Historical biofix dates for oriental fruit moth, codling moth, and tufted apple budmoth at the Winchester AREC

“Biofix” is the calendar date on which the first sustained capture of insects emerging from the overwintering generation occurs. At the Winchester research center, we establish biofix for three key moth pests of peaches and/or apples:

  1.  oriental fruit moth
  2.  codling moth
  3.  tufted apple budmoth

Prior to the onset of moth emergence and flight each spring, traps baited with the pheromone lure for each species are deployed in research center orchards and captures are recorded daily. When one or more moths are captured in each of at least two of three traps over at least three consecutive evenings, biofix is set as the first day on which these sustained captures occurred.

Starting on the biofix date, daily heat until accumulations (“degree-days” or “DD”) are calculated based on known developmental threshold temperatures for each species. Accumulated degree-days are used with models that predict the rate of development of eggs and the hatch of larvae for each species. Critical points in the development of each generation of each species are predicted by the model, so that tree fruit growers can time their control measures optimally.

In combination, determining the biofix date and initiating degree-day models based on biofix each year enable best management practices regardless of the potentially large annual variations in the environmental conditions that affect pest emergence and developmental rate. The accompanying table illustrates the annual variations in biofix dates for oriental fruit moth, codling moth, and tufted apple budmoth at the Winchester research center since 2000.

Year Oriental Fruit Moth Codling Moth Tufted Apple Budmoth
2000 April 1 April 29 April 29
2001 April 7 April 30 May 4
2002 March 30 April 27 May 5
2003 April 14 May 3 May 12
2004 April 16 April 30 May 6
2005 April 11 May 8 May 8
2006 April 7 April 23 May 1
2007 April 20 April 30 May 10
2008 April 10 April 25 May 6
2009 April 17 May 2 May 20
2010 April 5 April 29 May 13
2011 April 18 April 26 May 9
2012 March 20 April 14 April 29
2013 April 11 May 2 May 16
2014 April 12 May 8 May 12
2015 April 18 May 4 May 16
2016 April 11 April 25 May 2
2017 April 3 April 21 April 29
2018 April 22 May 3 Not available

 

Section 18 for Venom and Scorpion against brown marmorated stink approved for Virginia

Greetings,

On June 13, 2018 the EPA approved a Section 18 Emergency Exemption for use of the neonicotinoid insecticide, dinotefuran, against brown marmorated stink bug in pome and stone fruit crops in Virginia. Growers from the other States that have previously participated in this Section 18 should contact their State Department of Agriculture regarding the status of this petition. The two products included in this exemption are Venom Insecticide and Scorpion 35SL Insecticide. Per application, Venom can be used at rates between 4.0 and 6.75 oz of product per acre (0.179 to 0.302 lb active ingredient) and Scorpion at 8.0 to 12.0 fl oz of product per acre (0.203 to 0.304 lb active ingredient). Restrictions include a maximum of two applications per season, a seasonal maximum of 0.608 lb active ingredient per acre (regardless of product used), and a minimum 7-day re-application interval. The re-entry interval for both products is 12-hours and a 3-day pre-harvest interval must be observed for both. This compound is highly toxic to bees and remains toxic to bees exposed to residues for more than 38 hours following an application. This Section 18 for use of dinotefuran  in Virginia pome and stone fruit expires on October 15, 2018.

Until next time, best wishes.

San Jose crawlers active at Winchester

Greetings,

This week we recorded the onset of San Jose scale crawler movement, based on captures in stick band traps on apple branches here at the AREC. Our Spray Bulletin targets control of this generation of crawlers at second and third cover (early through mid-June), with Centaur and Esteem listed as the products rated Excellent for this purpose.

Until next time, best wishes.

Greetings,

On May 11, 2018 the Environmental Protection Agency approved the renewal of a Section 18 Emergency Exemption for use of the bifenthrin-based products, Brigade WSB, Bifenture EC, and Bifenture 10DF against brown marmorated stink bug (BMSB) in apples, peaches, and nectarines in Virginia. This exemption applies only to the products mentioned above. These and other bifenthrin-based insecticides have a Section 3 label for use in pears. The requirements of this Section 18 are that applications must be made only from the ground, at a rate of 0.08 to 0.2 lb active ingredient (a.i.) per acre, with not more than 0.5 lb a.i. per acre per season. These application rates equate to 5.12 – 12.8 fl oz of Bifenture EC, and 12.8 – 32.0 oz of Bifenture DF or Brigade WSP per acre. Seasonal maximums are 32 fl oz of Bifenture EC, 80 oz of Bifenture DF, and 72 oz of Brigade WAB. Multiple applications may be made per season, at a minimum retreatment interval of 30 days. The REI is 12 hours and the PHI is 14 days. This insecticide is extremely toxic to fish, aquatic invertebrates, and bees, and all precautions to avoid these exposures must be observed. Bifenthrin is considered one of the strongest insecticides against BMSB but can be disruptive to natural enemies of secondary pests. Consequently, we recommend its use in apples later in the season, when BMSB populations are highest. In peaches and nectarines, it can be useful from fruit set until 14 days before harvest. This Emergency Exemption expires on October 15, 2018.

Please note: The availability of bifenthrin-based products may be more limited in 2018 than in previous years. Therefore, growers wanting to use these products are urged to contact their suppliers as soon as possible.

Until next time, best wishes.

Codling moth and stink bug update

Greetings,

Management of first brood codling moth (CM) larvae is warranted if captures in pheromone traps have exceeded the threshold of 5 moths per trap per week.  Based on the biofix for CM at Winchester (May 3), 204 DD had accumulated for this pest as of May 14. Optimal timing for most of the products considered most effective for first brood CM larvae is 250 DD, which will be reached in the Winchester area by about the middle of this week.

Peak emergence of brown marmorated stink bug (BMSB) adults from overwintering sites occurs from now through the end of May, although some portion of the overwintering population typically emerges somewhat earlier, and we have captured BMSB in pheromone traps in Frederick County, VA over the last couple of weeks. Peaches and nectarines are vulnerable to it from the early stages of fruit development onward, so blocks with a history of BMSB injury or in which it has been observed this spring should be protected now. We have not yet been notified about a decision on renewals of the Section 18 Emergency Exemptions for use of dinotefuran or bifenthrin against BMSB. Bifenthrin-based products may be in short supply this year, and I will post another update when I know more about this issue.

Until next time, best wishes.

OFM and CM captures at the Winchester research station

Greetings,

After a long stretch of following daily oriental fruit moth captures, we’ve set a biofix date of April 22 for both Winchester and Rappahannock county.  This year was more challenging than most, given that flight started and then stopped for multiple days on more than one occasion during April. This is the latest oriental fruit moth biofix date (by 2 days) that we’ve seen in Winchester since 2000, reflecting the slow warm-up this year but also highlighting the usefulness of biofix and degree-day models initiated at biofix to accommodate annual variations in weather. We caught our first codling moth last night (May 1), anticipate more during this warm week, and will keep you apprised of biofix for it and for tufted apple budmoth. Our twice weekly postings of degree day accumulations, percent egg hatch, and management timing recommendations will begin this week.

Until next time, best wishes.

 

Revision to 2018 Spray Bulletin for Cherries at Petal Fall

Every year it seems that something or another slips through the cracks during our annual revision to the insecticide portions of the Spray Bulletin. These errors are usually small, but this year I have noticed something that is more substantial, so wanted to make you all aware of this right away. On page 123 of the 2018 Bulletin, all of the numbers for insecticides showing under the “Effectiveness” column for applications to cherries at petal fall are incorrect (i.e. the numbers do not reflect the products that would be recommended for each pest listed). I have attached a revised file here, showing the correct insecticide numbers for each pest, and the effectiveness rating for each. We apologize for this oversight, which appears to have occurred during revisions to the 2017 Bulletin and were carried forward to the 2018 edition.

2018 Spray Bulletin revision_Cherries at PF_4.14.18

Early season update

Greetings,

Our recent travels to extension meetings in Virginia have revealed apple and peach bud development that is much behind last year but that varies fairly widely among locations. For example, yesterday we visited an apple orchard in Rappahannock County with fruit buds still at the delayed-dormant stage. For those situations, dormant oil alone or in combination with an insecticide (numerous options in Spray Bulletin at http://pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/456/456-419/456-419.pdf) would still be an option for managing San Jose scale, mite eggs, and rosy apple aphid. In apple orchards that are further along (tight cluster to pre-pink), rosy apple aphid and tarnished plant bug are two of the direct pests targeted at this time. Assail and Beleaf are strong options for rosy apple aphid that this point, and there are a range of pyrethroids listed in our bulletin for prebloom use. We have not yet captured oriental fruit moth. Since 2000, biofix for this species (i.e. when sustained flight of the overwintering generation begins) has ranged from March 20 to April 20, with an average of about April 10, so this is not the latest year but is getting toward the later end of the historical range. Oriental fruit moth captures may begin during the upcoming warm period, but whether we record sustained flight over several days, and therefore set a biofix date, remains to be seen.  For apple and peach orchards that have had issues with oriental fruit moth, mating disruption, whether a sprayable formulation or hand-placed dispensers would be a strong option when first captures in pheromone monitoring traps have occurred.  Alternatively, in apple orchards which have had pressure from oriental fruit moth and codling moth, hand-placed dispensers for mating disruption against both species simultaneously can be deployed during bloom, providing different lengths of protection depending on the product used. In apple orchards where codling moth has been most problematic, mating disruption dispensers for this species alone can also be placed in orchards during bloom.  A long-standing recommendation for peach pest management in our area has been to begin insecticide applications against, plum curculio, catfacing insects, oriental fruit moth, and aphids at petal fall, but only if San Jose scale has not been an issue in recent seasons (which would require management at the dormant stage of fruit bud development). Thereafter, a tight schedule of applications against these pests, at shuck split and shuck fall is recommended.

Until next time, best wishes.