Hi all,
We’re back…
With UVM graduation behind us, our scouting and monitoring team is out setting up traps and scouting the crops that are out on our scouting farms. This season, we’re focusing on farms across three counties (Chittenden, Addison, and Washington) to give us a more representative sample of the region. This scouting and monitoring will again be supported by our soon arriving summer fellowship students. Without their support, we wouldn’t be able to provide these weekly reports.
Also, there are a few updates related to our webpage. First, we have officially dropped the E in VEPART, as we do more than entomology! You can now access our website via this link: https://go.uvm.edu/vpart. Also, in an attempt to improve communication with our team, we have added a couple of web forms on our webpage that will allow growers to directly submit any pest sightings or questions to our team. Direct emails from the VVBGA listserve are acceptable as well. As always, you can access our pest reports on our website or by directly navigating to the scouting blog.
Week in review
Ok, now on to the pests…Given the consistent cooler temps and wet conditions, our pest season has been relatively slow in comparison to last year. But some pests do tend to thrive in cooler spring conditions and their pressure can persist longer, as we are likely seeing this season.
Root maggots (e.g. cabbage maggot, seed corn maggot, etc.) are one of the suites of pests that do well under cooler conditions and seem to be thriving this spring. Once the overwintering generation emerges, these flies begin laying eggs at the base of their preferred crop hosts. According to NEWA’s degree day models, overwintering populations (in most areas of the state) of cabbage maggot flies have reached roughly ~75-80% emergence in most areas of the state. Adult females are actively laying eggs at the base of brassica crops. With cool temps sticking around, this pressure is likely to continue. If possible, cover your smaller seedlings with row cover or insect exclusion netting, this can make a big difference in reducing impact.
Flea beetles: Flea beetles are making their way into brassica crops here in Burlington and across the southern part of the state. Similar to root maggot flies, row covers for small seedlings can be an effective strategy for reducing their impact on the sensitive plants.
Spinach/beet leafminer: We haven’t seen or heard of any outbreaks in Vermont yet, but reports of damage are coming in from the Hudson Valley. As with most leafminers, timely or pre-emptive action is key. Insect exclusion netting is a very effective method if applied before they arrive. The bright white leafminer eggs are relatively easy to spot on the undersides of spinach and chard leaves. Once the larvae get into the leaf they are very well protected from any control strategies. If you are seeing foliar damage, remove and destroy leaves showing active “mines” to reduce future pressure. Be sure to reduce any weeds, particularly lambsquarters, that might act as an alternative host for the pest.
Leek moth: Adults from the overwintering population are no longer showing up in most of our baited traps. Eggs are likely developing on alliums, but so far, we haven’t seen larvae or feeding damage in garlic or recently transplanted onions. Just a heads-up, leek moth larvae love garlic scapes. If scapes are important for your farm, be sure to keep an eye on these updates as we approach scaping 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, using our new submission form and/or directly emailing me at vizzo@uvm.edu
| Pest | Crop | Observations |
| Cabbage root maggot: | Brassicas | We are seeing damage in various early season brassicas including radishes. |
| 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. |
| Flea Beetle | Arugula, kale, broccoli | Beetles are being found in high numbers in many brassica crops. Row covers can be an effective strategy for protecting vulnerable brassica seedlings. |
| Spinach leaf miner | Spinach | Primarily being seen in tunnels in the Hudson Valley, though we presume that they will soon be active in fields in Vermont. |