Sunny Schneiderhan, starette landscape gardener beautifying her space in Dinkytown USA, reported active sawflies on a mugho pine last Wednesday.
Fortunately, for those of us who live in suburban Twin Cities where our horticultural zone is not yet #5, we usually have a four or five day respite from such attacks than our city brothers and sisters who grow Scot’s and mugho pines.
Do note and remember that Spring on a sunny South and the Southwest exposure of your home expecially within ten to fifteen feet from the house foundation, is often two to three weeks earlier and warmer than the geography on the north side.
Few insect pests can do more damage in such a short period of time to their favorite plant food than sawflies. Normally we sound the alarm, that is the damage, around May 14 give or take a week depending upon where you live in the Twin Cities.
It isn’t every year we Minnesotans have a winter without a January or February. Many, if not most of our deciduous woody plants are already leafying out into what I call the Lacy Foliage Look of our Spring……the time when the evergreen conifer forms no longer dominate the winter landscape.
The Lacy Foliage look lasts about five or six days, depending on the temperature. In just a few days, sun willing, the Lacy Look to upper levels of our neighborhood landscaping scenery will yield to five to six months of green leaf mass and its shade.
Although not every plant species is equally affected by such an early spring, our Spring, 2012 is occurring about five weeks earlier than the average of our outdoords of the past half century.
The beginning of sawfly activity, meaning their munching on the foliage of your favorite Scots Pine, Mugho Pine, and all of their cultivars, seems to coincide with the Lacy Look calendar dates.
The mother sawfly lays her countless eggs into last year’s crop of new needles sometime in August where they remain apparently quite unalert but cozy until Lacy Look week of the following Spring. The warmth of Spring arouses the critters who, very hungry from their previous condition, begin chewing away from the insides of each infected needle. These needles have already been damaged beyond repair.
But, as Nature would have it however, most homeowners, I and other landscape gardeners included, may notice nothing at all……until very close personal inspection. For eyes of my age that inspection has to be within a foot or two from the scene of the crime.
For those of you who know something about a riled Medusa of ancient Greek lore, expect to see the same if you happen to bump a branch of you pine victims and notice the writhings and wigglings of what appears to be pine needles. Alas, pine needles can, on their own, neither writhe or wiggle…….This repulsive display is symptomatic of an active saw fly attack.
If not combatted, either by the end of the week or by next year’s crop and the years’ following, your susceptible pines will likely have no foliage left at all, except the ones producing food for baby sawflies. A pine without needles is not a pretty sight.
Immediate attention: Shake the branchings to dislodge the wormy creatures from the needles. I am told that most have no ability to crawl back up to trunk to their previous dinner table location.
If your garden hose is handy, hit the ‘worms’ with the hardest water pressure possible, again, to dislodge them from their dinner table. Reach the highest branchings possible.
If you remember having seen them or their damage on the pine last year, you can apply an insectide, Sevin or Malathion at this very time when the larvae on hatching and eating.
For best control of sawfly infestation on pine over a number of years, apply a systemic insecticide which includes sawflies on the lable, to each individual suffering from the pests sometime in midAugust.
As soon as it stops raining I plan to examine my mugho and Scot’s pines for any sawfly activity. Occasionally the pest will attack the Eastern White Pine, but the damage is usually less devastating.