The Nature of Delaware

By Jim White: Associate Director, Land and Biodiversity

I have been putting off writing this blog entry for about a month. In fact I still am not sure that the following story is “blog worthy” but what the heck – here goes…

It was a beautiful sunny day and I was taking a blissful ride on my motorbike. As I cruised down Brackenville Road I was surprised when I was struck by an insect on the side of my face. Actually, insect strikes are a fairly common occurrence and this one didn’t feel that bad because I was only going 25 mph. However, instead of bouncing off my face as I expected, this bug crawled under my helmet and then into my right ear. I couldn’t stop immediately, but I was close to the Ashland Nature Center and decided to pull in and assess my situation. As I pulled up the driveway I saw Joe Sebastiani walking toward me. Much to his dismay I asked Joe to look into my ear to see if he could see the intruder. Joe made a feeble attempt and informed me he saw nothing.
So I went to my desk figuring that the little creature would soon decide to crawl out and go about its business. But after twenty minutes of trying to identify the bug just by feeling its little legs scratching annoyingly deep inside my ear, I decided to go home and lay down and let gravity assist in the exit. Once I was lying down I had plenty of time to ponder my situation. I started to recall an episode from one of my favorite TV shows of my youth: Rod Sterling’s “Night Gallery”. Some of you might remember the episode erroneously called “The Caterpillar”. The unlucky protagonist has a small insect-like creature (which they call an “earwig”), crawl into his ear. The creature then burrows through his ear and into his brain, causing a slow slide into insanity. Well, just when I was amusing myself with the coincidence, my intruder started to move with more vigor and instead of crawling out it decided to go deeper, finally crawling on my ear drum. This is when I started to think that maybe there was some truth to the TV story.
Luckily, after several very painful minutes, my ento-friend finally decided to make for the daylight and crawl out of my ear. Not only was I relieved physically, I was also finally able to identify the creature. It was not an “earwig” but instead an almost inch-long Rove Beetle (family Staphylinidae). Well, for me that explained why the creature had crawled into my ear canal instead of just flying away. Rove Beetles have a natural ability and affinity to crawl into tight places: they typically are found in and under dead animals where they feed on fly maggots, and they enter carcasses through openings in the skin. As I believe there were no maggots in my ear for it to feed on, I would guess that my visitor was “glad’ to be free. I know I was sure glad to see him go.

Happily, I have suffered no lasting ill effects from the experience, but if you recall the end of the TV story — only time will tell. You see, in the TV story, although the invading insect was removed, it was discovered that it was a female and had laid eggs in the poor fellow’s brain. Do-do-do-doo, Do-do-do-doo! 

Simulation by Gregory White

Rove Beetle

By Jim White, Associate Director, Land and Biodiversity

I have always enjoyed answering questions about wildlife and take a bit of pride in being able to come up with answers quickly. However, every now and then there are questions that are real stumpers. These questions are always the most fun to work on and often require communication with other naturalists, flipping through old field guides, and of course searching the web.

One such question turned up the other day. A friend of mine called me when he and a few of his neighbors discovered an interesting scene on the neighborhood sidewalk. My friend described it as several groups of worm-like things forming a rope and walking en masse in a clockwise circle. The ropes were several “worms” thick and joined head to tail. He was speculating (in jest) that they were an alien life form. To be honest I was wondering if he might be right. Luckily, one of the neighbors, Paul Dreyfus had a digital camera and was able to take a few photos and send them to me. I waited in anticipation, figuring that once I saw the photos I would know exactly what the “worms” were. But noooooo! Although I could tell that they were insect larva I had no idea what kind.

Strange insect larvae walking in a circle on a sidewalk. Photo by Paul Dreyfus.

I decided to ask Richard Smith a well-versed entomologist that I know. He was also stumped but did some web searching of his own and found our answer in a photo on an obscure garden listserve. Sure enough the photo was a match – the “aliens” were the larvae of a species of Dark-winged Fungus Gnats (family Sciaridae). As their common name implies, the larvae of these small flies (order Diptera) feed on fungus, but they also eat the root hairs of many plants. Some species are known pests of mushroom cultivation and greenhouse operations.

Dark-winged Fungus Gnats close-up. Photo by Paul Dreyfus.

So with the identification in hand I set out to find out all I could about these intriguing insects. I figured a few minutes on the web would give me as much information as I wanted on the little guys. Wrong again. So far I have only found out the following:
• The larvae often live in large congregations and from time to time move en masse to new locations.
• In Europe there are several species of Dark-winged Fungus Gnats, especially the army worm Sciara militaris, that migrate in processions up to ten meters long, containing thousands of individuals.
• The circles apparently form when the leading larvae mistakenly hooks up with the larvae at the tail of the “rope”, forming an endless loop.
Many questions remain about why and where the larval migrations occur and how frequently the circles form. I will keep searching for these answers and report my findings (if any) in another blog. Meanwhile, please contact me if you’ve seen, or have additional information about, these “alien worm circles”.

Finding or observing a rare or uncommon plant or animal is one of a naturalist’s greatest joys. I for one have spent many hours searching high and low for rare birds, herps, and insects. However, many times rarities turn up when you don’t expect them and sometimes they are found by the unsuspecting.

One such find happened on September 28, 2009 at the Delaware Nature Society’s Burrows Run Preserve in northern Delaware. During the “Life of the Monarch Butterfly” program being taught that morning to students from The Pilot School, one of the children netted a butterfly that looked unusual to the Teacher-Naturalists (TNs) leading the program. One of these TNs, my wife Amy, realized that she had never seen this type of butterfly before and decided to keep it in the collecting jar until she could make a positive identification. Moments after the school group left the preserve, Amy and fellow TN Judi VanderWerff were able to match the butterfly to one in Elton Woodbury’s Butterflies of Delmarva field guide. And sure enough, it was a butterfly very rarely encountered in our area, called a Milbert’s Tortoiseshell Nymphalis milberti. This handsome butterfly is mostly dark on the upperside except for a wide, bright orange band near the outer edge of the wings. It typically ranges well north of Delaware, usually in the mountains, and also in the western U.S.. Considered a stray in the mid-Atlantic region, this individual possibly was blown down from the Appalachian Mountains. This great find brings the total number of butterfly species found at the Burrows Run Preserve to fifty-four. So stay alert and you may just be the one to find the next rare critter in our area!

By Joe Sebastiani, Members Program Team Leader

I know you all must be on the edge of your seats waiting for the answer to the recent butterfly quiz, so here it is.

29 people took the quiz, and the 21 of you that picked Gray Hairstreak are correct.  Let’s review the butterflies in the quiz.

This summer azure lacks a tails on the hindwing. The similar looking Eastern Tailed Blue has tails, and an orange spot on the hindwing.

Two of the choices were the Summer Azure and the Eastern Tailed Blue.  Pictured above is the Summer Azure.  Compared with the Gray Hairstreak below, it has dots instead of lines on the underside, plus it lacks tails.  The similar Eastern Tailed Blue (not pictured) looks like a Summer Azure with tails and a small orange spot on the outer portion of the hindwing.

The answer to the butterfly quiz is the Gray Hairstreak. Note the tails, and an orange spot on the hindwing, combined with lines on the underside, not a row of spots, as in the Summer Azure and Eastern Tailed Blue.

We’ve eliminated the Summer Azure and the Eastern Tailed Blue, but what about the White M Hairstreak?  As you look below, notice that the orange area is set a little more inward from the rear edge of the hindwing.  Also, there is a distinctive white spot inward from the white line.  If you look closely, you can see a white “M” or “W” inward from the orange spot.  Lots of other hairstreaks have a feature that is similar, so it usually isn’t a good identifying field mark, even though this butterfly is named after it. 

This White M Hairstreak has a white spot in the central part of the underside. Also, the orange spot is set more inward from the rear edge of the hindwing than that of the Gray Hairstreak.

The White M Hairstreak is rather uncommon in Delaware, whereas the other three butterflies in the quiz are very common.  This is a great time of year to observe butterflies nectaring on wildflowers in meadows.  Ashland Nature Center has a meadow across the covered bridge from the center where you can look for lots of butterflies, dragonflies, and many other intersting insects among the blooming wildflowers.  Photos by Joe Sebastiani.

 By Joe Sebastiani:  Members Program Team Leader

Do you want to become a better naturalist?  Here is a butterfly multiple choice quiz question that will require a butterfly book or looking on the web for the species below.  Do a little research and vote on what kind of butterfly you think this is.  The answer will be posted soon.  If you have any questions, be sure to leave a comment on this post.

What kind of butterfly is this? Photo by Joe Sebastiani

By Joe Sebastiani, Members Program Team Leader

At this time of year, insects are abundant and easy to find and photograph.  Last week I tried recording insects on video at Ashland Nature Center and the Bucktoe Creek Preserve.  Most of the videos have the constant buzzing of Silver-bellied Cicada in the background, which is the sound of late summer here in Delaware.  Insects are feeding on native plants, and in turn feed birds heading south.  Since Black Walnuts are full of insects, these are my favorite trees to watch for migratory songbirds.  The flow of energy from the sun to walnut tree to caterpillar to warbler is easy to see these days.  Get outside to witness these natural connections yourself as migratory songbirds stop in our area between now and late October.

The odd and somewhat creepy Butternut Woollyworm was found on a Black Walnut, which is one of their favorite foodplants.  This insect looks like a caterpillar, but is actually the larva of a sawfly, Eriocampa juglandis.  Sawflies are related to wasps, but their larva look like moth or butterfly caterpillars.  As you watch the Common Whitetail dragonfly, look at the abdomen flexing in and out, which is how insects breathe.  The Ebony Jewelwing damselfly and the fly in the following segment are eating very small insects.  Skippers are tough to identify, and I am mostly sure this is a Zabulon Skipper.  If you are a skipper expert, let me know if I am wrong and what kind of skipper this is.  Finally, enjoy the fall-plumage Chestnut-sided Warbler feasting on a caterpillar.