New Photos, 9/3/10

The photos I've added to my gallery this week are from a trip to visit family in upstate New York. My parents get a lot of bees and butterflies in their yard, so it's usually a good opportunity to get something interesting while I'm there.


Swarms of bumblebees were crawling into these flowers before they opened each morning. The rustling sound and weird mouth-like movement of the bud was very much like something out of Little Shop of Horrors.


I always see these brassy sweat bees when I'm there.


This fritillary was a nice surprise. Very bold, really didn't mind having its picture taken.

New Photos

Sorry for the lack of posts lately -- been a hectic couple of weeks. Lots of work, lots of back and forth, and very little time to sit down to get through photos. But here's a few that I added to my gallery this week.

Long-horned bee

A male long-horned bee, possibly in the genus Melissodes, drinks nectar from a sunflower. The long-horned bees, or Eucerini, are a large tribe of solitary bees that dig nests; like most solitary bees the actual nesting habits varies from species to species, but none of them build the huge nests we associate with honey bees. And none of them have the same complex social structure with queens, workers, and drones. The Eucerini get their name from the extremely long antennae of the males: the word itself means "true horn".

I see large crowds of these bees on sunflowers near me, especially in mid to late summer. The males hang out and drink nectar, and wait for a chance to mate with females who stop by for a break in their constant pollen-gathering. They start early and work at it all day: I walked past some at about 8:30am this morning and there were several females with heavily-loaded pollen baskets. A few miner bees and tiny sweat bees as well.

I took this shot yesterday afternoon. It's at a 1:1 magnification ratio, so just the macro lens without any tubes. The flash, a Canon 430EX II, is mounted on a bracket I put together, and shot through a diffuser made out of an old yogurt cup and Rosco diffusion paper. Unfortunately, right after I finished with these bees and started walking to the next place I hoped to find bees, the off-camera cord I had the flash mounted on literally ripped off of its threaded mounting post, and bungeed down onto the street. No damage, I think, since the coil-cord slowed its fall, but it's making me seriously rethink the value of using the cord's hotshoe as a mount: obviously there's too much flex and stress with the flash's center of gravity so much higher than where it's secured.

The identification of this bee proves difficult. I got several clear shots of the wing venation, an important characteristic to select between the hundreds of species of bees in New England, and one or two showing the color and texture of the thorax very nicely. With this, I used the bee genera guide at discoverlife.org to narrow it down to a few species in several genera that don't really look like perfect fits -- different proportions and eye color, for example -- or one eleven species in the genus Melissodes, which I think this probably is. The guides at discoverlife.org are highly detailed keys that need more knowledge than I actually have, not to mentioned a mounted specimen and a microscope, to take full advantage of, but it's still extremely useful in drilling down with the right shots. Once I repair my rig, I plan to go back to these flowers at night to shoot them sleeping -- the males really don't seem to leave -- and hopefully get a few other details that will help confirm the ID.

Lucanus capreolus

Reddish-brown stag beetle
Lucanus capreolus

Here's a big little beast. This reddish-brown stag beetle is about an inch long, with a thick, deep red body and huge mandibles. They look like an over-grown, over-armored army ant, but in fact the jaws are not terribly powerful. (From what I hear -- I haven't been pinched by one personally.) The beetle doesn't need them to be: the adults feed on tree sap, and the females have little nubbins instead. Well, really the females have normally-proportioned mandibles for a beetle of their quite large size, but in comparison to the males', they look a bit dwarfish.

Given that these oversized mandibles are useless for foraging and impractical for defense, and that it's the males who lug them around, you can immediately guess what they're for: wrestling. They fight over breeding territory, and the biggest mandibles gets the ladies. After mating, the female lays her eggs in rotten wood, which feeds the larvae as they grow over the next few years.

I found this particular guy upside-down on the sidewalk, fairly early in the morning. They're crepuscular animals, meaning they come out at dawn and dusk, so he was probably wrapping up his morning activity. No idea how he got flipped over, but they're not very graceful fliers, and he may have just tired himself out. They seem to play dead when on their back, like many insects, but I wonder if that's a defensive response or if they just take a moment to gather their strength. At any rate, I brought him home and stuck him in a clean plastic cup, with some paper towels for cover, and gave him a few drops of sugar water later on.

To shoot him, I turned a small cardboard shipping box into a lightbox, by cutting away a few extra sides and flaps, taping white printer paper along the inside, and covering the top with Rosco 1/4 Tough diffusion paper. I put the 430EX II on a light stand directly overhead, and used the WhiBal to nail the color temperature down and get the exposure in the right ballpark. I took a few shots at 1:1 with the 100mm Macro, and made a series of four verticals to merge into a hi-res horizontal, but he moved around a bit as I was shooting and they don't have a consistent focal point. This is one of them.

Identification was simple. Any huge beetle with huge mandibles is probably one of the stag beetles (Lucanidae), and we only have a few in New England. Lucanus capreolus is dark red, with a lighter yellow thigh. I was pretty confidant after flipping through Marshall's guide, and then checked the key on bugguide.net to confirm it. There's another species, L. elaphus, with even larger mandibles, but the ones on this guy are only about as long as the pronotum (the head). It's not visible in this image, but he has fan-shaped clubs at the end of the antennae, the eyes are slightly divided by a little protrusion called a canthus, and the surface of the pronotum and the elytra (the wing covers) are pretty smooth. All these things say Lucanus, and rule out other related stag beetles.

Photos from this week

Some new photos from this week:

Scytodes thoracica

Spitting Spider
Scytodes thoracica

This handsome little spider is, literally, a spitting spider. Their silk glands are located next to the venom glands in their head (well, the cephalothorax), instead of the abdomen, like many more common spiders. They don't spin webs at all, preferring to stalk their prey at night. Once they've gotten close enough, about a centimeter or so, they spray a line of venomous liquid silk from their fangs, snaring the prey. And then they eat it.

This is the first spitting spider I've ever seen. I pulled out a bowl for some cereal, and lo and behold, there was a spider with these really neat markings in it. Nature is everywhere, even the cupboard. It's a very small spider: this photo was taken at 2:1. I used the Canon EF 100mm f/2.8 Macro USM lens on extension tubes, lit with a 430EX II. The flash was shot through a 43" umbrella mounted on a lightstand; ordinarily I would say that's an impractical setup for macro, but the spider wasn't going anywhere and I had the whole thing set up in the living room already, except for the lens. Post-shoot wrap-up consisted of tossing the spider outside and getting a new bowl for the cereal.

It was a pretty straightforward animal to ID. The distinctive markings would have made it easy if I had known about this species, but I didn't and so purposefully ignored them: the spider was small enough to be a juvenile of one of the more common kinds I see around the house, and color patterns are really variable in many spiders. Judging by the large cephalothorax (the front section, with the legs), I didn't expect it to be a weaver. The eyes jumped out at me though, definitely not a jumping spider. There are six: a pair of median eyes in the center, and a pair of lateral eyes high on each side of the median eyes, partially hidden in the dark bands. So I turned to BugGuide's guide to spider eye arrangements, got momentarily concerned because of the resemblance to the recluse spiders, and then found the species immediately when I checked the Scytodidae. There's only one genus and a few species, and as it turns out, the markings for S. thoracica actually do look pretty useful for identification.

The Albany Pine Bush

I was in upstate New York for the weekend, and took a trip to one of my favorite nature spots, the Pine Bush. It's a pine barrens, which means an ecosystem on dry, acidic soil -- usually sand -- dominated by short shrubs and grasses, and a modest growth of trees. Pine barrens would, in time, naturally be converted to more traditional forests, but the dry soil and abundance of low vegetation lead to frequent fires that clear out new trees that would, in other circumstances, out-compete the pitch pine, heaths, and scrub oaks that thrive there. New Jersey's coastal pine barrens are famous, but the Pine Bush is considered to be one of the best example of an inland pine barrens in the world.

The Pine Bush is home to a number of rare or unique plants and animals, and there is considerable pressure on it from developers, particularly Crossgates Mall and the Albany City Landfill, both right next door. It's terrible farmland, and one of my field guides quotes a 19th century author as calling it "as forlorn, miserable and unsatisfactory a combination of sand, swamp, and aridity, as the Union can produce", and "a mistake in nature". Now, of course, we appreciate such areas for qualities besides their agricultural potential, but for a long time they were something that needed fixing, and two-thirds of the pine barrens in the northeast were either destroyed for their sand and pitch, built over, or taken over by other ecosystems due to systematic fire prevention. I blame, in part, Smokey the Bear.

I visited the Karner Barrens section of the Pine Bush, and photographed some of the pitch pine/scrub oak community there. I was really hoping to see the endangered Karner blue butterfly, but was disappointed, not surprisingly. There was, however, a a controlled burn performed recently along the trail I walked -- the Albany Pine Bush Preserve Commission is responsible for fire management, and regularly burns small sections of the Preserve to maintain a healthy pine barrens ecology, and to avoid the build-up of fuel that would enable a larger, uncontrollable fire in the future.

My full gallery of photos from the day can be seen here.

House spider cannibalism

These two house spiders (Parasteatoda tepidariorum) either just mated, or were about to, as far as the male, in the lower left was concerned. Unfortunately for him, sexual cannibalism is common in spiders, meaning a female will often eat the male who just fertilized her. Praying mantises are infamous for this, but it's really the arachnids who make a habit of it. Males of different species have different strategies to avoid this, whether by bringing a large piece of food, waiting until the female has recently molted, or just by being quick and sneaky. Some scorpion males will even sting the female to subdue her until he's safely away. But other arachnid males will let themselves be captured by the female, or simply don't have good luck in escaping freely.

Interestingly, these two are pretty close in size. The likelihood of a male being eaten by the female is pretty much proportional to the size difference between the two, since females are usually much larger. So it seems quite possible that this is a species where the male lets the female eat him.

If you look carefully, the male has some webbing wrapped around him, and his legs are curled in the classic spider 'death pose'; I stuck around for a few minutes and she immediately started biting at a joint in one of the legs, but I had to leave before I could see if she was just subduing him with venom or was actually starting to eat. He's missing his front left leg, and on a 100% crop a drop of clear liquid is visible in it; I wonder if the digestive enzymes spiders inject into their prey have already taken effect, but I have no idea if it would be visible in a leg wound like that.

Carpenter ants at work

I just posted a gallery of black carpenter ants harvesting honeydew from a herd of aphids. A colony will tend a large number of aphids, protecting them from predators and culling the infectious sick, collecting the sugar-rich secretion the aphids produce in return.

Also some cool shots of two ants exchanging their stomach contents in a process called trophallaxis. The whole colony will have similar proportions of food in their stomachs because of this sharing of food. Gross, but very cool.

Lily Leaf Beetle

This handsome little beasty is a lily leaf beetle, an invasive insect from Europe that has chewed its way through the lilies of Montreal and New England. It's been called the 'scourge of Cambridge'. Apparently the University of Rhode Island has been experimenting with parasitoid controls -- i.e., another species that, in the beetle's natural range, uses (and kills) the beetle as part of its life cycle. Ichneumon wasps are a type of parasitoid, though they wouldn't touch these beetles.

I'm still very happy with the flash bracket I used to take this picture, except for two things: the weight at the front makes it difficult to stabilize, and I haven't found a good way to diffuse the light yet.

I'm considering picking up a 270EX or 430EX II to replace the Vivitar 285HV I'm using now. Both weight considerably less, and I expect E-TTL II would be helpful for macro work. The 270EX is tiny and cheap, but it's not terribly advanced. I'm also not sure if I would get the flash duration I want from a weak flash. When you lower the power on a flash, what you're really doing is lowering the amount of time the flash fires for, and faster flash pulses will freeze motion, like camera shake or wind, better than slow ones. So my thinking is that despite the extra weight of the 430EX II, it's a more powerful flash, and that might let me use a lower power setting than the 270EX or Vivitar 285HV. But naturally, both flashes cost money, which I don't have much of.

As for the diffusion problem, I'm still brainstorming. The problem is that I'm getting hot spots that lose all their detail -- look at the white glare on the lily leaf beetle's carapace. I'm also getting it on compound eyes and legs. I've got the flash in pretty close and firing it at 1/16th, so it's about as soft as it's going to get on its own. We'll see about this; I don't have a good idea for it yet.

Cellar spiders

I mentioned yesterday that harvestmen are one of a few unrelated animals to be known as 'daddy long legs'. Another is the cellar spider, Pholcus phalangioides. These are true spiders, unlike the harvestmen, and though they are very mildly venomous, it's unlikely to come across one with both the inclination and the ability to bite through human skin. This is another one of those species that people think, mistakenly, would be lethal if they had longer fangs.

These spiders spend most of their time hanging upside down in their webs, catching and eating smaller invertebrates. They're generally beneficial, since they eat pest species like mosquitos -- in fact they're useful for keeping down populations of certain dangerous spider species in Australia.

To photograph these spiders, I mostly used the DIY flash bracket I made. About halfway through I tried attaching a bounce card to the flash but found it kept hitting the webs and disturbing the animals. Eventually I realized that, as long as I was just in my basement photographing spiders sitting in webs, a tripod might be the better option. I do need to figure out some way to diffuse the flash a little better, especially for small reflective or translucent animals like these.

Another thing I realized in a discussion with another photographer on Flickr is that I keep all my photos in the same aspect ratio. The square crop you see above is a conscious effort to get out of that mental mold.

Harvestman

This morning was pretty chilly and not much was out in the way of tiny invertebrates. I was trying to get a better angle on a small spider who was hiding in a curled leaf, and as I stood up to move to the other side, I saw an absolutely gigantic opilionid, a harvestman, sunning itself on the leafy bush next to me. A much better opportunity. I ended up finding about a half dozen harvestmen in and around the bush, and a few one the surrounding trees as well.

They look like spiders -- they are fellow arachnids -- but there are a few important differences. For one, they don't spin webs (they lack the organs to) and have no venom at all. They mostly prey on soft-bodied animals like aphids, and actually have some value in agriculture as a species that contributes to keeping down pest levels. They'll also scavenge and cannibalize.

You can tell a opilionid from a spider quickly by two obvious clues. First, opilionids have two eyes mounted on a tubercule along the midline of the body, instead of the eight eyes spread along the front of a spider's body. Spiders and harvestmen both have a body composed of two main segments, a cephalothorax (the front head-torso region) and an abdomen, but while spiders have a narrow pinching waist that clearly marks where one ends and one begins. The two sections are much harder to determine in opilionids.

I'm pretty certain that the species I photographed is Phalangium opilio, and the bolder markings along the abdomen seem to imply that I found females. I am open to correction on both of these points.

Daring jumping spider

A daring jumping spider (Phidippus audax), in my bathroom. I saw it while getting ready for work, and ran to grab the camera -- didn't have time for a great shot of those green chelicerae but I was happy with this one.

Although they're large (this one was about a half-inch long I think), jumping spiders are harmless. Nothing to be afraid of from this animal. They're called 'daring' jumping spiders because they're quite aware of you when you're watching them, and they'll watch right back. Most spiders either have poor vision and won't see you, or have good vision and will run and hide. They're popular with arachnophiles because of this, and because of the metallic green chelicerae (think fangs) you can see in this image. They don't spin webs: you'll see them with silk tethers, but they only use them as safety lines while hunting or traveling.

Speaking of the macro bracket, I'll be posting an update on how it works with an off-camera flash cord later this week. My first impression is that the balance and weight are much better, and the flash is much more securely placed than it was with the Cactus V2s receiver. I do need to find some way of diffusing the light, though.