Apple insect pest degree day models

Background Information for this page
Return to radar list for Middletown RI
Weather data for Middletown RI.  Forecast values begin September 2, 2008
Key Dates are highlighted in yellow boxes
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Borers  -  Roundheaded Appletree Borer  RAB    &    Dogwood Borer
RAB adult emergence begins:  May 31.    Peak emergence:  June 11.
RAB egglaying begins:  June 9.    Peak egglaying period roughly:  June 26  to July 9. 
First RAB eggs hatch roughly:  June 24.    Peak hatch roughly:  July 11  to July 29.
First Dogwood borer egg hatch roughly:  June 30.    Peak hatch roughly:  August 1.
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Codling Moth   CM
1st generation, first sustained trap catch biofix date:  May 17, Saturday 
Codling moth development as of September 2: 
2nd generation adult emergence at 100% and 2nd generation egg hatch at 95%

In most orchards, insecticide targetted against plum curculio and apple maggot prevent codling moth damage.  If targetted codling moth control is needed, key management dates are shown below:
1st generation 3% CM egg hatch:  June 9,  Monday
(= target date for first spray where multiple sprays needed to control 1st generation CM)

See Codling moth tables for follow-up spray dates to maintain protection
through 1st generation CM egg hatch.
1st generation 20% CM egg hatch:  June 14,  Saturday
(= target date where one spray needed to control 1st generation codling moth)
2nd generation 7% CM egg hatch:  July 27,  Sunday
(= target date for first spray where multiple sprays needed to control 2nd generation CM)
 
If needed and allowed by preharvest interval,
see the August Codling Moth table for follow-up spray dates.
2nd generation 30% CM egg hatch:  August 4,  Monday
(= target date where one spray needed to control 2nd generation codling moth)
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Lesser Appleworm   LAW 
1st LAW flight begins around:  May 11,  Sunday.          Peak trap catch:  May 22.
2nd LAW flight begins around:  July 8,  Tuesday
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Mullein Plant Bug   MPB 
The expected 50% egg hatch date is:  May 25,  Sunday,
which is -1 days before rough estimate of Red Delicious petal fall date.
Most accurate time for limb tapping counts, but possibly after MPB damage has occurred,
is 90% egg hatch date:  May 29,  Thursday
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Obliquebanded Leafroller   OBLR 
1st generation OBLR flight begins around:  June 10,  Tuesday
Where waiting to sample late instar OBLR larvae is not an option
(= where OBLR is known to be a problem,
and will be managed with insecticide against young larvae):
Early egg hatch and optimum date for initial application of B.t., Intrepid, Proclaim, SpinTor or other insecticide with comparable efficacy against OBLR
(with follow-up applications as needed):  June 25,  Wednesday
Where waiting to sample late instar OBLR larvae to determine need for treatment
is an option, or to check on results from earlier sprays:
Optimum sample date for late instar summer generation OBLR larvae: July 4,  Friday
If first OBLR late instar larvae sample is below threshold, date for confirmation follow-up:
July 7,  Monday
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Oriental Fruit Moth   OFM 

1st generation OFM flight starts, and first treatment date if needed:  April 30,  Wednesday
1st generation - second treatment date, if needed: June 2,  Monday
2nd generation OFM flight begins around:  June 29,  Sunday
2nd generation - first treatment date, if needed: July 6,  Sunday
2nd generation - second treatment date, if needed: July 17,  Thursday
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Plum Curculio   PC 
 Increased risk of PC damage as McIntosh and similar cultivars increase fruit size:
 May 22,  Thursday
 Earliest safe date for last PC insecticide spray:  May 29,  Thursday
Plum curculio spray intervals
 If relying on repellance by Surround instead of PC mortality by insecticide,  Surround coverage should be maintained until PC egglaying begins to naturally decline around Saturday, June 28.
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Redbanded Leafroller   RBLR 
1st RBLR flight begins around April 19,  Saturday.
  Peak trap catch and approximate start of egg hatch: May 2, Friday.
2nd RBLR flight begins around July 2,  Wednesday.   
Peak catch and approximate start of egg hatch: July 10
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San Jose Scale   SJS
First adult SJS caught on trap:  May 17,  Saturday
1st generation SJS crawlers appear:  June 19,  Thursday
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Spotted Tentiform Leafminer    STLM
(and presumably Apple Blotch Leafminer)
1st STLM flight, peak trap catch:  May 10,  Saturday
1st generation sapfeeding mines start showing:  May 22,  Thursday. 
Optimum sample date is around Saturday, May 24,
when a larger portion of the mines are visible.
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2nd STLM flight begins around:  June 16,  Monday
Rough guess of when 2nd generation sap-feeding mines begin showing:  July 4,  Friday.  
Optimum first sample date for 2nd generation STLM sapfeeding mines is
July 11,  Friday
Second optimized sample date for 2nd generation STLM sapfeeding mines, if needed:
July 17,  Thursday
Third optimized sample date for 2nd generation STLM sapfeeding mines, if needed:
July 26,  Saturday
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Tarnished Plant Bug    TPB 
Rough guess of when TPB begin showing on traps:  April 13,  Sunday
Rough guess of when TPB damage results in deformed fruit at harvest
 instead of aborted bud: April 24,  Thursday
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White Apple Leafhopper   WAL 
1st generation WAL found on apple foliage:  May 15,  Thursday
2nd generation WAL found on apple foliage:  August 3,  Sunday

* Rose leafhopper is easily confused with WAL but has different generation dates.
Rose leafhoppers typically immigrate into orchards from border row host plants
between 1st and 2nd generation WAL.