Naturally Distracted: Adventures in Woolly Alder Aphid Tracking

Naturally Distracted with Kirk Gentalen

Last time we all got ‘Distracted’ we talked about the ‘Baader-Meinhof Phenomenon’ (BMP) or ‘Frequency Illusion’ patterns in nature observation. BMP can be summed up as ‘once you notice it, you see it … a lot’.

There is an opposite observational pattern to the BMP – The ‘Anti-Baader-Meinhof Phenomenon.’ ABMP, if you will. As in, once you see it, you stop looking for it. Nature is weird.

For me, ABMPs are usually reserved for sightings that require a little discipline. To experience some critters and nature stuff you must ‘meet them halfway’ (or more!). And once you’ve made the effort sometimes you just don’t find yourself going halfway again. A quarter of the way, sure. Maybe.

Take this example – A major observational focus for me from 2018-2025 had me examining every Woolly Alder Aphid patch I crossed paths with. I knew of a bunch of Aphid colonies, and from June-August each year I would visit them often, in hopes of seeing Harvester butterfly caterpillars. Going ‘out of my way’ to ‘put myself in the best location’ and ‘set myself up for success’. The things you do for caterpillars.

Sure enough, in 2025 my efforts ‘paid off’ as I did see the only carnivorous butterfly caterpillar in North America. Learn about it here.

This summer, I checked on the colonies, but the energy was different  – I found myself waving to them rather that getting my face right in there – total ABMP. My mind went on to the next distraction (other insects) that had taken hold. Always something.

Now, it’s the Fall of ‘26, and the leaves are doing what they are told to – fall! As ferns die back and shrubs drop their leaves, views within the woods are opening wide. With new views come new sights, and suddenly I’m coming across woolly alder aphid colonies that I hadn’t noticed before BMP. ‘New to me’, as we say.

There’s one ‘mega-colony’ that demanded to be observed – and turned out to be the biggest colony I have seen with some of the biggest patches of fluff! Plus patches of wool! Hot stuff!

The fire was back immediately – I had to get in close. I could be heard mumbling, ‘Let’s go!’ with every new patch added to the colony total. Seventy is wild, just wild.

In previous autumns, I’ve crossed paths with winged adults at Woolly Alder Aphid colonies. Winged aphids take to the air to find a new host, open up a new range, or establish a new colony. The adults in this ‘new’ mega-colony were wingless, naked (no wool!) and marching down the trees! What?

Turns out there are two types of life cycles for the Woolly Aphids. One where they grow wings and fly off, and another where adults overwinter at the base of their alder!  Woolly Alder Aphid migration to wintering grounds on the ground! So cool!

To make things even cooler, three of the woolly patches had obviously been impacted/attacked by something. They looked different, they looked ‘smeared’. This is cool in the sense that the ‘smears’ looked a lot like the ‘smear’ I’d seen left by the Harvester caterpillar the summer before. Could this mean that three Harvester caterpillars had feasted on the ‘new’ colony this summer? I’d say –Yes! Three at least! Tracking Harvesters – Harvester Tracker!

Between the size of the colony, the marching migration of gazillion adults, and sign of Harvester caterpillars – I can tell you this mega-colony is going to be a mega-distraction in the summer of ’27!  

Every time down a trail is different, and there is nothing like watching leaves fall, and then seeing the secret treasures they were hiding.

See you out there.