May 15: Burlap banding

We set up the burlap more than two weeks earlier than last year, and I’m quite hopeful it will pay off. Our efforts last spring showed that this is a successful method for sampling oak-feeding hairstreak larvae (see posts from June 1 and June 5). Again, our target was about 150 total trees, all white and red oaks of varying ages/diameters. With two teams of two, we were able to band nearly that many in under 3 hours. The banded trees will be counted and flagged with numbered orange tape tomorrow.

Dave and Katie banding a white oak with burlap.

Kevin slitting the burlap to create three easily liftable flaps per tree.

As we tromped through the underbrush, we saw the many tent caterpillars (Malacosoma americana) lazily emerging from their silken strongholds to ravage the cherry trees they were laid on. I also saw about 10 Pine Elfins (Callophrys niphon), 3 Tiger Swallowtails (Papilio glaucus), 2 Black Swallowtails (Papilio polynexes), a good number of Juvenal’s Duskywings (Erynnis juvenalis), 3 Garter snakes (Thamnophis sirtalis) and Kevin chanced upon a late instar Red-spotted Purple larva (Limenitis arthemis) feeding on scrub oak. The most unusual find of the day was a sleek black spider with bright red markings on its abdomen. Could it be?! Yes, a black widow! A Northern Black Widow (Latrodectus variolus) we believe. Not as deadly as its famed and feared southern counterpart (Latrodectus mactans), but still capable of an unpleasant bite. One good reason to watch your step if you venture off the trails.

A cluster of Easter tent caterpillars (Malacosoma americana) feeding on black cherry (Prunus serotina).

Eastern Pine Elfin (Callophrys niphon)

Late instar Red-spotted Purple larva (Limenitis arthemis) feeding on scrub oak (Quercus ilicifolia).

Female Northern Black Widow (Latrodectus variolus).

June 4, 2013: More Banding and Caterpillars

Today we banded about 30 more white oaks along trail 1045 towards the observatory and numbered each of our 148 banded trees with white plat tags. Since the banding efforts have only produced one nearly pre-pupal Satyrium larva, and not the species of interest we fear we may have missed the window of opportunity for collecting Oak Hairstreak caterpillars in this fashion. Nevertheless, we will continue checking throughout the season and document what turns up. More data never hurts.

As we checked the bands today, we collected any species that we we’re unfamiliar with for identification and release later. Based on the positive IDs, I put together a basic guide to the Lepidopteran fauna you may encounter under burlap bands in the area. I will keep it updated with other species we find.

Caterpillar species under burlap at Blue Hills

May 30, 2013: Burlap Banding

Minor issues with permit processing held our site access and start date back a few days, but nonetheless we headed into the field today. Two teams of two banded about 120 red and white oaks. This method of caterpillar collecting is a simple procedure where a strip of burlap about 15-20cm wide is wrapped around the trunk of a tree at chest height, stapled in place, and slit 2-3 times to form liftable flaps. It’s a sort of “set it, and forget it” method that is very effective in sampling larvae that descend trees to rest on bark during the day. It is the primary survey technique forest managers employ to census populations of Gypsy Moth (Lymantria dispar) caterpillars, which I predict we will encounter ore than our fair share of here.

Banding a white oak tree with burlap

Our subjects of interest, Oak Hairstreak larvae, are expected to travel down their host trees to pupate in leaf litter. The aim of the burlap in this case is to deceive the larvae into thinking they have fully descended and have found a nice dark place to pupate at the base of the tree.