April 12 , 2004 Volume 13 No. 4 Update on Pest Management and Crop Development
Highland: Spotted Tentiform Leafminer flight beginning
(Art Agnello , Entomology, Geneva )
We haven't exactly bolted into the warmer spring temperatures just yet, but the long-range predictions are tending to show more highs in the 50's and 60's during the next week, so we're bound to start noticing some insect activity soon that bears a certain resemblance to the goings on at spring break in Myrtle Beach . Not all of this will happen overnight of course, but just to keep you from being taken by surprise when the developmental alarm clocks go off, here's a brief checklist of some prebloom arthropod activity to consider before the season cranks up.
Mites: Oil applications should go on before we reach pink in apples or white bud in pears, and as there's not much freezing weather in the extended forecast, any calm period of sufficient duration would be a suitable spray window. Start with 1.5-2.0% at first, and reduce to 1.0-1.5% as the trees reach tight/green cluster. Also, don't forget the usefulness of this tactic in stone fruit plantings (cherry, peach and plum) with a history of ERM. In apples, Savey and Apollo can be delayed until pink, and if everything else runs away with your time and a miticide application before bloom is impossible, consider Agri-Mek at petal fall in problem blocks. Besides saving some time during the hectic prebloom period, this is also a sensible rotation program for purposes of resistance management.
Rosy Apple Aphid: In particularly susceptible varieties (Cortland, Ida Red, Golden Delicious, R.I. Greening), a material such as Lorsban or Supracide can provide effective prevention through tight cluster, and will pick up any San Jose scale at the same time. Actara is also a good prebloom fit for rosy apple aphid and other pests besides, including leafminers and early plum curculio. You'll also get some side rosy control if you're using Esteem for scale at this time.
San Jose Scale: Besides the Lorsban and Supracide noted above, delayed dormant oil applications will do a good job of reducing scale populations. If you're not treating for rosies but are concerned that SJS might be increasing in some blocks, Esteem is an insect growth regulator with good activity on scale. The label calls for it to be mixed with oil, so if you're applying oil for mites anyway, this might be a tactic to try in severe cases.
Dogwood Borer/American Plum Borer: A coarse spray of Lorsban directed at trunk burr knots between half-inch green and petal fall is effective against both species that can be a problem in dwarf plantings.
Pear Midge: The first adults generally appear when Bartletts and Clapps are in the swollen bud to tight cluster bud stage, but no successful egg-laying occurs until the flower buds are a little more developed. In pear blocks with a history of midge infestation, concentrate on those portions of the orchard most protected from the wind by trees, high ground, or buildings, as the midges tend to be most numerous in these spots. Organophosphates like Guthion are the most effective materials; 2 sprays are recommended, one between swollen bud and first separation of the sepals, and another 7 days later (or at white bud, whichever comes first).
Pear Psylla: If you're just starting on your oil sprays, one application at 2% or two at 1% until white bud should provide adequate protection against egg deposition until an insecticide spray might be elected. Esteem at white bud or after petal fall has shown good activity in suppressing psylla numbers. Agri-Mek used shortly after petal fall has given good control if applied correctly (well-timed, adequate coverage, combined with an oil adjuvant), and split applications of Nexter or Provado, also starting soon after petal fall, will keep nymph numbers down through the early summer.
Oriental Fruit Moth: The first adults could start flying during the next two weeks, depending on how much of a warming trend we get, but we don't necessarily recommend pheromone disruption against this brood in peaches or apples, as your plum curculio sprays will serve double duty against OFM as well. However, be prepared to start these at petal fall even in peaches, as shuck split will be too late to get the first egg-laying moths.
Black Cherry Aphid: In (sweet especially) cherry plantings with a history of infestation by this pest, which curls and stunts leaves, a prebloom inspection for these shiny black metallic insects can warrant an application of Thionex or a pyrethroid (Asana or Warrior).
Tarnished Plant Bug: Early season feeding by overwintered adults in peaches can damage flower buds and cause bleeding of sap from twigs and shoots. If you note several bleeding sites per tree, a pink application of a pyrethroid or Carzol can offer some control. In apricots, choose either Asana or Warrior.
PRODUCT UPDATE UPDATE
Along with the crocuses, one of the things that pops up at this time each year is the realization that we've managed to miss some recent NY product registrations in our Tree Fruit Recommends. We apologize for the oversight of omitting the following two products that have NY labels and may be of use in your tree fruit arthropod management programs:
BRIGADE 10WS (bifenthrin, FMC) - Now labeled for use on pears in NY, this is a relatively established pyrethroid in other crops, and was one of the first that demonstrated mite control in addition to the efficacy profile common to other members of this family. Besides European and twospotted spider mites, the label also includes aphids, codling moth, green fruitworm and leafrollers, leafhoppers, plant and stink bugs, and plum curculio. Please note that pear psylla is not on the label.
DELIVER 18WG (B.t.k., Certis) - Labeled on all tree fruit crops grown in NY, this B.t. product has been tested by Harvey Reissig with good results on obliquebanded leafroller. Also on the label are codling moth, green fruitworm, oriental fruit moth, and redbanded leafroller.