What do insects do in the winter? It depends on the species! Some overwinter as adults, others as eggs, some as pupae.
The Pine Tube Moth (Argyrotaenia pinatubana) overwinters as a pupa inside a tube made of pine needles. I walked through the woods for decades and never noticed them. Someone pointed one out to me and now… well… I can’t walk past a White Pine without seeing a tube. (Isn’t weird how you learn a new word, or see something new outside that you never noticed before… and suddenly – it’s EVERYWHERE?)
A mature caterpillar uses silk to create a tube by binding up to twenty needles. They usually eat the ends off the needles that make up the tube, and perhaps a few nearby needles.
If you find short tubes – less than one inch, these are likely abandoned tubes built by immature caterpillars to protect themselves while eating.
I’ve never seen the critter that makes the tube. I poked around on the ‘net, though, and found the images that follow. Click on them to go to the sources.
Pine Tube Moth Caterpillar
Pine Tube Moth Adult
OK, now you go look for tubes made of pine needles. Report back! Once spring (early to mid-April) arrives, we’ll have to go looking for adults, then eggs and caterpillars. (I wonder what the eggs look like, hmmm…?) Apparently there will be two generations before winter… so we can look again in July for adults.
Learn more here:
A Passion for Nature 
This is fascinating, especially since I just got done with an entry about Luna Moths on my blog. I will look for tubes this winter!
I have lots of white pines in my yard. I’m going to look for this also.
That is so very true … I never noticed galls until this summer and once I knew what a gall was … I DID see them everywhere in all kinds of forms! I’ve never seen these Pine Tubes though. Most of our pines have gone the way of the pine beetle … so it may be a while before we get a mature enough tree to notice these critters. Still, I’ll keep my eyes peeled now that I know what to look for. We have mostly Lodge Pole Pines in our area.
@Eileen – I found this info on another website:
A related species, the jack pine tube moth (Argyrotaenia tabulana), causes similar symptoms on jack, lodgepole, and whitebark pines in the Rocky Mountain states and the Canadian provinces of Alberta, Manitoba, and Saskatchewan.
from: http://ctrees.cas.psu.edu/Pest%20Sheets/pinetubemoth.htm
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