Category: insects and other arthropods

Readers’ wildlife photos

October 5, 2023 • 9:00 am

Mark Sturtevant, perhaps our most regular regular, gives us a lovely batch of arthropod photos. Mark’s text is indented, and you can enlarge his photos by clicking on them.

During the previous summer I sought new insect hunting grounds by spending a few days in Ohio. This is the first installment of my pictures from this trip. They include a mixture of species I’ve seen before, plus some that are new to me.

First up are a mating pair of Robber Flies. I don’t know the ID since there are so many species that look like this:

I am always happy to find a Mantidfly, since they are rather strange on a variety of levels. This one is Climaciella brunnea. I have shown them here several times, but remind you that Mantidflies are in the same order as more familiar insects like lacewings and antlions. They resemble praying mantids, and are thus a case of convergent evolution although they are not at all closely related.

Mantidfly larvae grow by invading a spider egg sac and feeding on the eggs while the mamma spider stands guard over her brood and is none the wiser. And finally, this species is a very exacting mimic of native paper wasps in the genus Polistes, although they of course mantidflies have no stinger. The link above is to a video of the same species, although its colors seem different.

The paper wasps they mimic come in a range of colors that range from mostly yellow to nearly black, and based on pictures I’ve seen, the Mantidfly does a pretty good job matching the different wasps. A few manually stacked pictures were taken of this one, and then it flew away:

Next up is one of the large Flat-backed Millipedes, probably Euryurus leachii. They were abundant under rotten logs in Ohio, and were new to me. Many species of millipedes from this group produce a hydrogen cyanide chemical defense, and that probably explains the bright warning colors:

Here is Walking Stick nymph, probably a young Diapheromera femorata. It was right next to a very cool spider that I will show next time:

Instead, here is Nursery Web Spider, Pisaurina mira, followed by a Triangle Orbweaver, Verrucosa arenata. The latter spider is new to me. Most of them are this color, although there is a variant that is bright yellow:

And finally for this installment, here are pictures of a beast that I had long wanted to see again since I first saw one as a kid. This is a Wheel Bug.  (Arilus cristatus), which is our largest assassin bug. At 33mm they are pretty impressive, and their bite is described as being rather painful (though some have disputed that, and I wonder who’d want to test it). I managed to find a couple nymphs (it being too early for adults), and brought one home for pictures. I kept it for a time, and it even made a meal of a caterpillar. After some weeks, it finally molted to the large adult seen in the final pictures. From the side you can see why they are called Wheel Bugs:

Readers’ wildlife photos

October 4, 2023 • 8:15 am

We have two sets of photos today from physicist and origami master Robert Lang. Robert’s notes are indented, and you can enlarge his photos by clicking on them. First, “bear camp,” and then two photos of scorpions.

Bear Camp

In August, we spent a few days at a camp in Chinitna Bay, part of Lake Clark National Park in southwest Alaska (across the Cook Inlet from Homer, Alaska). There we got to watch bears feeding on sedges along the river that runs into the bay, attempting to catch salmon when the river was shallow at low tide, and clamming on the mud flats in the Bay. Though it was perhaps not as spectacular as the bears that congregate at the famous Brooks River falls, we still saw plenty of bears, and the vast open spaces of Alaska made for a stunning background.

Bears weren’t the only wildlife we saw. On the way there, we saw this juvenile Bald Eagle (Haliaeetus leucocephalus) trying out his wings on a cell phone tower in the town of Homer (our jumping-off point for the final puddle-jumper flight to camp).

Once we got to Chinitna Bay, we regularly saw adults, though usually at a distance, and heard them more often than we saw them:

An amusing thing about bald eagle calls: in the movies, when they show bald eagles to establish “the wild outdoors” for a scene, they’ll often play the call of a red-tailed hawk, because an eagle’s actual call is a seagull-like chittering that seems incongruous with their majestic appearance.

During the trip, we also took a short boat ride on the bay that showed a few interesting waterfowl. First, a Black Oystercatcher (Haematopus bachmani):

This bird should be cancelled, of course.

And we saw a few Tufted Puffins (Fratercula cirrhata), including this greedy fellow:

What I wonder is, did it catch all five fish at once, or one at a time?

Another on-the-water sighting was a sea otter (Enhydra lutris). This one told us “I once caught a fish that was THIS BIG.”

The camp we stayed at was surrounded by an electrified fence, which sounds like a nice, secure barrier, but it was low enough that humans could easily step over it.( I suppose, though, that bears have a shorter inseam than humans.) It was no barrier at all for the resident family of red foxes (Vulpes vulpes), whose kits scampered all over the camp, wrestling each other and playing in the grass.

But enough with the small critters; let’s get to the main event. The Alaskan brown bears (Ursus arctos) were all over the place. We kept to a respectful distance, of course; they knew we were there, but in this area and season, food was plentiful, and they mostly ignored us in favor of sedges, clams, and salmon.

This time of year, the males had mostly headed to the high country, so most of the bears we saw were females, usually with cubs.

The cubs ran around and played and then periodically stopped to get drinks from Mom:

They mostly grazed in the sedge meadows to either side of the river, but at low tide would go into the river to hunt for salmon that were making their way upstream in the shallow water. The bears would stand up, looking for ripples in the surface:

And then when they saw something, make a mad dash for it:

Most attempts ended in failure, but occasionally, they got one. (Too far away to get a good photo, though.)

We sometimes got to a viewing site by driving along the beach. Our vehicle left tracks in the sand, but we weren’t the only ones doing so.

And lagniappe on scorpions:

 I know you sometimes show a batch of onesie-twosies in the Reader’s Wildlife Photos, so I’ll pass on two photos from a recent night hike on the trail behind my studio in Altadena. I took my UV flashlight to spot scorpions, which fluoresce green in UV light. So here’s one (unknown species, I would welcome expert ID). First photo is in UV, second photo is the same one with camera flash. For scale, it’s about 2” long.
There are some theories about why they glow (see, e.g., here). I can’t readily evaluate the strength of the argument, but it sure makes it easy to spot them!

Readers’ wildlife photos

August 7, 2023 • 8:15 am

Well, folks, this is the last substantive batch of photos I have in the tank. If you want more this week, you’ll have to provide them. These come from our most regular regular, Mark Sturtevant; his captions are indented and you can enlarge the photos by clicking on them.

This post has been on my mind for several years, beginning with an encounter that I had with a weird little fly on a bridge. Here is that fly (I think Pseudotephritina sp.), and I had probably shared it here once upon a time. It was marching up and down on the bridge rail while continually waving its wings. I did my best to photograph the little insect, which was no bigger than a fruit fly, with my little 50mm lens on extension tubes. But I wasn’t the only one interested in the fly. There was also a jumping spider, and it definitely was intent on having the fly for a meal! As the spider stalked closer, the fly would suddenly turn to it, waving its wings, and the spider would flee! This was repeated several times until the spider gave up. Did the stripes on the wings look like spider legs to the jumping spider? Jumping spiders do signal to each other by waving their legs. This is how they avoid conflict.

Now one must not make too much of this impression from a one-time encounter like that. But many flies in several different families have boldly patterned wings which they wave around. While this is known to act as intraspecific communication, it is thought that in at least some species flies also use this kind of display to scare off free-roaming spiders like keen-eyed jumping spiders. There is, for example, a classic paper concluding that another fly, Rhagoletis zephyria, would frequently display its patterned wings when stalked by jumping spiders, and spiders would tend to stop their approach in response. Here is a picture from that study, and one can definitely see that the fly does look like a jumping spider:

R. zephyria is part of a large species complex of flies that all strongly resemble each other. From the BugGuide web site, I count 18 species in North America. One of these is the apple maggot fly (R. pomonella), and I do have two apple trees and I see what I presume is that species of fly in the yard from time to time. It should be mentioned that the apple maggot fly is also a classic example of sympatric speciation, since the flies originally relied on hawthorn trees as their host. [JAC: the idea that the two host races of this fly formed sympatrically is probably not correct; see Coyne and Orr 2009). But with the introduction of apples into the country, some of them jumped to apple trees and there is now significant reproductive isolation between the two populations. Anyway, one of the flies appeared on my back porch last summer, and because I was able to catch it I could at last act on what has been on my mind for many years. Would this fly use its wings to deter a jumping spider? Mind you, this is a different species from the one described above, but … maybe? The following pictures record the results of this admittedly informal attempt to test that hypothesis.

Here is the fly, feeding on slices of sour green apples. It was quite content to just sit there and feed since I had starved it for a day.

Now when this fly turns away from the camera, one can certainly see that its wing markings are very much like spider legs. Both males and females display their wings when encountering one another, but what would happen if I introduced a jumping spider?

So out to a local field I went, and soon returned with a test subject—a handsome male Phidippus clarus [see citation below]. What would happen if the two met? Would the fly react to the spider? Would the spider react to the fly (other than making a meal of it)?

In my arena I had the fly, feeding away, and the spider was kept several inches away under a clear plastic cup. When the spider was facing the fly, I would then lift the cup and make ready with the camera. After about 10 tries (I should have counted, but I didn’t), I could definitely say: I am not sure! Most times the spider did look at the fly, and sometimes it paused to look at it, as it was doing here for some seconds. But then it would turn and walk away. At no time did it stalk the fly, nor did it hustle off like it was fleeing. So I can’t “read” what the spider saw of the fly other than that it wasn’t prey.

Meanwhile, the fly just kept feeding, and it did not seem to react to the spider at all. But on one occasion – just one! – the fly certainly did seem to react to the spider by suddenly spinning around (it was facing away before), and it held out its wings. Here is that moment, with the fly out of focus in the background.

And here is a second picture, now focused on the fly. That is not a relaxed posture. The spider for its part just paused briefly, and then moved away.

I don’t know what to say about this informal experiment, other than that the one response from the fly encourages me to try it again. I am currently keeping an eye out for more of the flies.

As a kind of postscript, there is this lovely paper which proposes that many species of insects from several different orders may be mimicking jumping spiders to ward off predation. There are lots of cool and enticing pictures, and the readers here will certainly enjoy having a look.

Thank you for looking!

Readers’ wildlife photos

August 5, 2023 • 8:15 am

We’re down to two or three sets of photos, so things are getting dire. If you have good wildlife photos, send them in now (but not between the 11th and 21st, when I’ll be gone). Thanks.

Today Tony Eales, back from his African safari, now sends us photos of African bugs. His captions are indented, and you can enlarge his photos by clicking on them.

As I said in an earlier post, there were not many bugs, June being well into winter in southern Africa. There were, however, still bugs and creepy crawlies of different kinds. Here are a few of them. Unfortunately I don’t really know much about most of these species but I’m reaching out to various places to learn more.

Found this cool grasshopper nymph in Moremi Game Reserve:  Abisares viridipennis:

At the same camp I found this lantern fly, probably Druentia sp.:

I found this strange bark mantis in Chobe. It barely has the classic raptorial forelegs that are usual for mantises. Amorphoscelis sp.:

At the same camp we found this elongated assassin bug, Rhaphidosoma sp.:

This mantis, while more classically armed, was very weirdly adorned to help it blend into the background. Sibylla pretiosa Cryptic Mantis:

We saw the evidence of a very unusual moth that could really only live in an area with thousands of grazing mammals like southern Africa. Ceratophaga vastella, the Horn Moth. Unlike the majority of moth larvae, these feed on mammal horns rather than plants. [JAC: the marks on the horns are caused by larvae; as Tony explained, “You can see the worm-like tunnels On the surface of the horn and empty pupal cases sticking out of the horn”]:

Here’s one of the major shapers of the landscape, Macrotermes sp. I don’t know if the species I photographed here are the same ones that are responsible for the large mounds that we observed, especially in the Okavango, but they are in the same genus. These termites are unusual in they are fungus farmers rather than eating the plant material directly:

Some of the more impressive insects I encountered were hymenopterans. Here is a Slender Tree Ant in the Tetraponera natalensis species complex:

Stingless bees Meliponula bocandei, much larger than the Australian and Southeast Asian species I’ve encountered:

Paltothyreus tarsatus, the large African Stink Ant:

A large velvet ant, Stenomutilla sp.:

And of course, I found a wide variety of my favourite group, arachnids. Including my very first member of the Solifuges, or Sun Spiders. Apparently this family (Solpuginae) of Sun Spiders is called Common Romans. I’m not sure what that is about.

I also found an Orange-lesser Thicktailed Scorpion (Uroplectes planimanus):

And these spiders were absolutely everywhere after dark. I was confused as by size and habit they seemed so much like the huntsmans (Sparassids) that I know from home, that I assumed that’s what they were. But in fact they were what are known as Flatties or Wall Crab Spiders (Selenopidae). I should have noticed the different eye arrangement. This one is probably Selenops sp.:

But my favourite spider was this impressive Wandering Spider (Ctenidae). As yet, I have no ideas about the genus but I’m asking a few knowledgeable folk about it:

Readers’ wildlife photos

July 18, 2023 • 8:15 am

Regular Mark Sturtevant is back with a batch of lovely arthropod photos. Mark’s captions are indented, and you can enlarge his pictures by clicking on them.

Here are more pictures of arthropods. Some are from area parks, and others are from my house here in Michigan.

First up is an Antlion larva, Brachynemurus abdominalis. One can find the conical pits that these little beasties make all over what I call the Magic Field. How they use their pit to ensnare passing insects is shown in this video.  Although they are easily extracted with a spoon to be taken home for pictures, actually getting pictures was not that easy since they generally want to scuttle backwards in an attempt to bury themselves. Right now, I am keeping a few larvae in cups of sand and feeding them ants (which is always entertaining), with the aim of later photographing the pupal stage. Antlion pupae are interesting in that they are still ill-tempered and they bite:

I came upon this wasp-mimicking beetle (Necydalis mellita) along a woodland trail. That it is indeed a beetle is proven by its elytra, even though they are very short. I’ve seen these before but could never get a picture because they are alert and flighty (wasp mimics tend to be wasp mimics all the way). But this one allowed a few pictures. It belongs in the longhorn beetle family:

Next up is a Big Sand Tiger Beetle (Cicindela formosa). These lovely but very alert beetles are common around here in sandy areas. Some days, nothing will get you a picture of one, but on this rather cool and overcast day the task was pretty trivial. Tiger beetles used to be in their own family, but now they have been absorbed into the ground beetle family:

Another challenging beetle is shown next. This is a tumbling flower beetle, Mordella marginata. Tumbling flower beetles belong to their own rather obscure family, and they are normally found on flowers where they eat pollen. There, the least disturbance will cause them to live up to their name as they curl up and fall to the ground:

Next are two grasshoppers because I really like grasshoppers. The first is a ‘hopper nymph of uncertain identity, but it most resembles the Two-striped Grasshopper, Melanoplus bivittatus.

Following that is the Northern Green-striped Grasshopper, Chortophaga viridifasciata:

Over the previous summer, I made it a regular habit to scour the front porch in the morning to look for insects that were drawn in overnight by our porch light. Among the more common squatters were these very small Mayflies which I believe to be Callibaetus ferrugineus. First are two females. The close-up picture is focus-stacked with my super macro lens, as are all of the remaining pictures here. She looks pretty strange, as all Mayflies do, but get a load of the male in the next picture.

Here is a male. I still remember my astonishment seeing the first of these! The upward turret-shaped portion of their compound eyes are thought to be used to watch for females:

This set finishes with a couple spiders. First up is a Slender Crab Spider, Tibellus sp. These are shaped to stretch out along grass blades:

And finally, here is a Ground Crab Spider, Xysticus sp. The super macro lens lets me peer into a new world, but I wasn’t expecting that face to look back from it!:

Readers’ wildlife photos

June 16, 2023 • 8:15 am

Mark Sturtevant is back with another batch of spider and arthropod photos (“harvestmen” aren’t spiders). His captions and IDs are indented, and  you can click on the photos to enlarge them. Our photo tank is nearly empty, by the way. Sunday may be our last day!

Last summer was a good one for getting some especially nice buggy pictures, although work and being dragged to vacation in urban areas did reduce the volume of pictures that I could gather. But I did my best. This set is all about some early-season spiders.

There was a big marbled orbweaver (Araneus marmoreus) in the garden late in the previous season (you saw pictures of her), and she left an egg sac. So early this summer my wife reported that they had hatched, and here are the bebbies. They would disperse when disturbed, but after a time they would gather together again into a tight little ball of tiny spiders. I love all those little baby bums! 

Here are some focus stacked pictures of jumping spiders, taken with the manual Venus/Laowa 2.5-5X wonder-lens. Jumping spiders are of course very active, so high dozens to over a hundred of pictures were needed to get successful but short stacks. It also helped to use psychology on the subjects, as explained below. 

The first one is a tiny ant-mimicking jumping spider, Myrmarachne formica. Readers may remember a male of this species that I had recently shown which had over-sized chelicerae. The one here is a female. To get her to stay in one area, she was marooned on a leaf that was pinned out in a cup of water. Since she was unwilling to cross the moat, I could zero in on her much more easily. No subjects were harmed in taking these pictures, btw. 

And here is our charismatic bold jumping spider (that is its common name), Phidippus audax. It is useful to think of jumping spiders as being like cats, so here I fashioned a tiny cup out of a leaf and let her explore it. Being cat-like, she had to sit inside the cup, and she even sat still for almost a minute which is an eternity for such spiders! 

Here she is again, but now she’s pausing atop a foam rubber stopper while sizing up the distance between her and the lens (she attempted the leap several times). You can see that one of the front legs had been regenerated. 

Here is a close crop of the previous picture, and this show-cases the incredible quality of this super macro lens. Y’all should click again to embiggen this one! Many hours were needed to clean up most of the artifacts from the focus stack and from the Topaz Sharpen AI program that I’ve also started to use, but the result is a contender for my favorite critter picture. The eye reflections are the diffusers that were used on the twin flash. Those diffusers are now being re-built, as is required since that is one thing that must be regularly fussed over in this hobby.

 

Next up is an unknown species of wolf spider carrying her egg sac. I did not know that adult wolf spiders could be this small. 

And finally, this is a focus stacked picture of a female harvestman (likely Phallangium opillio). OK, it’s not a true spider, but just look at that weird little face! Male faces are even stranger, but they are super restless. I will do my best to get the picture this summer. 

Readers’ wildlife photos

May 16, 2023 • 8:37 am

Today we have a batch of insect and arthropod photos from regular contributor Mark Sturtevant. Mark’s captions and narrative are indented, and you can click on the photos to enlarge them.

This set of pictures, taken a couple of summers ago, begins with rather ordinary examples of the arthropods from where I live (in Michigan). But to our mutual delight, the later pictures become rather weird.

First, here is a new species of meadow katydid that I had found near where I work. Normally, the small meadow katydids that abound in late summer fields are a short-winged species. But this one was clearly different. This is the slender meadow katydid, Conocephalis fasciatus It is a small but still satisfying thing to be able find a new katydid after so many years in the hobby.

Next is a weevil that I always call “that lumpy weevil”, because I’ve seen many of them in our yard but have never photographed because they were the size of a poppy seed. But now I have a super-macro lens (the manual Venus/Laowa 2.5-5x lens), and that can make short work of small things like this. So here is a manually focus-stacked picture of that lumpy weevil. Because of this picture I now know that they are really called the plumb curculio (Conotrachelus nenuphar), and that they are serious pests of fruit trees. We do have a couple of apple trees, and we have a neighbor who somehow manages to have a peach tree. So there’s little wonder that the plum curculio is common in our yard.

Fall comes quickly here, with cold mornings even while the insect season is still thriving. I had gone out one chilly morning to a nearby field (I think it was to find critters to feed to a praying mantis), but of course the camera tagged along in case. On this occasion, I came across a female green darner dragonfly (Anax junius) nestled deep in a tree. She was much too cold to fly, and so it could be moved to a perch for pictures. These are manually focus stacked images. Soon after, the sun had warmed her sufficiently and she was off in a flash.

The next two pictures are of spiders, and they both came to me via a close friend who lives down the road. After visiting down the road one evening, I came home late at night but then noticed there was a tiny spider dangling from the brim of my hat. It turned out to be one of those ant-mimicking jumping spiders, but this one was definitely a new species to me since it had ginormous chelicerae. This little oddity is Myrmarachne formicaria, photographed with that Venus/Laowa wonder-lens. The large chelicerae means that it is a male, but what they do with them I am not sure although no doubt it has something to do with mating. This species was recently introduced into the U.S., and it may be the first recorded citing of it in my state.

The second spider arrived when the same friend called me on the phone to tell me that a spider had ridden with him on his motorcycle to a store and back. Do I want it? Sure! So he pulls up on his ride and the spider turns out to be a flower crab spider (Misumenoides sp.). Nice, but not unusual. Here she is, a little gritty from the road. But things became weird while processing this picture. First, look at those two frontal eyes in the middle of her face. Do you see the expanded dark areas of color around them? Those are pigmented retina cells inside the head of the spider, and you can see them because the cuticle is translucent.

While assembling the focus stack for the above picture, I noticed that the dark retina cells were moving around in the head. You can see that with this two-frame gif animation made from pictures that focused on the eyes.

What is going on? It is well known that jumping spiders, which have very large frontal eyes, use little muscles in their head to move their retinas around to look out in different directions. You can see this clearly from this video. But this crab spider was evidently doing the same thing! After some research, it was learned that being able to move retinas around from behind the frontal eyes is a pretty widespread thing among spiders, so jumping spiders are not unique in this ability. These discoveries are one of the great joys of this hobby. After an entire life being absorbed by insects and spiders and such, and years spent photographing them, there are still new things to learn.