Insect Monitoring Especially Important this Season!

Posted: May 31, 2011

Despite a relatively slow start for 2011, the degree accumulations base 43° at the Fruit Research and Extension Center (FREC) in Biglerville as well as the Penn State Research Center in Rock Spring (Centre County) are already the second highest for the last 6 years.

First Generation Codling Moth

At the FREC this year’s biofix for codling moth (CM) occurred on May 7 and as of May 30 the CM model (SkyBit, Inc.) forecasted about 30 percent CM egg hatch. However, based on the latest observations just finished by Dr. Neelendra Joshi (Penn State), it appears that the actual dynamic of CM field populations is slightly slower and compared to the currently utilized model, this output is forecasting the egg hatch ahead of the real field occurrence. Based on these observations, the first recommended application of larvicidal insecticides to control this pest in most orchards should be happening about this time of the season (delayed to about 300-350 DD50).

The recommended, broad-spectrum larvicidal insecticides to control CM include:  Altacor, Assail, Avaunt, Belt, Calypso, Delegate, Guthion, Imidan, Tourismo and Voliam Flexi or Voliam Xpress. (Reminder: During 2011 a restriction is in place for the use of Guthion (azinphos-methyl) allowing only 3.0 lb of formulated product per entire season). A second insecticide application against CM, depending on pest pressure, is usually needed around 14 to 17 days after the first application. Unfortunately, some of the most active insecticides against CM are not the best products against BMSB and vice versa, although certain products, especially Assail or Voliam Flexi (a mixture of the same active ingredients as in Altacor and Actara) are effective against both pests. Please see the BMSB article for further information.

During the last few years we observed an extended flight of CM, sometimes lasting until the end of June. If you continue to catch significant numbers of CM adults in orchards during the mid- to latter part of June and you have already made two applications for CM, a third insecticide application may be needed during this period as well.

We can not stop emphasizing the importance of insect monitoring in each orchard, especially now with the tremendous pressure from brown marmorated stink bug.

Tutfted Apple Bud Moth/Obliquebanded Leafroller Update

The biofix for the first brood tufted apple bud moth (TABM) at the FREC in Biglerville orchards was established on May 11. 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 CM control timing) should provide excellent control of both leafroller species. If applying two complete sprays dedicated 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 codling moth or Oriental fruit moth. 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 may be necessary to control this pest in orchards with a history of OBLR infestation. Phenologically, the most effective timing for controlling OBLR larvae usually occurs about the second application of insecticides for TABM, followed by an additional application 10 to 12 days later. 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, Provado 1.6F (16 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. Nexter 75WP (at 8.8 oz per acre) or Portal (at 32 fl oz/acre) should also provide good to excellent control of pear psylla as well 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 on FREC Website

As during previous years, the Penn State FREC website will feature Weekly Insect Bytes. In addition to our weekly updates on pest captures and insect developmental models this part of our website will also provide short updates on current events and happenings related to the management of insect fruit pests.

Seasonal Activity of Fruit Pests

2011 season - weekly captures of adult moths in pheromone traps located at Penn State FREC Biglerville, PA (Adams County):
Species 4/8 4/15 4/22 4/29 5/06 5/13 5/20 5/27
Key to acronyms: RBLR - redbanded leafroller; STLM - spotted tentiform leafminer; OFM - Oriental fruit moth; CM – codling moth; TABM – tufted apple bud moth; OBLR – obliquebanded leafroller.
RBLR 5 10 15 14 5 2 0 0
STLM 21 142 218 121
29 17 1
OFM 0 9 78 258 298 515 64 174
CM - - - 0 0 26 37 86
TABM - - - 0 0 1 14 18
OBLR - - - - - 0 0 0
Degree-Day Table: Accumulated degree-days base 43° F from Jan 01 for each reported year (courtesy of SkyBit, Inc.).
Site, Date
4/21 4/28 5/05 5/12 5/19
Biglerville, 2011 323 463 563 695 814 1023
Biglerville, 2010 486 550 707 791 907 1111
Biglerville, 2009 305 439 543 664 781 971
Biglerville, 2008 355 472 552 652 746 866
Biglerville, 2007 290 396 510 645 758 942
Biglerville, 2006 447 514 625 725 823 958
Rock Spring, 2011 197 315 387 509 610 802
Rock Spring, 2010 408 462 596 656 752 933
Rock Spring, 2009 226
345 427 520 616 786
Rock Spring, 2008 240 352 421 504
573 664
Rock Spring, 2007 218 301 398 528 619 788
Rock Spring, 2006 342 398 504 590 663 767

Contact Information

Grzegorz (Greg) Krawczyk
  • Extension Tree Fruit Entomologist
Phone: 717-677-6116