Details of use of grape root borer mating disruption

Hello, everyone, A question was asked about dates of availability for the Section 18 label for Isomate GRB-Z. I wrote earlier that mating disruption is back for this species. A little more detail is needed. A Section 18 label (an emergency registration) is valid only for the current season. It will have to be requested again each year until a full, Section 3, label is in place. In fact, the label lists specific, more restrictive dates. Effective dates of use are June 1 - July 30, with unused material (unopened containers) to be returned to the distributor by September 30. I expect that a request for a new Section 18 label will be made for next season, if a full label has not yet been approved. But in the meantime, we must abide by the label restrictions. More later, Doug

Grape curculio and "flying ticks"

Hello, everyone, Recently I've received questions about a weevil that looks suspiciously like grape curculio. First, a few words about the grape pest. Grape curculio is a reddish brown to black weevil which overwinters in the ground cover and leaf litter. Adults become active about the time of grape bloom. Adults feed on leaf tissue for about 2 weeks, and then females cut holes in young berries and insert an egg. Larvae are pale, legless, with a brown head capsule. The larvae feed within berries for about 3 weeks. When ready to pupate, larvae drop to the soil. The pupal stage lasts 3-4 weeks. Emerged adults feed on foliage until overwintering. The insect in question now, the cause of questions, is superficially similar - almost black in color, between 2-3 mm in length, with an almost round outline in dorsal view. This species, however, is the yellow poplar weevil, also know as tulip poplar weevil, or sassafras weevil. Adults of this species also emerge from leaf litter in the spring, and mate during May to early June. Eggs are inserted into the midribs of yellow poplar (tulip poplar), sassafras and magnolia - all common plants in our area. The larvae are leafminers, and the pupal stage in passed within mines. Adults emerge in mid to late June. These new adultos are active for much of the season before entering overwintering quarters. As I mentioned these are superficially similar in appearance. The adults of yellow poplar weevil are marked by striations or grooves on the elytra (wing covers). The prothorax - the section between the head and wings - is relatively small. Becuase of its size and round shape, the species is sometimes and incorrectly called "flying ticks" by the public. Weevils are entirely plant feeding! Two views of yellow poplar weevil follow:

In contrast, the dorsal surface of grape curculio is marked by several broad bumps, giving a more robust appearance. The prothorax is larger, relative to that of the yellow poplar weevil. These differene are best viewed with some good magnification.

The yellow poplar weevils, though numerous at times, are of no concern in the vineyard. More later, Doug

Grape Root Borer Mating Disruption is Back

Hello, everyone, Grape root borer is a clearwing moth native to the southeastern US, the larvae of which feed on grape roots, each larva feeding for two years. Adults appear in late June, and resemble paper wasps. This pest can be extrememly destructive, making blocks unproductive, often killing vines. More information on GRB is posted here. As many of you know, mating disruption has been the most effective management tool for grape root borer since it first received and EPA label in 2011. The commercial product, Isomate GRB, became unavailable for the 2024 season. When it became apparent that a replacement label would not be available for an extended time, we worked on an effort to apply for a Section 18 emergency registration. Thanks to combined efforts of many, the label was approved in time for the 2025 season. I am creating links relating to the new product, Isomate GRB Z, here to the approved Section 18 Label for Virginia, a press release, and a press release, and a fact sheet. More later. Doug P.

2025 Fruit Pest Management Recommendations Posted

Hello, everyone,

This year's revisions to our fruit pest management guides are now available.

The guides are available for free in PDF form. Hard copies may be purchased.

2025 Spray Bulletin for Commercial Tree Fruit Growers Click here for PDF.

2025 Pest Management Guides
2025 Commercial Horticultural and Forest Crops (including Commercial Small Fruit, Commercial Vineyards, Commercial Hops) Click here for pdf.
2025 Home Grounds and Animals (including HomeFruit). Click here for pdf.
2024 Field Crops Click here for pdf.

More later,
Doug

2025 Orchard Fruit Schools

Hello, everyone,

Next week, we will be holding our annual orchard fruit schools, Monday through Thursday. Details are provided below:

Mon, Feb 10, 8:30 AM - The Winchester Fruit School, Alson H. Smith AREC, Winchester (contact Mark Sutphin, mark.sutphin@vt.edu). Tues, Feb 11, 8:30 AM - The Rappahannock-Madison Fruit School, Graves Mountain Lodge, Syria (contact Kenner Love, klove@vt.edu). Wed, Feb 12, 8:30 AM - The Nelson-Albemarle (Central Virginia) Fruit School, Nelson Center, 8445 Thomas Nelson Highway, Lovingston (contact Kim Bryant, kimeb5990@vt.edu). Thur, Feb 13, 8:15 AM - Carroll-Patrick Fruit School, Lambsburg Community Center, Lambsburg (contact Ashley Edwards, aledwards@vt.edu).

Topics will include reflections on 7 years of horticulture research, emerging insect issues, fire blight management, management of scale insects, legal and spray guide updates, and other topics.

See you at one of the schools!

Doug

Spotted lanternfly adult activity update

Hello, everyone, Spotted lanternfly (SLF) development is about 2 weeks earlier than last year. INn 2023, first adults were seen on July 12, and in the grape-growing region of northern Virginia in 2024, June 29 (actually earlier farther east, June 12 in Richmond). Some vineyard high populations of fourth instars on Ailanthus trunks surrounding the vineyard. As adults appear in numbers, there will be immigration into vineyard blocks. There is a provisional action threshold of 5-10 adults given in the Pest Management Guide. This is likely to be conservative; unfortunately a multi-state proposal to provide a research-based action threshold was not funded this year.

A question has been asked of the advisability of removing tree of heaven (TOH) to help manage SLF. SLF is able to complete development in the absence of TOH, but does much better in its presence. It may be helpful to eliminate TOH from vineyard surroundings. However, in areas where SLF has been developing on TOH, this may not be the best time to remove those hosts, since it may hasten the movement of adult SLF into vineyard blocks.

Please let me know of any SLF-related questions.

Doug

2024 Fruit Pest Management Recommendations Posterd

Hello, everyone,

This year's revisions to our fruit pest management guides are now available.

The guides are available for free in PDF form. Hard copies may be purchased.

2024 Spray Bulletin for Commercial Tree Fruit Growers Click here for PDF.

2024 Pest Management Guides
2024 Commercial Horticultural and Forest Crops (including Commercial Small Fruit, Commercial Vineyards, Commercial Hops) Click here for pdf.
2024 Home Grounds and Animals (including HomeFruit). Click here for pdf.
2024 Field Crops Click here for pdf.

More later,
Doug