Location, Location, Location

While carefully pruning our fuchsia-flowered gooseberry today, keeping a careful eye on the ever-present and incredibly sharp thorns, I came across this little branch with an unusual swelling.

It was a tent caterpillar's egg case, and inside were 100 to as many as 400 tiny caterpillars, waiting patiently for spring.

Prior to the sizable infestation of western tent caterpillars that our region experienced a few months ago, I wouldn't have known what this odd, wrap-around, gray-brown, slightly shiny swelling was. Measuring about half an inch (0.75cm), the egg case is created from a frothy material called spumaline, which the female caterpillar exudes after mating and depositing her fertilized eggs. Spumaline repels water, preventing the eggs from drying out; its hard exterior also protects them from cold winter weather.

The eggs begin to develop into tent caterpillars shortly after being deposited. In three weeks or so, each egg holds a tiny, fully formed caterpillar that will hatch the following spring, just as the leaves of their host trees are opening.

The inhabitants of these eggs will not be among them, however, despite their mother's careful placement of her egg case deep in the branches of a thorn-covered bush.

There might, however, be another before breakfast scientific investigation in the next week or two...