Aphid Day 2019
On 9/26 I wondered if the aphids were going to miss their chance this year. At that point it looked like there wasn't another warmish day coming.
Nope, they didn't miss. This afternoon, 3PM 10/16, we hit 66 by my thermometer, and the aphids are just now massively swarming.
No chance of another 60, at least by Weather.com predictions:
So here we go after all!
[This is the tenth time I've noted it here. Aphid Day in 2010 was the
first of Oct, in 2011 it was the
end of Oct, in 2012 the
first of Oct, in 2013 the
last part of Oct, in 2014 (with an actual picture) the
end of Sept, in 2015
end of Sept, in 2016
end of Sept, in 2017
near end of Oct, in 2018
around mid Oct,
and now in 2019
around mid Oct. ]
= = = = = BELOW HERE IS REPRINT of the original.
Every year in Spokane the end of summer is marked by the swarming of tiny white-winged flies.
Insects don't waste much time in adulthood; lots of bugs live several years as larvae and only a few days as adults.
These flies take it to an extreme. Adults are minimally equipped to get in the air and reproduce. They don't have as much brain power as other flies, nor do they have hard shells. Instead of flying purposefully, they drift with the wind like seeds, and die as soon as they bump into anything even at near-zero drifting speed. Result: for a couple of days, your face and clothes are covered with semi-liquid insects.
Despite their lack of navigation, they must have some kind of superior instinct or 'community intelligence', because picking the
last warm day is much harder than picking the
first warm day of spring. Termites and ants don't need to calculate their swarming day; they only need a simple neuron to detect when temperature rises past a certain threshold, plus an emitted pheromone to trigger the avalanche.
But how do these flies determine that today is not just warm, but the
last warmth for their generation? They must be sensing something besides temperature.
At any rate, they serve as a reliable sign for us, even if our supercomputers can't match their calculations.
Polistra has put it into
folk-wisdom format:
White flies swarming, no more warming.
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[Artistic note: the swarm in the animation turned out nicely, but Polistra's head looks steroid-swollen and South-Park-ish for unknown reasons. Maybe she's allergic to the bugs.]
[Technical note: According to
some sources, these bugs are smoky-winged ash aphids,
Prociphilus americanus.]