May 27: Oak Hairstreak at last!

Oak Hairstreak prepupa (Satyrium favonius ontario)

First and foremost, ladies and gentlemen….the oak hairstreak!!!! The fruit of my burlap-flipping labor presented itself today in the form of a stout green prepupa attached to the burlap flap on a mature white oak tree near the stone lookout tower. To differentiate from other hairstreak larvae I have encountered in the area, this species has a dark dorsal heartline and is covered with small white speckles that appear to be setal bases though the only obvious setae are the fringe setae around the outside edges of its body. Finding this caterpillar both verifies white oak (Quercus alba) as the host plant for this hairstreak and demonstrates the efficacy of burlap band larval sampling. Just as we had theorized, we captured a prepupal caterpillar that was heading to the duff at the base of the tree to pupate. I could easily tell it was prepupal because it was developing a rosy tinge to its posterior edge. I carefully collected this specimen from the burlap and put it in a container with proper substrate to pupate in. Through prior research on the Oak Hairstreak, I am quite confident this is the larva, but it must be reared to adulthood to make a proper identification. When it emerges, this single butterfly will be saved as a voucher specimen for this project and used to do any DNA work. I am incomprehensibly excited and relieved to have found this caterpillar, but also surprised at how far it was from the slope.

In checking all the other burlap skirts, I found one new species, Lytrosis unitaria, a large geometrid. On another band, I found a large cluster of Forest Tent caterpillars in a group molt. They formed a very conspicuous, fuzzy lump on the tree. As I walked through the woods, I noticed a nigh number of Dasychira obliquata caterpillars as well as green sawflies (Craterocercus sp. or Pristiphora sp.) eating oak. I don’t seem to remember running into so many of these last year.

Lytrosis unitaria under burlap.

 

Molting cluster of Forest tent caterpillars (Malacosoma disstria).

Streaked Tussock Moth (Dasychira obliquata)

Sawfly (Craterocercus sp. or Pristiphora sp.) eating oak

The other species that has reached devastating numbers as we realized during the night visit is the winter moth (Operophthera brumata). Below is the type of damage that these pesky and voracious little caterpillars can do.

May 26: Night Visit

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.

May 20: Juniper and Hessel’s

I walked up the slope today to maximize my collateral nature-viewing opportunities. The milkweed is up at the bottom of the hill, but not flowering yet. As I noticed last year, many of the slopes are covered in Wild Indigo (Baptisia tinctoria) which is the host plant of the Frosted Elfin (Callophrys irus). The larvae can be located by searching for telltale feeding damage. Late instars girdle the stalks of their hostplant possibly to access phloem or circumvent plant defenses, which causes single clusters of the plant to blacken and wilt. I searched for damage and adults as I made my upward trek but saw neither. I imagine they would flourish here with such an ample food source, but I have yet to see one myself.

Wild Indigo (Baptisia tinctoria).

There are more and more winter moth caterpillars (Operophtera brumata) under and about the burlap daily, but no signs of hairstreaks yet. Based on what I’ve seen thus far, I’m steadfast in my confidence that we will get an Oak Hairstreak. There have only been early species under the burlap and very little overlap to what I saw last summer when the first check was on June 1^st. The Oak Hairstreaks must be in this earlier group.

The Winter Moth (Operophtera brumata).

During the larval sampling last year, I didn’t take enough time to simply walk around the reservation and observe the early flying species. This year, I’m making a point of doing more, and as a result I’ve already added another gorgeous lycaenid species to my life list: a Juniper Hairstreak (Callophrys gryneus). I believe it was nectaring at some white flowers when I scared it up. They are beautiful olive-green creatures with bold white marking on wings. I also saw one Gray Hairstreak (Strymon melinus) whose moments of rest were too ephemeral to allow a photograph. It landed on a number of these strange plants that seem to be taking over the summit and the area around the weather observatory – especially the thistle patch! To my dismay I later learned this is the dreaded invasive Black Swallow-wort (Cynanchum louiseae) that is threatening our Monarchs. I’m amazed and disturbed to see how much it has spread since last summer. If you recognize this plant, I would advise and encourage uprooting a few every time you visit the area.

Juniper Hairstreak (Callophrys gryneus)

Black Swallow-wort (Cynanchum louiseae).

A chance find of the day happened while photographing a Spring Azure (Celastrina ladon). I crouched down in the leaf little just off the trail to focus on the butterfly and below me I saw a very still, very camouflaged, and very large serpent. It was a gorgeous adult Eastern Milk Snake (Lampropeltis triangulum triangulum) and had I knelt down completely, I would have been right on top of it. My herpetologist heart insisted that a snake trumps a butterfly, so I snapped one quick shot and switched my focus to the nearly 3 foot long reptile. Surprisingly, I got decent photos of both.

Eastern Milk Snake (Lampropeltis triangulum triangulum)

Spring Azure (Celastrina ladon).

When I reached the bottom of the slope and was just about to leave, I ran into Gary Kessler who informed me that the Hessel’s Hairstreaks (Callophrys hesseli) were on the wing at Ponkapoag Pond. After receiving the treasure-map-ishly specific directions to a dependable group of cedars, I made my way there to walk the intermittently submerging planks of the boardwalk. Branch tapping and patient cedar scanning produced no hairstreaks, but as I was about to go, a small brownish butterfly perched for just a moment on the blueberry bush beside me. I’m afraid my Hessel’s Hairstreak sighting is a photo-less fish story, but I’m pretty sure I saw one.

May 18: Hide or be eaten

Possibly a Painted lichen moth (Hypoprepia fucosa).

I found a familiar little lichen moth caterpillar under a band today, but Dave believes it may be a different species that what I am used to. Last year I mainly found Scarlet-winged lichen moths (Hypoprepia miniata), but this specimen may be a Painted lichen moth (Hypoprepia fucosa). I collected one to rear so I’ll just have to play the waiting game now. Along with that were more Abagrotis and Haploa as well as a little brown geometrid that has not been identified. There have been a number of interesting adult moths resting on or hiding under the burlap too.

Unknown brown geometrid

A Raspberry Bud dagger moth (Acronicta increta)

A Curve-lined Angle (Digrammia continuata).

On my way down the slope, a particularly docile Duskywing offered me a good opportunity to practice close up shots of live lepidoptera with a Raynox macro lens attachment that I’ve acquired since last summer. I got some great pictures and when finally I became too prodding, the skipper took off, but it did something I’ve never seen one do before. Instead of erratically zipping away, it flew up above me to land upside down on a thin tree branch. It then relaxed its wings wrapping them around the branch making the animal blend in reasonably well. This behavior appeared very deliberate and from where I stood, it was hard to focus on the skipper any longer.

A final treat as I neared the bottom of the slope was a decent look at an Indigo Bunting (Passerina cyanea) that was foraging in the treetops. To my great delight, it appears to be eating an invasive winter moth caterpillar (Operophtera brumata) in this picture.