ll keep you posted as the season progresses. For those who want to monitor SWD directly on their own farms, we’ve had great success with the Scentry SWD lures and traps, although they can be a bit pricey. In previous years, we’ve used a diluted grape juice solution for trapping, and that seems to work well too. That said, we’ve generally seen higher trap counts and earlier detections with the Scentry lures, suggesting they may be a bit more effective. A great comparison review of different lures and traps was recently published in the UMass Fruit Notes.
Onion thrips are just starting to show up in onions on our monitoring farms. Populations are still below threshold for now, but with hot weather on the horizon, outbreaks may not be far off. Thrips can be tricky to spot if you’re not familiar with them, but once you know what to look for, they’re pretty easy to identify. We’re mostly seeing yellow-orange juveniles (nymphs) tucked into the crevices at the base of onion plants. As they mature, you’ll start to notice the darker, blackish adults moving around.
In relation to onion thrips management, our team is currently testing a variety of tractor-applied mulches to evaluate their effectiveness in several ways, including their impact on thrips populations. We’re trialing two OMRI-approved paper mulches, black and silver plastic mulches, and a textured silver plastic. We’re also collecting data on soil temperature and moisture, pest management, and basic soil health indicators. Soon, we’ll be adding a prototype manure-based paper mulch made from upcycled manure solids. If any growers are interested in trialing some of the best-performing mulches next season, please reach out to our team. We’ll provide the mulch in exchange for your opinions and feedback on the mulch you’ve selected to compare to your “typical” practice.
Leek moth outbreaks are starting to show up in scapes on select farms in the region. The distribution appears to be patchy, as some farms are getting hammered while others remain mostly clear of leek moth. That said, we’re seeing a lot of pupae (cocoons) in garlic, suggesting that the next flight will likely begin soon. We expect to start seeing adults in traps next week. In terms of management and impact, it’s important to note that we haven’t observed yield losses in garlic or onions due to leek moth, even during severe outbreaks. Most marketable damage in these crops tends to occur during curing or storage, as larvae move down into the bulb away from the drying leaves. Topping garlic and onions before curing and storage can help reduce this risk. However, for leeks and shallots, we do see more direct impacts on yield. In those cases, exclusion netting or well-timed pesticide applications, typically about seven days after peak flight, can be effective. If you have any questions about leek moth, feel free to reach out. Our team has been researching these buggers for quite a while.
One pest that’s surprising us in the region this year is the presence of tortoise beetles in tomatoes across the Northeast. Although we’ve seen them sporadically on some farms in the past, they seem to be showing up more frequently this season. From what we’re hearing, they’re turning into a bit of a nuisance across the board.
We’re not sure what combination of factors has led to this unusual tortoise beetle year, but I wanted to share this in case you’ve been seeing them too. In our experience, they’re not typically a major problem and are hopefully just transient feeders on your plants. One cool thing to look for, if you are seeing them, is the larvae using their “fecal shield” to deter predators. The larvae actually hold their own dried feces over their backs like a little umbrella to ward off would-be attackers.
Other monitoring of note from the region:
- Swede midge damage from the first generation is showing up in brassicas in northern New York.
- Potato leafhoppers have been seen in NY and NH, which likely means they are on their way to VT or already here. We’ll report on them next week, but be on the lookout.
- Leafminer mines are being seen in beet, spinach, and chard in MA. We’re still seeing mostly eggs in VT at the moment.
- Cucumber beetles are in full force around New England.