Please Pass the Salt

As a member of the Conservation Commission, my opinion about road salt is that it is a necessary evil and should be used as sparsely as possible. But I ran into a few insects recently who have a different view. They are thrilled that we have provided free salt, it makes their lives much easier.

The first salt lovers I found were a bunch of sweat bees (most likely Augochlora pura) who are making use of a network of small holes in the base of an ancient dead maple on Canaan Street (the north end, lake side). This is the same dead maple that a year ago hosted a bevy of crossbills similarly seeking salt. Now, its salt-saturated dead wood hosts scores of beautiful metallic green bees who use the holes dug by other insects as nests. Since sweat bees crave salt (they are called sweat bees because they try to steal that salt from your sweat and drive you bonkers doing it) these nests provide a two-fer: holes to nest in and, thanks to years of road treatment, a salt lick!

This is a sweat bee about to duck into her nest in an ancient maple on Canaan Street.

The second bunch of salt lovers might have already caught your attention this last week or two. Eastern tiger swallowtails are everywhere. They are those beautiful yellow and black butterflies that you keep bumping into. The males, the minute they emerge from their crysalis, begin to hunt for two things, a female and a salt lick. The female part is kind of obvious, but the salt lick isn't as well understood. It seems that the male eastern tiger swallowtails who get some salt into their system as soon as they emerge are more successful at the primary job, which is finding a female and persuading her to have his babies.

To get the salt, the butterflies (males only in this case) do something called puddling and you may have stumbled onto it. I've run into several puddling groups. They gather on the ground and suck up salty residue. They clump together, seeming to favor one particular spot on the road, presumably the saltiest, on which to feed. I took this video of them puddling near the Clark Pond boat launch.

Eastern Tiger Swallowtails puddling near the Clark Pond boat launch.

Their heads are up near where the stripes begin. I mention this because the more I watched the video, the more clear the advantage of those false eye spots on the tails. Their tails look more like heads than their heads do!

Bonus Bug

I just love this guy. He (or she) is a clavate tortoise beetle. He's miniscule and looks very much like bird poop, which I imagine is a good way not to get eaten. People seem to like this beetle because from a certain angle, their wing coverings look like a teddy bear. I didn't find that angle. Instead I found the cutest pair of tiny feet I ever saw. So now you get to see them, too.