Predators on my porch

Late October produced several interesting critters that were obviously looking for juicy meals. The first photo is a wheel bug,

Arilus cristatus

.

The second one was a small spider, much enlarged in the photo. It looked and acted like a crab spider and, when I intercepted it, was closing in on a moth half again its size.

September sightings

I had several interesting visitors to my moth sheet and porch during September. The first was an American Toad that was obviously looking for a meal.

The second one was a wasp with black and white antennae. It's one of the Cratichneumon species that parasitize various insect larvae.

 The third one showed up in considerable numbers this year. I have photos of the same species from 2011, 2012, and 2013. Even so, I haven't been able to pin a specific species label on it. It's a wingless cricket.

Painful garden encounter

For the first time in nearly five years, I have been able to garden again.  It became crucial to create a deer free zone, not an easy task...combining hard work and the cost of fencing.

Naturally, I went a bit crazy, over-planting many crops, including sweet-corn.  In previous years, we always had a small patch of corn, but nothing like this year.  Perhaps it was the larger space given over to corn, perhaps it was related to the different location, higher up our hill and better sunshine exposure.  Or, equally, it could be just serendipity. But the encounter I will soon share, was a new one.

About three weeks ago, as I was happily harvesting a few ears of ripe corn, suddenly a sharp stinging sensation erupted from the back of my hand.  Knowing there had to be a cause, I poked around the plant looking for the culprit, and this is what I discovered: 

Truth be told, I have always wanted to see the saddle-backed caterpillar, just not under these particular circumstances. 

Acharia stimulea

is common, the cat feeding on a wide range of host plants, including corn.  About an inch long, this member of the slug caterpillar family

Limacodidae

has, according to David Wagner in his Caterpillars of Eastern North America, "...the most potent [sting] of any North American caterpillar."

I can testify to that.  In fact, I have found three this year the hard way, the last encounter only about an hour ago.  First aid for caterpillar stings is duct tape.  Just place the tape firmly over the affected area and gently pull away.  It works, sort of. 

Scott Jackson-Ricketts

What moths do at night

Because we see moths at lights or resting quietly somewhere during the day, it's easy to forget that many of them sip nectar just like their butterfly cousins. Here are two that visited my butterfly bushes on August 31.

The first one is Feltia tricosa/subgothica. This moth is either tricosa or subgothica. I'm told on good authority that a researcher can determine which species if the specimen is a male and he or she examines the antennae under sufficient magnification. Therefore an photograph, even a really good one, isn't adequate.

The second moth never stopped beating its wings. I got a focus lock and snapped a pic. The flash, lasting perhaps a thousandth of a second, turned the blur of the wings into something useful for identification. The moth is Allagrapha aerea, one of the Noctuid loopers.

Here's a photo of a resting Alagrapha aerea that I took in September 2012. If you examine the forewing of both moths you can show that they are the same species, but you'll look in vain on the flying moth for the dorsal tuft on the thorax of the resting moth. When it flies, the scales on the thorax lie flat.

Orange-striped Oakworms

This is the wandering season for oakworms. They come down from the trees and look, sometimes at considerable distances from the trees, for places to pupate in the ground. My wife found one and later I found two more on the back porch. Here's the caterpillar.

The species designation is Anisota peigleri/senatoria because the two are essentially indistinguishable as caterpillars and as adults. A. senatoria is the widespread species. A. peigleri is found in the southern Appalachians. Here's the moth.

Dragonfly Migration at Rocky Knob

Watching dragonflies as they fly southward across the pasture at Rocky Knob is for me the favorite part of the fall migration watch. I enjoy the flights of hawks, and swifts and swallows, and butterflies too. Perhaps a close 2nd to the dragonflies are the hummingbirds.

Many years ago it didn't occur to me that dragonflies migrated. I had heard of them swarming in large numbers, but had never seen that behavior until September 13, 1992. On that day at the Rocky Knob pasture, I saw several hundred per minute, and all of them were heading south. There were dragonflies across the entire field, and as high up as I could see with binoculars. After a while I began to realize that these were not swarming the way I thought of a swarm. First, I didn't witness any of them veering to catch some small insect. And second, I wasn't being attacked by gnats. As a wild guess, I believe that the minimum number of dragonflies I saw was about 250,000. I might have seen many more than that. That September afternoon is still the day, by far, with the greatest tally of dragonflies that I have seen.

I decided that day to learn what some of the dragonflies were, but it took me several years to be able to identify several species on the wing.

This photo is of Common Green Darner, the most abundant and frequently seen migrant most days at Rocky Knob. The species has been recorded at many of the hawk migration watch sites, and has been noted at the hawk site at Veracruz, Mexico in the many hundreds of thousands. Photo 

© Bruce Grimes

These are the most common species seen at Rocky Knob (listed in order of abundance):

Common Green Darner (Anax junius)

Black Saddlebags (Tramea lacerata)

Wandering Glider (Pantala flavescens)

Twelve-spotted Skimmer (Libellula pulchella)

Spot-winged Glider (Pantala hymenaea)

Black Saddlebags, number two in number at Rocky Knob, and it is quite easy to i.d. on the wing.

Photo 

© Bruce Grimes

In general these five species are quite easy to identify on the wing, though spot-winged takes a little more observing to be sure of the species. Observers at Rocky Knob have had a few days with over 10 to 20 thousand dragonflies. Green Darners and Black Saddlebags are the species most likely to be seen in the thousands at Rocky Knob. Numbers in the hundreds have only happened a couple of times, locally, for Wandering Glider, and a couple of times for Twelve-spots.

Twelve-spotted Skimmer. I think this species is my favorite dragonfly to watch in flight. The patches of white in the four wings can sometimes give a sort of "strobe light" effect. It really is dazzling when I catch sight of one while I am scanning the area with my binoculars. Photo 

© Bruce Grimes

The migration for Spot-winged Gliders occurs earlier in the season than we usually cover at Rocky Knob. But if you go there in July you may see several Spot-wings heading south, and maybe not many other dragonflies. The others reach peak movement usually sometime in August to mid to late September.

Spot-winged Glider is an early migrant at Rocky Knob, often showing up in some numbers in July. Note the spots in the wing are small patches close to the body. This species of rain pool glider dragonfly has a darker brown body than does the Wandering Glider which appears much more yellow or sometimes a bit golden on the wing. Photo 

© Bruce Grimes

Spot-winged and Wandering Gliders are two species you might encounter in parking lots. You might even get to see them lay eggs on your car windshield, a behavior that seems much more than wacky. If you ponder it you might conclude that this egg-laying practice is some sort of exercise is futility, with no chance of the eggs hatching. So why do female Spot-winged and Wandering Gliders do this?

I think I will leave the answer for later, and would encourage readers to reply, with their guesses as to why the egg-laying on cars. Better yet, I wish to encourage you to share your sightings of these two species, and the behaviors you observe. You can just reply to this blog posting after you have seen either of these species.

Wandering Gliders, by the way, have one of the widest natural distributions, world-wide, of any insect. They occur on Easter Island for instance. They also are documented as having the longest distance inter-generational migration. Think Monarch butterfly, and add a lot more miles, and make the flight over the Indian Ocean.  Photo 

© Bruce Grimes

Here is a link to a Ted Talk about Wandering Glider migration (note that the dragonfly is referred to as a globe skimmer, actually a most apt name:

http://blog.ted.com/2009/12/17/discovering_dra/

Several other species of dragonfly have also been observed at Rocky Knob. I believe that most of these were migrating, but am not completely certain that all of them were.

Here is a list of these species.

Shadow Darner(Aeshna umbrosa). Note: members of this genus can be difficult to distinguish in flight, so we could have had more than one species occur at the migration watch site.

Comet Darner(Anax longipes). This species isn't noted as a migrant but we have a couple of records--individuals flying through the pasture when there were fair numbers of green darners on the move. We have been wide-eyed in surprise when we see one.

Swamp Darner(Epiaeschna heros). This species is more of a Atlantic coastal region migrant. We have only a smidgeon of records from the pasture.

Emerald species. Not identified to species at Rocky Knob. Our best guess is Clamp-tipped Emerald (Somatochlora tenebrosa). This species is not noted as migratory either. Maybe the few we saw weren't migrants. But they did head south, up and over the trees at the south end of the pasture. At a couple of other locations Bruce Grimes and I have found this species, and been able to identify. At one mountain in Greene County, Tennessee, Clamp-tipped Emeralds were definitely "in the mix" of migrants along with Common Green Darners, Black Saddlebags, Twelve-spots, a few Wandering Gliders, and as I recall, a Swamp Darner or two.

Eastern Pondhawk(Erythemis simplicicolis) We have several sightings of this species flying low, often just above the grasses, all flying generally southward. A few were mature males with bright blue bodies, and some were immature males or females.

Slaty Skimmer(Libellula incesta). Just a few records. Migrants? They flew south.

Great Blue Skimmer(Libellula vibrans). A couple of sightings. The individuals we have identified on the wing, actually perched for a little while so we could figure out what they were, then they flew on southward. Not sure if this species is really all that migratory or not.

Common Whitetail(Plathemis lydia). Generally not listed as a migrant. We have seen a few that flew southward as if migrating. Of course we aren't sure, more observations needed at RK and at other locations. This species is very common throughout the region.

Variegated Meadowhawk(Sympetrum ambiguum). Three sightings. I am still digging through the data pile to find the exact dates. This is one of the most common migratory dragonflies in the western US, but it is more like a waif in our area (as far as we know). The individuals at Rocky Knob were either females or immature males.

Variegated Meadowhawk was a surprise find at Rocky Knob because this small dragonfly is mainly found in the western states. We have no photo from our watch site, so no proof....just a sight record, but hey we know what we saw!  This picture is of an adult male. Photo 

© Bruce Grimes.

Other meadowhawks, unidentified to species, all individuals with bright red thoraxes, have also been found at Rocky Knob on a few occasions. None recently, but our migration coverage has been scant the past two years.

Carolina Saddlebags(Tramea carolina). A small number are seen each migration season at the pasture. This species has been observed in significant numbers on the Atlantic coast, but is a quite uncommon migrant at Rocky Knob. Large numbers though have been seen at ponds in Franklin and Patrick Counties in lower elevation sites.

We have observed several dragonflies that were not likely any of these species, but they all have that category of "unidentified species".

The Xerces Society has begun an effort to monitor dragonfly migration on a national basis. Here is the webpage about the migration of dragonflies, protocols for monitoring, and more:

http://www.xerces.org/dragonfly-migration/

We plan to submit our Rocky Knob data on dragonflies to this site, and starting in July or August will begin the season anew, with reports sent to the Xerxes project. It's hard to believe that the next migration season is just a little more than a month away.

You are most welcome to join us at Rocky Knob. The more observers the better is my view. We tally many species of birds, the migrant hawks, the warblers, thrushes, finches, hummingbirds and much more. We tally the migratory butterflies, and that's another story in itself. And of course we keep records of the migratory dragonflies.

We often see good migratory flights of raptors, particularly kestrels, when we see good numbers of dragonflies on the move to the south. Our only sighting of Swallow-tailed Kite occurred on a day when we had a fine flight of Black Saddlebags. The kite likely fed on several dragonflies that day.

I encourage you to try watching for migratory dragonflies, and sharing what you find. You can post a note in reply to this blog posting, or submit your data online to the Xerces site, or both.

Happy migration watching to you.

Blue Grosbeak

On May 11 a blue grosbeak showed up at the house in Woodlawn. Because they aren't common here on the plateau, my wife and I enjoyed seeing it. They were plentiful during summers in Fayetteville, NC, where we lived for 30+ years. Seeing one here and adding it to our yard list was a treat.

Copperhead

Northern Copperhead

Agkistrodon contortrix mokasen

We went swimming

this weekend at Sugar Hollow in western Albemarle County, Va. The wildlife around and in the swimming hole was incredibly dense and diverse. The copperhead in the image above was one of the critters we got to observe. You can see the vertical pupil in its eye and the heat sensing pit behind the nostrils...both of which distinguish this poisonous snake from the many non-poisonous look-alikes (for some great comparisons of copperheads and other snakes, check out this link:

http://www.virginiaherpetologicalsociety.com/venomous-look-a-likes/copperhead-look-a-likes/copperhead.asp

) At the swimming hole, this snake stole the show. The more than 20 people that were there were buzzing with excitement over this snake. If you go to sugar hollow, keep your eyes peeled as you navigate the boulders along the creek. You just might get to see a copperhead...and you don't want to step on one.

Not too far away was a northern water snake hunting along the stream's edge. Not too far from that were puddling butterflies; spicebush swallowtails, red spotted purples, and eastern tiger swallowtails. Brightly colored sleepy orange butterflies, eastern commas, eastern tailed blues, and silver spotted skippers were abundant as well. 

My girls spent a good amount of time catching fish and butterflies. Norah captured dozens of at least two different species of fish and enjoyed observing them in a holding tank. Eva showed off her net-free technique of catching butterflies. She's been practicing a very patient and skilled approach for about 2 years now...and she's got it down. She even picked up an eastern comma butterfly...notoriously skittish. 

It was an awesome day.

Is it a yellow jacket wasp or not?

Whenever an insect lands on you, it is time to pay attention and figure out if there is going to be a problem! Is there going to be a bite or sting or just a tickle with no further consequences?

I recently noticed a scary-looking small bug on my leg while biking and decided to check this out since it strongly resembled one of our most feared wasps, the yellow jacket. Now yellow jackets are not to be trifled with as I have learned several times when I have had to deal with their formidable nests. They are fierce and have a strong sting and an attitude to boot. On closer inspection I realized that although this bug (see photo of syrphid fly) is a close mimic of the yellow jacket wasp, it is in fact a fly. How did I figure that out? I look at the wings and can see that there is only one pair of wings (wasps have two which fold back). The eyes in flies are larger and placed differently and the antennae are shorter. If you can see the mouth, flies have sucking or piercing mouth-parts whereas wasps have chewing mouth-parts. Flies also behave somewhat differently - for example this bug was drinking sweat from my leg- in an apparent attempt to pick up some salt/sodium which is lacking in their mostly herbivorous diet. With some practice you will be able to make this distinction too, so do not just dismiss the swarm of bugs flying around you in Summer-time, have a look at them carefully and pick out the pretenders from the real bad dudes.

Now just when you have the flies separated from the wasps, along comes another yellow and black critter (see photo of locust beetle) which is not uncommon in our yard since we have a lot of black locust trees. This is an entirely different type of insect (a beetle instead of a fly or wasp), yet it is colored rather similarly and seems to be also mimicking a yellow jacket to obtain protection from predators. Birds likely recognize and avoid yellow jackets and their mimics which fosters the evolution of such convergence in color and pattern. This does not work on mammals such as skunks which make a good living by digging out and eating the young found in the nests of yellow jackets. Indeed skunks, which themselves are well protected by scent and advertised by a striking color, are highly thought of in our neighborhood by farmers who value them for their ability to destroy yellow jacket nests which can cause a lot of pain during haying time.

So learning the basics of insect identification can pay dividends not only in terms of protecting your own hide, but will add to your understanding and enjoyment of the natural world.

Bill Dunson

Galax, VA & Englewood, FL

Beware the red eft

While on one of my daily nature walks I looked down and spotted one of the true beauties of the woods, a red eft (see photo). They wander around, especially after rains and are very slow-moving and unafraid. Of course there is a reason for this- they are protected by a very potent poison, tetrodotoxin. You cannot be poisoned by handling the young newt, but if you eat it your nerve cells will have some severe problems. The bright orange/red coloration of red efts, which are juvenile stages of the red-spotted newt, clearly warns potential predators to leave them alone. As the red efts mature into adults, they become more greenish-yellow (see second photo). The adults return to the water where the gilled larvae started life and spend the rest of their lives there. This "reverse" life history (embryos, gilled larvae and adults are aquatic, but juveniles are terrestrial) is in contrast to typical amphibians, where only the embryos and larvae are aquatic. While there is much about this process that is unclear, it does seem likely that such an alternation of generations between habitats is probably a means of minimizing competition for limited food resources. One strange thing is that not all populations of newts have an eft stage, perhaps due to unsuitability of land habitats or less competition for food in the water. A similar phenomenon may cause retention of gills in some populations of tiger salamanders (leading to presence of aquatic, reproductively adult axolotls that resemble gilled larvae).

Another really interesting feature of red efts is that they are probably mimicked by other amphibians such as the red salamander (see photo). This latter creature is apparently tasty but may be protected by its resemblance to the very toxic red eft. Isn't it intriguing how the color red has come to be used as both a warning and an attractant, for example as the prime color for flowers used for nectar by hummingbirds, and as the color of ripe fruits? Remember also that the recognition of the color red requires that an animal has color vision, which many mammals do not. So the target predators for this red-hued message by the efts is likely to be birds.

Here we have another example of the complex interactions that govern the lives and appearance of critters- just amazing!

-Bill Dunson

Galax, VA & Englewood, FL

The mysterious blue-tailed skink

One aspect of natural history that fascinates me is the hidden lives that many species of animals lead right under our noses. For example out in your yard there are literally dozens of sizable critters that you do not pay any attention to since they are hidden from your view by their nocturnal or cryptic habits. For example you would be surprised at the number of things that lurk under the leaves/compost/mulch in your flower beds or behind the shed. Probably you would be happier not to know about them! In Florida we are blessed/cursed by some remarkably huge and somewhat scary insects such as the "palmetto bugs" aka roaches, earwigs, and most impressive of all the giant whip scorpions or

vinegaroons

. But also living in this community of creatures of the leaf litter layer are some interesting reptiles such as geckos, scarlet king snakes and scarlet snakes, ring-necked snakes, and the lizards called

skinks

.

To observe this hidden life of the leaves and soil I put out pieces of plywood on the ground and occasionally pick them up and see what is underneath. In addition I bury a bucket in the ground up to the edge and put a piece of plywood over the top. This pitfall trap collects things such as lizards which are otherwise hard to catch. Look at the photo of one such bucket trap and you will see 3

skinks

that were caught. These are probably all different sexes and ages of the southeastern five-lined

skink

. Juveniles have bright blue tails and adult males can have blue tails that are not so bright (see photo).

Most of you have likely seen these

skinks

when they are active foraging on the surface or even in trees. If you or a predator grabs them by the tail it breaks off and continues to wriggle, attracting the attention of the attacker while the lizard escapes. The tail will re-grow but it is not the same structure. Now the adult males of some species of

skinks

have long been considered venomous by rural folk who called them scorpions. This has been considered a foolish country legend until recently when it has been shown that these

skinks

, while not venomous, are indeed toxic if eaten by a predator. Cats in particular have been reported to be affected by a toxin if they eat these lizards. It is interesting that the blue tail color seems to serve two functions, to divert the attack of a predator to the tail instead of the head, and likely to warn predators that the lizard is toxic. The use of blue coloration for this purpose is interesting since it less commonly used to warn predators than red or orange.

Another interesting habit of these lizards is that you will occasionally find females that are "incubating" eggs by curling around them. This is not a true incubation since no heat is released by the female. But the presence of the female likely greatly enhances the survival of the eggs to hatching. Such maternal care is indeed known in some amphibians and other reptiles such as alligators and pythons and illustrates how primitive vertebrates can engage in what we might consider higher levels of behavior.

So go ahead and clutter up your yard and put out some small sheets of plywood (tell your neighbors they are "cover boards" you are using to census your leaf litter

faunal

communities!). You will be amazed by what you find but remember that these critters need moisture and natural compost to thrive; try not to spray any pesticides or herbicides. The resulting assemblage of critters will not only provide some exciting exploring with the kids but will produce a dividend by allowing for biological control of some pest insects by your home-grown predators.

Bill

Dunson

Englewood

, FL &

Galax

, VA

The Amazing Bald-faced Hornet

I came across a bald-faced hornet nest (actually a type of yellowjacket) in a tree while I was cutting brush. After most of the hornets had died from cold weather, I cut the nest open to examine the contents, and was amazed by its complex structure. There are several outer shells of paper (made from scrapings of wood), an entry hole at the bottom, and a series of shelves of combs (see my photo with a hornet sitting on the comb which is made up of hexagonal cells). There are hundreds of infertile female workers and a fertilized queen in the hive, and they defend the nest very vigorously! They are mainly predatory and feed primarily on insects.

This represents a typical Hymenopteran caste system made up mostly of infertile female workers, where the males appear only at the end of the seasonal cycle to mate with new queens which then over-winter to restart the entire life cycle the next season. So this life cycle relegates the males to the most basic aspect of pure reproduction- a bag of sperm !

The alternation of extreme activity during the Summer, with the eventual death every year of the entire hive, except for the newly fertilized recently hatched queens is incredible. The lives of these tiny automatons seems so strange to us, yet they are quite successful. The hexagonal geometry of the comb is interesting in its simplicity and efficiency. How remarkable are the lives of these highly social, but behaviorally rigid insects !

Bill Dunson

Galax, VA & Englewood, FL