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Assessing the Baseline for Insecticide Resistance in New York State Codling Moth Populations. Peter Jentsch Extension Associate - Entomology. Purpose for the study: Internal worm biology Shifts in pest management. Objectives & results of the study. Preliminary conclusions.
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Assessing the Baseline for Insecticide Resistance in New York State Codling Moth Populations. Peter Jentsch Extension Associate - Entomology
Purpose for the study: • Internal worm biology • Shifts in pest management. • Objectives & results of the study. • Preliminary conclusions
‘The 1% Problem’ Rejections of Processing Shipments From Western NY Processing Orchards Due to Increasing Internal Worm Infested Fruit 2001: 20 loads of rejected fruit 2002: 80 loads of rejected fruit from 42 growers in WNY1 2005: 100 loads of rejected fruit from 60 farms. 1. Rhode Island Greening (12 loads), Monroe (12 loads), Cortland (7 loads), Idared (7 loads), Jonagold (6 loads), Rome (4 loads)
Classification of internal Lepidoptera larvae in fruit from infested New York apple orchards in 2002 (Reissig). Percentage of larvae Orchard OFM or LAW Codling moth B-1 84 16* D-1 97 3 E-1 90 10* L-1 5 95* V-1 58 42* D-2 100 0 M-1 100 0 P-1 100 0 S-1 100 0 S-2 100 0 *4 Orchards with > 10% CM infested fruit. Only 10 of 20 orchards had > 10 larva / sample.
Identification of non-codling moth larvae collected from severely infested orchards during 2002 in NY (Reissig1). Site # larvae OFM (% of larvae2) LAW (% of larvae2) #1 15 94 6 #2 33 94 6 #3 49 94 6 #11 24 83 17 #35 42 67 33 #40 25 84 16 #46 12 83 17 1. THE COMPACT FRUIT TREE, VOLUME 36, NUMBER 1, 2OO3 (IDFTA) 2. Identification by Dr. Greg Krawczyk, Penn State.
Classification of internal Lepidoptera larvae in fruit from infested New York apple orchards in 2005-2006 (Breth). Percentage of larvae ID - 2005 Codling moth 55.5 OFM 19.5 LAW 7.0 Unknown 16.5 Percentage of larvae ID - 2006 Codling moth 49.0 OFM 24.0 LAW 6.0 Other 6.0 (fruit fly maggot, ECB) Unknown 15.0 (tiny or no worm found, sign of worm only) 168 apple samples
Possible causes of internal worm management failures: Insecticide resistance Endemic population with refined genetics Dr.V.Harris, M.Angst, and P. Carudel, 2001 meeting of the Insecticide Resistance Action Committee
Insecticide resistance Initial resistance levels in various states to Azinphos-methyl (AZM)(Guthion) • California & Washington: 4-7x resistance (1997) • Pennslyvania: 6x (2002) • Michigan: 2-5x resistance (2007) Demonstrated correlated cross-resistance to AZM: pyrethroids, insect growth regulators tebufenozide (Confirm) and methoxyfenozide (Intrepid). Assail: 1.7-4.8x resistance (2003-CA) Phosmet: 7-8x resistance (2007-MI) Granuloisis virus (2007-Germany)
Possible causes of internal worm management failures: Population density Application management: Insecticide use shift - reduced risk Late season use reductions (OFM / LAW) Timing to 1st hatch (DD modeling) Coverage (water / air volume, nozzle failure) Weathering IV. Orchard management: Over cropping, dense canopy VI. Combination of factors.
NY Internal Lepidoptera Complex: 3 species Family: Tortricidae Codling moth Cydia pomonella (Linnaeus) 2 generations / year Oriental fruit moth Grapholitha molesta (Busck) 3 generations / year Lesser apple worm Grapholita prunivora Walsh 2 generations / year
Adult Flight of the Internal Lepidopteran Complex on Apple WNY (Williamston, Wayne, County)
Adult Flight of the Internal Lepidopteran Complex on Apple Hudson Valley of NY (Highland, NY)
Adult Flight of the Internal Lepidopteran Complex on Apple PC OBLR AM OBLR AM LAW LAW OFM OFM OFM CM CM GT TC P Bloom PF 1C 2C 3C 4C 5C 6C 7C 8C 28 May 1 Aug. 5 July 1 May 15 Aug. 15 July 14 May 10 June 25 June 21 April 27 April 21 March
Our study: Objective 1: Evaluate the efficacy of azinphos-methyl against NYS adult populations. Objective 2: Evaluate the efficacy of azinphos-methyl against NYS larval populations. Objective 3: Evaluate insecticides for efficacy on populations of susceptible larva using topical evaluations and residue of treated fruit.
Objective 1: Evaluate the efficacy of azinphos-methyl against adult populations using topical bioassays. 10 sites 4 WNY sites (Williamson (2) & Wolcott, Wayne Co. Brockport, Monroe, Co.) 2 Northern Hudson Valley: Burnt Hills, Altamont 4 Southern Hudson Valley: Highland, Milton, Marlboro Obtained live adults using pheromone traps & removable liners. Individuals were treated using 1 micro liter applications to the dorsal thoracic plate using field rates (+LI700) OP, pyrethroid, neo-nicotinoid’s 0.5, 1.0 and 1.5x field rates.
Our study: • Objective 2: WNY • To obtain infested fruit from sites with prior infestations (rejected loads), cage and isolate pupa, rear mating adults to oviposit, obtain eggs, rear larvae in successive generations to evaluate insecticides for resistance. • Relatively few apples were obtained from WNY sites as significantly less internal worm damage had occurred in 2008. • Fruit containing internal worm were subsequently shipped to PA for testing on newer chemistries (Delegate & Altacor). • Follow-up to obtain greater numbers of fruit from WNY will begin in June of 2009.
Objective 2 - ENY ENY infested fruit were difficult to obtain in commercial orchards. We gathered infested fruit from abandoned trees adjacent to commercial production. High levels of parasitism (Ichneumonidsp.) in larva obtained throughout Hudson Valley samples. Follow-up to obtain greater numbers of fruit from WNY will begin in June of 2009.
Objective 3: Obtained OP susceptible codling moth (Benzon labs, PA), rear larvae in successive generations to evaluate baseline susceptibility of insecticides for efficacy. I. Treated larva with 1 micro liter doses of field rates of insecticides to determine efficacy. Evaluations at 1-24 hours. Surviving larva placed on media to determine developmental success. II. Placed larva on apple using field rates of insecticides to determine efficacy. Evaluations at 1-14 days.
Wax covered media, CM frass and CM pupa along cup lid.
Conclusions • Results from adult CM bioassay indicate levels of AZN resistance in 2 WNY orchards that may be contributing to control failures in processing orchards using AZN in pest management. • Reductions in CM efficacy indicate cross resistance potential of WNY populations to pyrethroid and neo-nicotinoyds that may be contributing to control failures of pyrethroids in processing orchards using AZN pest management. • Northern Hudson Valley populations with a recent history of AZN use had lower levels of susceptibility than orchards not having used AZN in the past >5 years. • Southern Hudson Valley Orchards have CM susceptibility levels to AZN similar to lab susceptible populations. Peter Jentsch Extension Associate - Entomology