June 30, 2003 Volume 12 No. 16 Update on Pest Management and Crop Development
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Upcoming Pest Events |
Trap Catches | Pest Focus | Insects
Upcoming Pest Events | Trap Catches | Pest Focus | Insects
Upcoming Pest Events | Trap Catches | Pest Focus | Insects
Geneva: Spotted tentiform leafminer 2nd flight began 6/23. The first sample of sap-feeding mines should be taken at 690 degree days (base 43°F) following this event. DD43 since then = 200. Obliquebanded leafroller flight began 6/17. Sampling should take place at approx. 600 degree days (base 43°F) following this event. DD43 since then = 314 Highland: Green apple aphid and potato leafhopper nymphs increasing. Spotted tentiform leafminer 2nd flight began 6/16. DD43 since then = 377. Obliquebanded leafroller flight began 6/10 in Milton. DD43 since then = 531
Upcoming Pest Events | Trap Catches | Pest Focus | Insects
Geneva Predictions: Roundheaded Appletree Borer RAB egglaying begins: June 15. Peak egglaying period roughly: July 3 to July 17. Codling Moth Lesser Appleworm Obliquebanded Leafroller If using BT insecticide, optimum date to begin 2 to 4 weekly
low-rate applications for small OBLR larvae is roughly: July 2. Oriental Fruit Moth Redbanded Leafroller San Jose Scale Spotted Tentiform Leafminer
Highland Predictions: Roundheaded Appletree Borer Codling Moth Lesser Appleworm Obliquebanded Leafroller Oriental Fruit Moth Redbanded Leafroller San Jose Scale Spotted Tentiform Leafminer
Plum Curculio. Accumulated heat units need to reach 340 (base 50°F) from petal fall before the predicted end of the immigration of ovipositing females. All sites are well past this mark after last week's heat wave. Our numbers as of Sunday June 29:
Oriental Fruit Moth. Applications against the 1st brood should all be finished by now. According to the provisional Penn State model, the sprays against the 2nd brood aren't normally advised until we get to 1150 (peaches) and 1450 (apples) DD (base 45°F) from biofix. However, according to discussions with researchers in both PA and NJ, the highly unusual cool spring temperatures of this year have played havoc with this model, and developmental events for the 2nd brood OFM in these locations have evidently been delayed at least 150-200 DD past the predicted DD benchmarks. For example, although the 5% hatch of the 2nd brood is generally predicted at approximately 875 DD, this event was noted only last Friday in PA, with the accumulation nearing 1100 DD. Our best advice for sprays against this brood would be to wait until the first moths of the 2nd flight start being caught, and then figure on the 10% hatch to occur approximately 175-200 DD after that date. Anything applied before then will likely be too early to have much effectiveness. Our numbers as of Sunday, June 29:
Codling Moth. All sites reached the 250 DD (base 50°F) first spray date early last week (if not before), so the second spray for blocks with a specific CM problem would not be recommended until 14 days after the first application. Obliquebanded Leafroller. The predicted 1st hatch of the summer OBLR brood is about 350 DD (base 43°F) after the first moth catch, which we estimate to be June 17 in western NY, and June 16 in the Hudson Valley. As of Sunday, June 29, Geneva had 280, Albion 300, and North Appleton 298, so this event should begin sometime this week in most sites. Growers using a Bt program would be advised to make their first application in time to coincide with the beginning of hatch (see Orchard Radar Digest in this issue).
(Art Agnello & Dave Kain, Entomology, Geneva) San
Jose Scale Comstock
Mealybug The overwintered eggs hatch from mid-April through May and the nymphs (crawlers) migrate from the oviposition sites to their feeding sites on terminal growth and leaf undersides of trees and shrubs. This hatch is completed by the petal fall stage of pears. Nymphs that hatch from these overwintered eggs are active from roughly early May to early July. As the nymphs approach the adult stage, they tend to congregate on older branches at a pruning scar, a node, or at a branch base, as well as inside the calyx of pears. Second- (summer) generation nymphs are present from about mid-July to mid-September. The Comstock mealybug poses two major concerns for the pear processing industry of New York: First, the emergence of crawlers and adult females from the calyx of pears at the packinghouse creates a nuisance to workers. Second, pears to be made into puree typically are not peeled or cored by New York processors, so infestations can potentially result in unacceptable contamination of the product. Another problem, of concern to apple growers in the 1930s and 1940s, and again in the Hudson and Champlain Valleys in the early 1980s, is that the honeydew secreted by the crawlers is a substrate for sooty molds growing on the fruit surface. This type of damage has also been noted on peaches in Niagara Co. and in Ontario, Canada. These molds result in a downgrading of the fruit, and are therefore an additional cause of economic loss. To date, the Comstock mealybug has been a problem to growers of processing pears because of the contamination and aesthetic reasons noted. An infestation generally requires one or more insecticide sprays during the growing season, directed against the migrating crawlers. Examine the terminal growth for crawler activity periodically throughout the summer. Crawler and adult female activity can also be monitored by wrapping double-sided tape such as white carpet tape around low scaffold branches and inspecting for crawlers that have been caught by the tape. They can be recognized with a hand lens or, with some experience, by the unaided eye. Sometime in early August, we'll advise an application of a material such as Provado, Diazinon, or Lannate to control this insect. Dogwood
Borer Dilute trunk applications of an insecticide with good residual activity can provide control of established infestations. Lorsban 4E or 50W may now be used postbloom as a directed trunk spray in N.Y. for borer control in apples. We feel that Lorsban is the best tool we presently have for this use, and mid-July would be a good time to take advantage of this welcome opportunity to use it on apples to control both dogwood borer and the second generation of American plum borer. Another option at this point in the season is an application of Thiodan 50WP applied once during this first week of July, and again one month later at the beginning of August. We would also note that, in case you didn't follow the strategy of using Lorsban as a prebloom trunk spray for American plum borer, these treatments will also serve as the last opportunity for a control measure against this pest. Additionally, this is the time of the season when a second trunk application of a pesticide should be made against peachtree borers in cherries and peaches. A coarse spray directed at the trunk and scaffold branches gives the best protection against ovipositing adults; shutting off all but the bottom nozzles on a speed sprayer won't do an effective job. Use Lorsban 4EC, Thiodan, or a pyrethroid (Ambush, Asana, Pounce); do not spray the fruit. Peachtree
Borers Correction Last week's article on aphid control listed Avaunt as one of the spray options for this pest. When Avaunt first became available, there was a thought that it might have some activity on aphids, although they don't appear on the label. Over time, there hasn't been much field evidence to support this assumption, so in fact it should not have been included in the list of recommended materials.
This material is based upon work supported by Smith Lever funds from the Cooperative State Research, Education, and Extension Service, U.S. Department of Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to: Scaffolds
Fruit Journal Online at <http://www.nysaes.cornell.edu/ent/scaffolds/>
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