Leafroller Biofixes and Pear Psylla Hatch
Posted: May 29, 2012
Tufted Apple Budmoth and Obliquebanded Leafroller Update
At the Penn State FREC in Biglerville orchards, the 2012 biofix for the first brood of tufted apple bud moth (TABM) was established on April 20 while for obliquebanded leafroller (OBLR) the biofix was on May 19. Biofixes for both species were about two weeks ahead of the 2011 season. Based on the egg hatch models (SkyBit, Inc) for TABM we should observe 10 percent egg hatch around May 29, while for OBLR around June 3. In the majority of Pennsylvania orchards where leafrollers are present, TABM is the dominant leafroller species responsible for most of the fruit injury. If Altacor, Belt, Delegate, Tourismo, Voliam Flexi or Xpress, Intrepid or Rimon are to be used for TABM control, 1 to 2 complete, precisely timed applications of those products per brood are recommended. Use of Altacor, Belt, Delegate, Tourismo and Voliam Flexi by mid June or later (i.e., second codling moth [CM] control timing) should provide excellent control of both leafroller species as well as CM. If applying two complete sprays dedicated only against TABM, the first application should be applied at about 10 to 30 percent egg hatch (500-600 DD base 45) followed by a second application (if necessary) at about 60 to 70 percent egg hatch (800-850 DD). The low rate of Intrepid (8-10 oz/acre) should provide excellent control of TABM larvae but this low rate of Intrepid will not control CM or Oriental fruit moth (OFM). If applying only one complete application of the above mentioned compounds against TABM, this spray can be made at 30 to 40 percent egg hatch (640-695 DD).
Insecticides that are effective against TABM should also provide good control of OBLR larvae, but at least one additional application of an effective insecticide could possibly be necessary to control this pest in orchards with a history of OBLR infestation. Two sprays are usually needed for high populations of OBLR. Since the young OBLR larvae prefer to feed inside the growing terminals, the insecticide coverage of fresh growth plays a critical role in the control of OBLR larvae. Only complete sprays are recommended against this pest. The better the coverage, the better the level of larval control that will be achieved. The insecticides recommended for the control of OBLR during this time of the season include: Altacor, Bacillus thuringiensis products, Belt, Delegate, Intrepid, Tourismo, Voliam Flexi or Rimon.
Pear Psylla Control
A critical time to control the second generation of pear psylla is during the first week of hatch of the young nymphs and then a repeat application should be made 12 to 14 days later. An action threshold of 1 nymph per leaf is recommended. If chemical control is required, Admire Pro (7 fl oz per acre), Actara 25WP (4.5-5.5 oz/acre), Assail 30SG (5-8 oz plus a quart of summer oil) or Calypso 4F (4.0-8.0 oz) are very effective for psylla control. In addition, Nexter 75WP(at 8.8 oz per acre) or Portal (at 32 fl oz/acre) should provide good to excellent control of pear psylla and excellent control of European red mites. A good coverage of Surround also could help to control pear psylla although the product residues on fruit may create potential marketing issues.
Weekly Insect Bytes Now Posted at Penn State FREC Website
As during previous years, the Penn State Fruit Research and Extension Center website is providing information related to seasonal observations on insects and diseases. You will find trap data from Penn State FREC orchards and insect developmental models. The weekly Insect Bytes provide short updates on current events and happenings related to the management of insect fruit pests.