Apple insect pest degree day models

Background Information for this page
Return to radar list for Monmouth ME
Weather data for Monmouth ME.  Forecast values begin September 3, 2008
Key Dates are highlighted in yellow boxes
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Borers  -  Roundheaded Appletree Borer  RAB    &    Dogwood Borer
RAB adult emergence begins:  June 8.    Peak emergence:  June 24.
RAB egglaying begins:  June 17.    Peak egglaying period roughly:  July 8  to July 23. 
First RAB eggs hatch roughly:  July 2.    Peak hatch roughly:  July 23  to August 12.
First Dogwood borer egg hatch roughly:  July 12.    Peak hatch roughly:  August 15.
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Codling Moth   CM
1st generation, first sustained trap catch biofix date:  May 27, Tuesday 
Codling moth development as of September 3: 
2nd generation adult emergence at 69% and 2nd generation egg hatch at 30%

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 19,  Thursday
(= 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 27,  Friday
(= target date where one spray needed to control 1st generation codling moth)
2nd generation 7% CM egg hatch:  August 20,  Wednesday
(= 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:  September 3,  Wednesday
(= 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 23,  Friday.          Peak trap catch:  June 1.
2nd LAW flight begins around:  July 20,  Sunday
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Mullein Plant Bug   MPB 
The expected 50% egg hatch date is:  May 31,  Saturday,
which is 3 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:  June 5,  Thursday
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Obliquebanded Leafroller   OBLR 
1st generation OBLR flight begins around:  June 20,  Friday
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):  July 7,  Monday
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 15,  Tuesday
If first OBLR late instar larvae sample is below threshold, date for confirmation follow-up:
July 19,  Saturday
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Oriental Fruit Moth   OFM 

1st generation OFM flight starts, and first treatment date if needed:  May 14,  Wednesday
1st generation - second treatment date, if needed: June 10,  Tuesday
2nd generation OFM flight begins around:  July 11,  Friday
2nd generation - first treatment date, if needed: July 19,  Saturday
2nd generation - second treatment date, if needed: August 1,  Friday
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Plum Curculio   PC 
 Increased risk of PC damage as McIntosh and similar cultivars increase fruit size:
 June 1,  Sunday
 Earliest safe date for last PC insecticide spray:  June 16,  Monday
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 Tuesday, July 8.
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Redbanded Leafroller   RBLR 
1st RBLR flight begins around April 28,  Monday.
  Peak trap catch and approximate start of egg hatch: May 15, Thursday.
2nd RBLR flight begins around July 14,  Monday.   
Peak catch and approximate start of egg hatch: July 23
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San Jose Scale   SJS
First adult SJS caught on trap:  May 27,  Tuesday
1st generation SJS crawlers appear:  June 30,  Monday
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Spotted Tentiform Leafminer    STLM
(and presumably Apple Blotch Leafminer)
1st STLM flight, peak trap catch:  May 22,  Thursday
1st generation sapfeeding mines start showing:  June 1,  Sunday. 
Optimum sample date is around Monday, June 2,
when a larger portion of the mines are visible.
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2nd STLM flight begins around:  June 27,  Friday
Rough guess of when 2nd generation sap-feeding mines begin showing:  July 16,  Wednesday.  
Optimum first sample date for 2nd generation STLM sapfeeding mines is
July 24,  Thursday
Second optimized sample date for 2nd generation STLM sapfeeding mines, if needed:
July 31,  Thursday
Third optimized sample date for 2nd generation STLM sapfeeding mines, if needed:
August 15,  Friday
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Tarnished Plant Bug    TPB 
Rough guess of when TPB begin showing on traps:  April 23,  Wednesday
Rough guess of when TPB damage results in deformed fruit at harvest
 instead of aborted bud: May 8,  Thursday
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White Apple Leafhopper   WAL 
1st generation WAL found on apple foliage:  May 26,  Monday
2nd generation WAL found on apple foliage:  August 26,  Tuesday

* 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.