Imperial Moths and Caterpillars

Recently I told you about our experience with gypsy moths. After that batch of destructive caterpillars made their presence known on our cottage lot, we discovered another caterpillar, this one quite striking.

It was huge, over three inches in length and one half an inch in diameter. It was bright green in colour, with white spots and bristles. Google claims this caterpillar belongs to the Imperial Moth, and Wikipedia claims it is not found much further north than the New England states. That explains why we have never seen one before. I guess this guy wandered a little too far north.

I have been teaching my grandchildren the wonders of nature. I have no doubt my three year old grandson would love this colourful caterpillar; my granddaughters not so much. It has been much more difficult to convince them that (some) bugs are beautiful and beneficial.

We will keep our eyes out for the Imperial Moth this caterpillar will morph into next spring. It should be easy to spot as they can reach five and a half inches in size!

Hydrangea leaf caterpillars

Hydrangea leaves that look like this contain a grub, a stage of the leaf curl moth.  The moths lay their eggs on the leaf then spin a fine silk like web around the eggs to attach them to the leaf.  The silk threads cause the leaf to curl protecting the eggs from predators like birds.  The eggs hatch into caterpillars that eat the leaf and soon become adult moths, continuing the cycle.

Moths prefer leaves of lilac trees due to their softer texture, but if a hydrangea is next to a lilac, the moths will lay their eggs on hydrangea leaves too.  As soon as you see the leaves curled on either lilac or hydrangea bushes or trees, remove the leaves and burn, crush or shred them to kill the eggs.

I saw some of these on hydrangea leaves last summer.  I tried to kill the worms and eggs by spraying with tea tree oil, but it did not seem to work.  I then cut off the infected leaves, which seemed to help.