The remarkable diversity of bugs in the garden
Although we try to highlight the wide array of species of all types in the garden, it is always fun to come back to the Lepidoptera. Today we look at two caterpillars and two moths that were seen this year at Thuya Garden. The first is one of the most colorful caterpillars in the garden, that of brown-hooded owlet moth, Cucullia convexipennis. This caterpillar primarily feeds on asters (various genera) and goldenrod (Solidago); this one was munching on aster in the butterfly garden. Less showy but no less interesting is this all green caterpillar, that of the yellow-shouldered slug moth, Lithacodes fasciola. We were lucky to have seen it, as it is well camouflaged in the vegetation. They feed on a variety of woody plants; this one was found on a small mountain ash tree (Sorbus).
Of course, adult moths have their own appeal. One of the new species of moth we saw this year was this from the genus Symmerista. These are difficult to identify to species, especially from a photograph, but I suspect it is Symmerista leucitys, the orange-humped mapleworm moth. The other Symmerista species in our area are known as oakworm moths. As the name implies, these prefer oaks as caterpillar host plants. At Thuya we have an abundance of maples, but only one oak, so odds are we would more likely get the species that likes maples. Another new moth was this small one from the genus Tebenna, also notoriously difficult to identify to species. These small moths are in the family Choreutidae, the metalmark moths. The name refers to the reflective spots or patches on the moth wings. It is difficult to find more information on these moths; even the caterpillar host plants for many species are unknown.
As of this writing (mid-November), we are finally getting some chilly weather. We normally associate insect activity with the height of summer, but there are often things still about in the fall, some of which were not apparent earlier in the year. Late summer and fall often see the arrival of the autumn meadowhawk (Sympetrum vicinum), a small species of dragonfly that can occur in Maine well into November. This one decided to land on my knee in late September. Like nearly all dragonflies, they are predators both as larvae and as adults. Good to have around, adult dragonflies of any sort feed on flying insects, including many we call pests.
The western conifer seed bug (Leptoglossus occidentalis) is about 1/2-3/4 inch and can sometimes be seen late in the season, even into December. As the name implies, its origin is in western North America, but has been expanding its range eastward since the 1950s. They are a member of the family Coreidae, the leaf-footed bugs. This name makes sense when one notices the enlarged tibial area on the hind legs. These late season sightings are usually individuals looking for shelter for the winter, often ending up in buildings. Though they can emit a stink when harassed, they are generally harmless toward people (and buildings).
A pleasant surprise this year at Thuya was a number of the attractive caterpillars of Haploa moths seen at the lower pavilion bed into at least mid-October. This type of moth overwinters as larvae, and these were getting some late season eating done before settling in. Sightings in Maine can even occur in December. This genus of moth can be difficult to identify to species as caterpillars, but relatively easy to identify as adults, which have bold wing patterns. We have seen adult moths of Leconte's haploa (Haploa lecontei), the two photos showing some of the variation in this species. These kinds of sighting can serve as a reminder that even when we may consider our gardens as being "done" for the season, there may be some wildlife still trying to make a living. Let's not be too eager to cut back or tear out all the plants.