Happy spring! It just started snowing again here but that’s still okay.
I’ve decided to expand (and also contract – good trick, huh?) the program I did last summer with some growers to send out information on scouting and treating for insect pests based on growing degree days.
You won’t get information specifically for the weather station you choose, but I will give information for 3 sites – Southold (the warmest), Geneva (somewhere in the middle) and Champlain (the coldest). If you want to promote your site as the warmest or coldest, let me know.
GDD for March 6 – and the 5 day forecast for March 11
Southold 3 3
Geneva 0 0
Champlain 0 0
I’m a little late as the earliest insects are out starting about 7 GDD. You need to be ready to scout and to treat if necessary. (Sorry, Long Island!). We use 50F as the base temperature and calculate GDD starting March 1.
Your mission (should you choose to accept it) is to go to the NEWA (Network for Environment and Weather Applications) site and find your best weather station. http://newa.cornell.edu/index.php?page=station-pages (Click on New York under Station Pages if NY doesn’t open automatically). When you click on the station name, you will get information on the site – elevation might be important and you can compare the Daily Summary temperatures to what you have had at your farm. Questions? Send me a note.
So what should you be scouting for if GDD has started to accumulate in your area?
Spruce spider mite eggs (7-121) – Scout for eggs on trees previously infested and the surrounding trees (fir, Doug fir, pine, spruce). Egg hatch is before bud break and often starts on the south side of the tree. A dormant oil spray (not on blue spruce) should occur prior to egg hatch.
Elongate hemlock scale (7-120) – Check under scale covers for living scales on trees previously infested (fir, Doug fir, pine, spruce). Remove heavily infested trees before bud break (and carefully – don’t spread scale to uninfested trees when moving them). You can use a dormant oil treatment for EHS.
White pine weevil (7-58) – Scout for adults on spruce, pine, Doug fir, occasionally fir – especially in areas where you have had it previously. You can use Tedders traps with a lure. An indication is soil temperatures above 50F on the sunny side of the tree. You can also look for droplets of sap on the leaders indicating feeding sites. Treat top 1/3 of the tree when adults are first found.
Pales (7-121) and Eastern pine weevil (7-100) – Destroy stumps before adults emerge. Remove cull piles and dying trees. Adults will also be attracted to Tedders traps. For Pales weevil, pull duff away from last year’s stumps to look for adults. Pines, occasionally Doug fir and spruce.
Eriophyid mites (7-22) – Scout for eggs on branches with gray or rusty color. Use dormant oil before bud break.
That should keep you off the streets! Your records of where insects were last year are invaluable in making scouting easier this year!