This evening I was accompanied by the rest of the Wagner lab on a night visit to Blue Hills to sample oaks for larvae as we did last year and also to do some moth collecting. We arrived around 7PM and were greeted by a fabulous sunset. As the colorful horizon began to dim, we went to work setting up a white sheet and MV light to draw in moths and it wasn’t too long before we had our first visitors. This collecting activity was unrelated to the Oak Hairstreak study but intended more for other lab research projects and also to observe and enjoy the lepidopteran diversity of this interesting monadnock of the Blue Hills Reservation. It was a very productive night for moths, but I only took a few pictures.
The Peppered Moth (Biston betularia)
The Yellowhorn (Colocasia flavicornis)
Azaela Sphinx (Darapsa choerilus)
Rosy Maple Moth (Dryocampa rubicunda)
Abbott’s Sphinx (Sphecodina abbottii)
As for caterpillar collecting, there was an equally diverse bounty. We focused mainly on scrub oak (Quercus ilicifolia) and white oak (Quercus alba) where accessible. We encountered at least 20 species, and collected a few of interest; Glaea, sp., Catocala sp., Eupsilia sp., Phoberia orthosioides, Meganola spodia, Speranza exornata (a state-listed geometrid) and two Satyrium species. The first of these hairstreak larvae was a single Banded Hairstreak (Satyrium calanus), and the other 18 we encountered were all Edward’s Hairstreaks (Satyrium edwardsii). Just like last year, these caterpillars were reliably found by beating scrub oak along the trail. All were tended by 4-7 ants and some individuals were quite large. The most satisfying way to track down these caterpillars is to look for a stand of scrub oak crawling with ants and follow them to the hairstreak. I found a good number of them this way, but getting a decent photo in the field is another story. The nocturnal creatures are quite negatively phototactic and so when discovered under the light of a head lamp, they begin to slink away before you can get too many good focused images. Thanks to my labmate, I have a few to share though.
Edward’s Hairstreak larva tended by 5 ants.
In searching for these caterpillars on scrub oak, it was hard not to notice the immense amounts of damage to many of the plants. The culprits behind this oak ravaging are winter moth caterpillars (Operophthera brumata) of which we saw >500 and the Fall Cankerworm (Alsophila pometaria) of which we saw >100 individuals.
Oak Hairstreak Study 