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. |