The new car phenomenon

…is what I was initially going to call this post. I now know the new car phenomenon to be a well-documented one, but when I first discovered it I was blown away. It was sometime in the mid-90s when my family got a new Plymouth Voyager. And then blammo – Plymouth Voyagers everywhere I looked. While it was a brand new model, it had become inexplicably popular overnight. Where were all these Voyagers hiding before we got ours? Over the years I’ve experienced this same phenomenon again and again – discovering something new and then suddenly finding that thing over and over again. Not surprisingly, there’s a codified name for this cognitive illusion: “the frequency illusion.” It’s also informally referred to as the Baader-Meinhof Phenomenon (why it’s named after a German terrorist group is another story).

The Baader-Meinhof Complex (aka Frequency Illusion)

Hemlock pollen cone just emerging (Centennial Woods)

Most of my Baader-Meinhofs are now natural history related. I spend some time keying out the different species of shrubs, and then all of a sudden I see them everywhere. Or I learn a new bird song and then I hear it all over. A few days ago I was running in Centennial Woods when I spotted a hemlock with a developing cone. I had wanted to get a photo of that stage of development so yesterday I headed into Centennial Woods with the intention of eventually winding up at the tree. I thought I’d also check back in and see how the pollen cones (above) were coming along.

New growth on Hemlock (Centennial Woods)

I was having trouble finding either male or female cones so I kept stopping at hemlocks to browse the new growth (almost all the new growth on conifers this time of year is electric green so it’s easy to quickly scan a tree looking for developing cones). Most of the trees I explored were on the smaller/younger end of the spectrum so I wasn’t anticipating sexual structures. But with hemlocks, which are extremely shade tolerant and can be extremely slow growing, a small tree can be a very old tree. I have a tree cookie of a hemlock about 2.75″ in diameter and over 100 years old (see post here), so I figured even the smaller trees might have reproductive structures on them.

A hemlock spittle bug (Aphrphora cribrata)

As I was perusing the branches I noticed a spittle bug. I was a little surprised because I mostly notice these tiny sap-sucking insects on herbaceous plants in meadows. In the back of my mind I took some quick mental notes about where it was placed on the twig and then kept moving in search of the real treasure I was after. As I was making my way to the next hemlock another white splotch caught my eye. Then another. And another. Soon I was seeing white splotches – those little spittle bug spit “nests” – everywhere.

Spittle bug on Hemlock (Centennial Woods)

I’ve spent lots of time in hemlocks (they’re great for climbing) and with them (they’re great for tea) and on them (they’re great for making sleeping pads for winter shelters) and yet somehow I’d manage to overlook these little critters up to this point. I popped the bubbles around one of the nymphs (larva of insects that don’t undergo a complete metamorphosis) to see what it looked like. It had a beautiful glossy black head and thorax with an orange translucent abdomen that kept expanding and contracted. I watched for about 15 minutes after I’d removed the spit but it didn’t rebuild. It forms the spit by blowing bubbles out of its butt end.

A hemlock spittle bug (Aphrphora cribrata)

The spit is a protective layer that shields the nymph from predators (the liquid I’ve tasted in the past had a slightly bitter flavor to it). The nymphs also have thin exoskeletons and so the spit provides a layer of moisture to prevent it from drying out. The trapped air also insulates the insect from temperature fluctuations. I’m excited to head back when I have more time to watch it blow bubbles. Eventually I did wind up finding the hemlock cones I’d been looking for, but not before realizing that there were dozens and dozens of insects living in these woods that I’d previously ignored.

Female cone and new growth on a hemlock (Centennial Woods)


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