Apple insect pest degree day models

Background Information for this page
Return to Apple list for Easthampton MA
Weather data for Easthampton MA.  Forecast values begin September 3, 2017
 
Borers  -  Roundheaded Appletree Borer (RAB)   &   Dogwood Borer
RAB egglaying begins:  June 7.    Peak egglaying period roughly:  June 23  to July 7. 
First RAB eggs hatch roughly:  June 22.    Peak hatch roughly:  July 8  to July 27.
First Dogwood borer egg hatch roughly:  June 21.    Peak hatch roughly:  July 26.
Codling Moth  (CM)
1st generation, first sustained trap catch biofix date:  May 15, Monday 
Codling moth development as of September 3: 
2nd generation adult emergence at 100% and 2nd generation egg hatch at 89%

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,  Friday,
= 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 13,  Tuesday,
= target date where one spray needed to control 1st generation CM.
2nd generation 7% CM egg hatch:  July 28,  Friday,
= 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 7,  Monday,
= target date where one spray needed to control 2nd generation CM.
Lesser Appleworm   LAW 
1st LAW flight begins around:  May 10,  Wednesday.          Peak trap catch:  May 18.
2nd LAW flight begins around:  July 9,  Sunday.
Mullein Plant Bug   MPB 
The expected 50% egg hatch date is:  May 13,  Saturday,
which is 5 days before rough estimate of Red Delicious petal fall date.
Most accurate time for limb tapping counts, or treatment if needed,
but possibly after some MPB damage has occurred,
is 90% egg hatch date:  May 18,  Thursday.
Obliquebanded Leafroller   OBLR 
1st generation OBLR flight begins around:  June 8,  Thursday.
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., Delegate, Proclaim, Intrepid, Rimon, Altacor, Belt, pyrethroid or other insecticide effective against OBLR
(with follow-up applications as needed):  June 21,  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: June 30,  Friday
If first OBLR late instar larvae sample is below threshold, date for confirmation follow-up:
July 4,  Tuesday.
Oriental Fruit Moth   OFM 

1st generation OFM flight starts:  April 27,  Thursday.
1st generation 55% egg hatch and first treatment date, if needed: May 27,  Saturday.
2nd generation OFM flight begins around:  June 25,  Sunday.
2nd generation - first treatment date, if needed: July 3,  Monday.
2nd generation - second treatment date, if needed: July 15,  Saturday.
Plum Curculio   PC
 Increased risk of PC damage as McIntosh and similar cultivars increase fruit size:
 May 18,  Thursday.
 Earliest safe date for last PC insecticide spray:  June 6,  Tuesday.
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 24.
Redbanded Leafroller   RBLR 
1st RBLR flight begins around April 14,  Friday.
  Peak trap catch and approximate start of egg hatch: April 29, Saturday.
2nd RBLR flight begins around June 26,  Monday.   
Peak catch and approximate start of egg hatch: July 9.
San Jose Scale   SJS
First adult SJS caught on trap:  May 17,  Wednesday.
1st generation SJS crawlers appear:  June 17,  Saturday.
Spotted Tentiform Leafminer   STLM
(and presumably apple blotch leafminer)
1st STLM flight, peak trap catch:  January 1,  Sunday.
1st generation sapfeeding mines start showing:  May 18,  Thursday. 
Optimum sample date is around Friday, May 19,
when a larger portion of the mines are visible.
2nd STLM flight begins around:  June 14,  Wednesday.
Rough guess of when 2nd generation sap-feeding mines begin showing:  July 2,  Sunday.  
Optimum first sample date for 2nd generation STLM sapfeeding mines is
July 9,  Sunday.
Second optimized sample date for 2nd generation STLM sapfeeding mines, if needed:
July 16,  Sunday.
Third optimized sample date for 2nd generation STLM sapfeeding mines, if needed:
July 27,  Thursday.
Tarnished Plant Bug    TPB 
Rough guess of when TPB begin showing on traps:  April 12,  Wednesday.
Rough guess of when TPB damage results in deformed fruit at harvest
 instead of aborted bud: April 24,  Monday.
White Apple Leafhopper   WAL 
1st generation WAL found on apple foliage:  May 12,  Friday.
2nd generation WAL found on apple foliage:  August 4,  Friday.
* 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.