June 12: Burlap Removal: Day 2

I have been meticulous in the removal of burlap and staples from all trees that we set them on, and so I required two full days to take everything down. If you are up at Blue Hills and notice a band that I missed, please let me know. Just like yesterday, I found more Satyrium pupae among the vast amounts of Gypsy Moth and other caterpillars. I found 2 on one tree and a third on a different tree. Both were relatively young trees and ones that I had not yet collected from. Interestingly, the pair that I found on one tree were tucked under the upper margin of the burlap skirt where I would not have seen them during a normal check. It’s totally possible I could have missed some pupae last year because of this or even because the descending prepupae tucked themselves under the bark of the white oaks. I always kept this in mind when checking, but it is impossible to see under every scrap of bark.

A Satyrium pupa under the first burlap band I checked today. This one was on a relatively young tree.

Two pupa tucked under the upper margin of the burlap skirt.

Note the different coloration and size of these two pupae. One may have pupated more recently or it may be a different species.

Despite the butterfly that emerged in our lab, I think it is too early to look for adults since the caterpillars are still pupating and nectaring sources have not yet begun to bloom. The Yarrow (Achillea millefolium) is up but without flowers yet, and the milkweed has a ways to go. I will return in a few days to see how things are progressing.

Yarrow (Achillea millifolium) nearly in bloom.

Here is a tally of caterpillars species I saw while removing the burlap over the past two days on Red and White oaks. Red Oak: Dasychira obliquata (5), Glaea sp (2), Hypoprepia sp. (2), Lithophane sp. (2), Lymantria dispar (51), Malacosoma americana (3), Malacosoma disstria (10), Malacosoma cocoons (1), Orthosia hibisci (1), Orthosia rubescens (3), Phoberia atomaris (7), Satyrium ?calanus (1). White Oak: Catocala ilia (1), Catocala sp. (1), Dasychira obliquata (8), Glaea sp (5), Hypoprepia sp. (8), Lithophane sp. (1), Lymantria dispar (60), Malacosoma americana (18), Malacosoma disstria (17), Malacosoma cocoons (10), Orthosia hibisci (3), Orthosia rubescens (13), Phigalia titea (1), Phoberia atomaris (18), Satyrium ?ontario favonius (4).

June 11: Burlap Removal: Day 1

Urged by today’s successful Oak Hairstreak emergence, I began removing the burlap from all the trees that we’re used in this part of study. I’ve collected 2-3 Oak Hairstreak prepupae thus far which supports the claim that white oak (Quercus alba) is the preferred host in the northern extent of the species’ range. The positive results of the larval sampling efforts this year show how effective burlap banding can be for collecting Oak Hairstreak caterpillars as they descend their hosts to pupate in the leaf litter. Looking back to last year’s results, it seems an early start makes all the difference. Once the gypsy moth, Quaker, and Oak moth caterpillars start to take over (as they are now), the window of opportunity to collect Satyrium caterpillars has closed. This is a good signal to end larval sampling efforts.

In the process of removing the bands, I collected two Satyrium pupae attached to the burlap on two different white oak trees that I hadn’t yet collected hairstreaks from. At this life cycle stage, it is very difficult to differentiate an Oak Hairstreak from a Banded, so I collected these only to get a verifiable identification when they adult emerges. These and any other hairstreaks collected from this point on will only be contained long enough to obtain an identification.

The first Satyrium pupa I collected today. I found it attached to the burlap on a white oak tree.

A close-up of Satyrium pupa #1.

The second Satyrium pupa I collected. Note the cast skin of the final instar larva below this one.