Category: arthropods

Readers’ wildlife photos

August 6, 2019 • 7:45 am

My photo tank is about half full, which means that I’ll importune you once again to send in your good wildlife photos.

Today’s contribution comes from Mark Sturtevant, crack arthropod photographer. His notes are indented:

The small moths in the first two pictures at first seemed too plain to bother with photographing, but they turned out rather interesting. The first is a tiger moth in the genus Virbia (I can’t get the species), followed by a Geometrid called Dyspteris abortivaria. I really like the delicate textures on the latter, since it looks like a piece of old parchment. Lepidopterists call it the ‘bad wing’ because it is difficult to spread its wings.

I was very happy to get the lovely moth shown in the third picture. This is the eight-spotted forester moth (Alypia octomaculata). They are usually challenging to approach, but this one was content to just sit with me while I took a large number of pictures. I shoot in full manual, and have never really picked up on metering with the camera. So getting the whites to not blow out while getting details in the back areas was tough!

The next picture is the caterpillar of the eight-spotted forester.

The little wolf spider shown in the next picture is a male in the genus Schizocosa. Note the fancy “leggings” on its front legs. This spider will likely use these in a display dance before a possibly cannibalistic female. I found a clip of such a dance here.

Next is a little but unidentified leafhopper nymph. This high-magnification picture was taken with a home made ‘super macro’ lens, consisting of a stock 50mm lens reverse mounted onto a helical extension tube.

I frequently see the very small but colorful wasp shown in the next picture. This is a cuckoo wasp, and they are parasitic on solitary bees and wasps. This one is possibly Chrysis angolensis. Cuckoo wasps are always hyperactive and very alert, but this one was content to just sit for pictures. The included link is to an article about the interesting biology of these little jewels.

One can count on finding large expanses of skunk cabbages in low-lying areas of forests. This is a favored hunting ground for our smaller species of bee-like robber fly shown in the last two pictures. I think these are in the Laphria sericea complex of species. Prowling around through the aptly named skunk cabbages is not entirely pleasant. Oy! The smell!

Readers’ wildlife photos

July 18, 2019 • 8:00 am

We have some photos and a story from reader Olen Rambow. His text is indented:

Attached are some wildlife photos taken in Shenandoah National Park in Virginia. I believe the butterfly is a female Eastern Tiger Swallowtail (Papilio glaucus), and the moth is a Royal Walnut Moth (Citheronia regalis). I was not able to identify the millipede. (I think it’s a millipede, rather than a centipede, as it appears to have about twice as many legs as body segments.)
I discovered that the millipedes above are not only aposematically colored, as they contain cyanide that makes then poisonous, but are also part of a Müllerian mimicry complex in which different species mimic each other’s color and pattern.
There’s a funny story behind the moth: We found it on our cabin doorstep in the morning and later saw that it was still there when we returned from a hike in the afternoon. I touched it with my finger, and it fell over onto its side, its legs twitching feebly. I assumed it was dying, and I took it inside, not wanting such a beautiful specimen to get stepped on or eaten by ants. My five-year-old son and I named it Charlie. For the rest of the day, Charlie lay on top of the chest of drawers, presumably dying in peace. Then at about 10 p.m., as we were drifting off to sleep, we heard a rather dramatic fluttering and thumping from Charlie’s side of the room. I turned on the light over the bed, and Charlie promptly flew straight into it, apparently in good health. My wife screamed, while my son jumped up and down yelling, “Charlie’s alive! Charlie’s alive!” I put him outside, and he flew off into the night. The next morning, he had returned to roost on our doorframe again. I guess the lesson I learned is that moths can sleep surprisingly soundly during the day.
I think the moth should have been named “Lazarus” rather than Charlie. Do you recognize the species? We saw this the other day:

You have mites on your face

May 22, 2019 • 11:30 am

As you sit there reading this, thousands of mites are living on your face, burrowed into the follicles of your facial hair and the pores around your eyes, nose, and mouth. As the NPR article below shows (click on second screenshot), every human is colonized by “eyelash mites”, members of the subphylum Chelicerata—yes, relatives of spiders and scorpions—in the species Demodex folliculorum. Here’s what they look like:

Source

Read more about them here, watch the video below, or do both (they give different information):

They pretty much rest head down within the pores from which hairs arise (several mites per pore), coming out at night to mate and eat the grease that your face exudes. Gross, eh?

But you don’t notice them, as they’re innocuous and rarely cause problems. Occasionally they will get out of control, usually when your immune system is suppressed for some reason. This causes a white sheen called “Demodex frost”, which looks like this (it’s a particularly bad case). But it can be treated.

Source

I find it interesting that this species, which is limited to Homo sapiens, is with us all of our lives, and does us no harm. I bet more than 95% of people don’t even know they have them. You’re not born with them; you acquire them from contact with others (most likely the mother) after you’ve exited the womb. And the good news is that they have no anus, so they don’t defecate on you. (They store their wastes for the duration of their short lives.)

Here’s a cool NPR video giving you more information about them. As expected, their low mobility means that they’ve become genetically differentiated among human populations, so you can tell where a mite came from by sequencing its DNA. It would be interesting to compare a phylogeny of human groups with that of their eyelash mites. If there is any “cross-group” movement, the phylogenies wouldn’t coincide.

Watch this, because these are on YOU!

Readers’ wildlife photos

May 22, 2019 • 8:45 am

While sitting at the airport, I just received a few animal photos from my old friend Peter, who once spent several years in Africa. It’s an unusual gathering of springtails in New England. Peter’s notes are indented:

This is a large group of Collembola crossing a dirt road in New Hampshire. I estimate the arc to be about ten or twelve feet long. However, in terms of the number of individuals on the move, this is like the sort thing one might see on the plains of Africa, only with wildebeest. It will probably take a couple of hours for them to cross the road.

The phylogenetic position of springtails seems to be somewhat controversial. They are arthropods (phylum Arthropoda), but it’s not universally agreed that they’re in the subphylum Hexapoda along with other insects. They could be a sister group of Hexapods but not nested within the Hexapoda. At any rate, here’s what a springtail looks like close up (photo from Wikipedia). And as you can see from the photo above, they’re small—at most a few mm long.

 

Your question: Why did the springtails cross the road?

 

Readers’ wildlife photos

May 9, 2019 • 7:45 am

Today’s contribution is from Mark Sturtevant, whose notes are indented:

Here are pictures that were mostly taken from various local parks in the late spring / early summer of last year. In what I call the Magic Field, the early season ground cover is teeming with various species of baby grasshoppers. I really like these little ‘hoppers since they are cute, but I do need to use a trick to increase magnification to photograph them since they are otherwise much too small for my macro lens. The one shown in the first picture is likely a very young red-legged grasshopper, Melanoplus femurrubrum, and it was taken by mounting the macro lens on a full set of extension tubes.

Although one might expect all the grasshoppers to be immature so early in the season, a notable exception is my favorite grasshopper that I see only in the Magic Field. The next two pictures show a young adult coral-winged grasshopper, so-named because of the colorful hind wings as shown in the linked picture.  This robust grasshopper overwinters as mature nymphs, so in the spring there are many adults flying around while all other grasshoppers are only recently hatched. One can see how well they are well camouflaged against the lichens and mosses that cover much of the ground in the Magic field. This large female was also very cooperative. What a beauty!

Next up are some damselflies. There are so many species of these around that it will be some time before I photograph most of them in my area. Adding to this challenge are the many species of ‘bluet’ damselflies,  distinguished in the field by the smallest differences in their markings so that I have no idea whether I am photographing a new species or one that I have taken many times before. The first one is likely to be the Hagen’s bluet (Enallagma hageni), and this was later discovered to be a new species for me.

The second one was definitely something new. This is the lovely sedge sprite damselfly, Nehalennia irene.

The boldly marked caterpillar shown in the next picture was a mystery at first, but from the pictures I determined that this was the larva of the Baltimore checkerspot butterfly (Euphydryas phaeton). That was pretty exciting since this is a butterfly that I had never seen before. So I returned the next day to the same spot, but the caterpillar was missing. A careful search of the area revealed it several feet away, lying motionless and limp on the ground. What happened? A possibility is that a hunting wasp that supplies its larvae with paralyzed caterpillars had found it. On occasion a wasp can drop their prey during transport and not find it again.

The story does cheer up a bit since some weeks later I came across an adult Baltimore checkerspot butterfly at a different park. This little beauty was well concealed in tall grass, but I was able to get this picture after trimming back the grass with scissors. Scissors are often very handy for this hobby.

Next are pictures that show more of the hardships of insect life. First is a caterpillar with cocoons of the wasps that had parasitized it. The wasps were likely Braconids, but I don’t know their species or the species of their caterpillar host. The doomed caterpillar was still alive when I found it, but quite unable to crawl away because it had been firmly fastened down with the silk from the cocoons.

I am lucky to have house centipedes (Scutigera coleoptrata) in my area. Besides running up and down the walls in our house, they can also be generally found sitting on the outside of the house during warmer weather. So we are pretty much surrounded. The last pictures show a large one that had captured a Noctuid moth drawn in by our porch light. Perhaps readers would enjoy watching this short documentary to learn more about house centipedes. For any person who is perhaps creeped out about these multi-legged beasties, this beautifully filmed but also humorous video will not make you feel any better about them 😉

Readers’ wildlife photos

April 24, 2019 • 7:30 am

Reader Mark Sturtevant has another great batch of arthropod photos. I’ve indented his notes.  Be sure to see the vestigial legs of the butterfly in the last two photos. I had no idea that some species had vestigial legs!

Here are pictures of arthropods taken during the winter and early spring of last year. A snowy winter day might not be considered a time for arthropods to become active outdoors, but various species are out and about even when there is snow.

One well known example are the tiny (tiny!!) black springtails that gather around tree trunks and exposed rocks during the latter half of winter. Springtails are a group of small arthropods that are not considered true insects even though they have six legs and antennae. They can jump with a muscular extension from near the rear of their abdomen. I presume the species that is shown is Hypogastrura harveyi. These can gather in the high thousands, peppering the snow in their numbers as can be seen in the associated link. My highest power lens was pushed toward its limit to take these pictures since these little critters are less than a millimeter long. Hard to find in the viewfinder too!

The next two pictures represent some of the insects that can also be seen during the winter or early spring. First is a sawfly (which is a kind of wasp) Dolerus unicolor, and next is a caddisfly. I have no idea of the species, but caddisflies are in the order Trichoptera (meaning “hairy wing”), and they are a sister group to the “scaly wing” Lepidoptera (the butterflies and moths). Their similarity to moths is pretty clear. Caddisfly larvae are also pretty similar to caterpillars, but they are usually aquatic. Most larvae in this order build a shelter out of twigs or sand grains, and they crawl around carrying this shelter with them. Some examples are here.

Anyway, different species emerge as adults at different times of the year, and they often swarm near water. Well before leaves were really coming out last spring, a local river had many hundreds, perhaps thousands of these insects fitting about on the branches of trees that overhung the river. Every twig was festooned with them. I was not completely happy with the pictures, so I came back within the week for another attempt. But because these insects are notoriously short-lived as adults, by then they had all vanished.

Before the main photography season begins in earnest I like to practice by visiting a local butterfly house. The final pictures were from one of these visits. The first is of a blue morpho (Morpho peleides), which is generally regarded as the star of most butterfly houses. They attract a lot of attention since they are among the largest butterflies in the world and they flash iridescent blue wings when in flight. They are good at disappearing when at rest since then they usually hold their wings tightly closed. This one was feeding from a rotten banana that was set out for the butterflies.

The next picture is the aptly named malachite butterfly (Siproeta stelenes), a species that ranges into the southern US.

Butterfly houses commonly stock several species of ‘long wing’ butterflies. These small butterflies come in a bewildering array of species, and many of them have different colors in different parts of their range as they have evolved to resemble another species of butterfly in complex systems of Batesian and Müllerian mimicry. The last pictures are of the tiger longwing (Heliconius hecale). Note in the first picture that this butterfly has a vestigial pair of front legs that are immobile and pinned to the thorax. This is actually very common among butterfly species. I suspect the reason for this is that since butterflies really only use their legs for perching and not for walking, it makes sense to vestigialize a pair of legs to reduce weight. Perhaps “vestigialize” is not a real word, but it does make sense.

Readers’ wildlife photos (and a video)

April 9, 2019 • 7:30 am

Please send in your good wildlife photos if you have some.

Reader Tony Eales from Australia continues his series of arthropods from his trip to Borneo. His notes are indented.

There aren’t too many insect orders left from my Borneo trip. Here we have Blattodea, Diptera and Hemiptera.

A lot of people think termites are ants, and a lot of stuff on the web still puts termites in their own order of Isoptera; but phylogenetic analysis shows them to be deeply nested within the Cockroach order Blattodea. They’re basically eusocial cockroaches. In Australia I am used to seeing them only if I lift a log or peel back some dead bark, but in the rainforest of Brunei they were out marching along a balcony rail like ants.

We saw more traditional cockroaches as well. A very large nymph or wingless female roach out on a ginger leaf on a night walk.

A medium sized roach with love hearts on its prothorax. Ignoring completely taxonomic accuracy, I’ve dubbed it the Love Bug.

And the smallest winged adult roach I’ve ever seen at about 3-4mm.

With my camera woes, flighty insects like flies were difficult to photograph and I missed, what may be, my only opportunity to photograph a stalk-eyed fly but I did get some other interesting dipterans. The first I have no idea of the family but the other two I am certain where Rhiniid Flies as we have similar species in Australia.

Rhiniids:

We also had many Hemipterans. The Flatid planthopper was almost identical to others I’ve seen in Australia. As was the Rice Bug Leptocorisa sp. (second photo). But both seemed like their colour was more “saturated” than the ones at home.

I also found an unidentified tiny nymph in a lovely shade of pink.

I also recorded the sounds of Cicadas calling at dusk. It’s an extraordinary call that sounds like a trumpet. They would call at the same time every day for about 15mins. Every time I listen it takes me back to the rainforest. The video is all hazy because my phone was in a ziplock bag to protect it from rain and humidity: