Edwards' Hairstreak Butterfly Census 2018

Since I don’t actually count the butterflies or produce any type of tally, my annual observations of the Edwards’ Hairstreak Butterfly can’t really be called a census.  What I do is search appropriate habitat at Blue Jay Barrens to get an idea of current size and distribution of this uncommon butterfly.

Each year, I find butterflies in new locations and in concentrations larger than the year before.

Edwards’ Hairstreak Butterflies were quite rare when I first surveyed this property 33 years ago.  It took years before I found my first specimen.  Subsequent annual searches resulted in sightings of just a few individuals or, in some years, no sightings at all.  Now I can find that many or more sharing a single flower cluster.

One of my first management projects was to make the property more suitable to Edwards’ Hairstreaks.  I cleared Eastern Red Cedar from the fields to promote prairie like habitat, and encouraged the growth of Blackjack Oak, the Edwards’ Hairstreak preferred larval food. 

As habitat improved, the number of butterflies increased.  Nectar plants also responded to the management efforts and increased in number.  Butterfly Weed, a favorite of the hairstreaks, is now common in most areas containing butterfly colonies.

A few years ago it was uncommon to see more than a single Edwards’ Hairstreak on a clump of Butterfly Weed flowers.  Now the butterflies visit the blooms in masses.  There are 10 butterflies clearly visible nectaring on Butterfly Weed in the above photo.  There are still suitable areas not yet being utilized by the butterflies, so butterfly numbers have the potential to increase for many years yet.

The above video shows some Edwards’ Hairstreak nectaring action.  A few Honeybees are also trying grab some of the nectar.  Near the end of the video, one butterfly appears to headbutt another away from his flower cluster.  This video can be viewed on YouTube by clicking HERE.

Squash Vine Borer Moth

In my vegetable garden, I have a large clump of Butterfly Weed that brings in a wonderful collection of nectar consuming insects.  I had my face tucked in close to the bright orange blooms when a wasp-like insect nearly grazed the tip of my nose.

I pulled my face back a bit and watched the little flier spiral its way into a landing on one of the flower clusters.  At rest, this insect certainly displayed some hymenopteran qualities, but it was certainly no wasp.

Closer examination shows it to be a moth, a Squash Vine Borer Moth to be exact.  This is one of the few day flying moths.  It is also a wasp mimic, meaning that the physical appearance of the moth has a resemblance to a wasp.  This mimicry affords the moth some protection from predators that would avoid tangling with a stinging wasp.

A search of the flowers revealed several of the moths mixed in with the crowd of truly stinging insects.

The hind wings are clear, which emphasizes the dark forewings.  When outstretched, the wings resemble the raised forewings of an angry wasp.  The hind legs bear large tufts of dark reddish-orange hairs.  When in flight, the moth carries the legs below the body and it looks very much like a wasp carrying a caterpillar.

The antennae with their curled tips even look like the antennae of male polistes wasps.  This is a very interesting moth in terms of both form and behavior.  The name Squash Vine Borer says all that most people need to know about this moth.  The larvae live their lives inside the stems of squash vines and their relatives, ultimately bringing death to the plants.  Because of this, most people’s interest in the moth doesn’t stray far from how it can be eliminated.

There’s a good reason why so many of these moths were visiting this particular patch of Butterfly Weed.  There are some nice summer squash vines growing just a few feet away.  I may lose a vine or two to the moths, but it’s not really a hardship.  I’ll trade a couple of vines for the experience of watching the adult moths.  Besides, I love to eat fresh squash and start a few new plants every couple of weeks right into summer.  The adult moths are only around for a short time, so they won’t infest my later plantings.  I’ve never had them lay eggs on all of my vines and there has never been a summer when I couldn’t go out at any time and pick some fresh squash.

Unexpected Tiger Moth Larvae

The blooms of my favorite milkweed are quickly fading from the prairie landscape.  Spider Milkweed, Asclepias viridis, is an early season bloomer that generally ends its flowering period before the first day of summer.  Not only does this plant produce an amazingly interesting flower, it also is a focus of activity for a variety of animal species.  It’s impossible to look closely at these flowers without some small creature looking back.

The pale green flowers are impossible to miss.  If Spider Milkweed is in the mix, it will certainly be noticed. 

Having a multitude of insect visitors means a quick pollination.  Seed pods soon replace flowers.  By mid summer, seeds will fly and the plant will begin to enter its dormancy.

Among its many insect visitors, Spider Milkweed supports the larvae of the state endangered Unexpected Tiger Moth, Cycnia inopinatus.  The orange bodied larvae are easy to see against the green of the plant.

The Unexpected Tiger Moth is double brooded in southern Ohio and is generally associated with Butterfly Weed, Asclepias tuberosa.  The body color of the larva tends to blend with the orange flowers of the Butterfly Weed and provide some protective camouflage.  That strategy doesn’t work on the Spider Milkweed.  Many insect species that feed on milkweed develop toxicity by consuming and processing the toxic compounds in the plant.  Orange coloration is a common trait shared by these insects and indicates to predators that the insect is best left alone.  That may help this colorful larva to avoid predation.

I assume that the adult moth lays its eggs on the flower buds of the Spider Milkweed.  Signs of feeding on the flowers is the first clue that Unexpected Tiger Moth larvae are on the plant.  As the larvae grow, they move on to feed on the leaves.

During the last few years, I have noticed that the first brood of the Unexpected Tiger Moth utilizes Spider Milkweed and the second brood uses Butterfly Weed. That means it is necessary to have an adequate population of both milkweed species in order to have a healthy population of moths.  Currently at Blue Jay Barrens, Butterfly Weed is much more common than Spider Milkweed and the two species grow in different areas.  I am now attempting to establish Spider Milkweed populations in closer proximity to the Butterfly Weed to see if this increases the numbers of Unexpected Tiger Moths. 

Part of that activity will take place in my garden where this clump of Butterfly Weed has a history of hosting second brood Unexpected Tiger Moths.  It takes two or three years for a Spider Milkweed plant to reach flowering stage, so it will be a while before I know if my plan is successful.  I’m hopeful that I will eventually see this effort benefit the moth.  Even if it doesn’t, it will be nice to have more Spider Milkweeds growing in the fields.

Saturday Color

It was suggested to me that I should not leave the picture of a Multiflora Rose thicket all weekend as the first thing people see when they visit the site. I was told that the rose photo looked like any old tangle of briers and I agreed that it did look that way, if the tangle was one of Multiflora Rose. So, here’s a bit of color for your Saturday morning. This is Butterfly Weed. It and many other flowers are just starting to bloom here. I’ll get out in the prairie and share some of the blooming plants with you next week. For those who prefer insects to flowers, there’s a blurry Milkweed Bug between the two flower clusters.

If you like a little music in the morning, I give you Catbird on a wire. I was serenaded the entire time I was photographing the Butterfly Weed. This is one of those silhouette shots. The background color is the true color of the sky this morning. Things keep getting darker instead of lighter and there’s a very strong breeze. The Catbird’s wire was bouncing up and down and I had to sway along with the Butterfly Weed to get a shot even close to being focused.