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Andrew Johnston

@andrewjohnston.bsky.social

Insect systematist fascinated by beetles. Assistant professor and Insect Diagnostician. Desert explorer.

35 Posts726 Follower156 Folgt
Andrew Johnston@andrewjohnston.bsky.social · 9mo ago

Thinking about buying a macro lens for insect photography? Along with @ageofarthropods.bsky.social we have been testing many options! Our results are summarized in 2 blog posts in the field www.insectid.org/post/macro-l... and in the lab www.insectid.org/post/lab-tes...

Macro Lens Comparison in the Field

As I continue to dive deeper into insect macrophotography, I have been exploring lens options and fallen down many YouTube rabbit holes and read probably hundreds of photography blogs and customer rev...

insectid.org

Andrew Johnston@andrewjohnston.bsky.social · last yr.

Two specimens of Megetra punctata from southeastern Arizona. Surprisingly the smaller one was a female and the larger a male - I think size is totally related to how much blustery ooze they have left in them and not correlated to gender. These things reflex bleed as soon as they are touched!

A large, seemingly inflated black beetle with orange red markings on it. The abdomen is blown up and it has tiny hardened front wings which don’t cover its body. A smaller individual of the same species which seems to have had the abdomen shrivel up some. The large individual curled into the fetal position with an orange glob of its toxic blood secreted around its head to avoid predation and hopefully deter entomologists. Unfortunately for him, I had forceps.
Andrew Johnston@andrewjohnston.bsky.social · last yr.

Want to set up your own photo-stacking imaging system for under $3000? This post which outlines all the off-the-shelf items I used this year along with some recommendations for how to use it. Planning to talk about this at @entcollnet.bsky.social this November, too! www.insectid.org/post/focus-s...

Focus-stacking photography: Building your own system

Ten years ago, Alex Wild published a guide on Scientific American on how to make your own focus-stacking system for under $6000. I can't seem to find that post any more, just some secondary posts with...

insectid.org

Andrew Johnston@andrewjohnston.bsky.social · last yr.

I hacked into a trunk of a Japanese Cherry tree sent for diagnosis of borer damage. These silly Camphor Shot Borers were inside (Cnestus mutilatus). They look like their backside was chopped off - but if you find them in their galleries you find out how effective they are at keeping them safe!

A reddish brown beetle hides in its circular gallery inside a tree branch cut in half. The beetle looks like it was sawn off along with the wood when it was split.A side view of the reddish brown beetle inside of its gallery. The gallery walls have some white ambrosia fungus growing inside which the beetles brought with them. The beetle fit snuggly in the gallery and could not be easily removed by another insect its size.The beetle is crawling out on the wood. The proportions are off for a normal beetle with the head and prothorax being about equal to the rest of the body.A more hardened individual with black cuticle walks along the split stick looking for a crevice to get into and hide from the camera lens.
Andrew Johnston@andrewjohnston.bsky.social · last yr.

I received a sample of Tuliptree yesterday with a concern for mealy bugs or aphids. What they had seen were these lady beetle larvae (Hyperaspis sp) which I always have to flip over to be sure about. They had been grazing on a massive scale infestation which had caused a thick sooty mold outbreak.

A white fluffy mass of wax that looks a bit like a colonial wig crawls along the underside of a green tuliptree leaf. Between the cottony wisps you can see hints of the pinkish red cuticle of this insect larva. The same larva is now crawling up the narrow leaf petiole. This picture shows its underside which is pinkish with dark legs. The insect is seen again on the leaf surface from the sideA pinkish almost alien looking insect host is shown under a microscope after being preserved in alcohol. Its head is visible here showing a black modeled shape with short antennae and mandibles.
Andrew Johnston@andrewjohnston.bsky.social · last yr.

I learned two new aphids this week, both from black/river birch. The streaked river birch aphid was quite handsome while the waxy Spiny Witchhazel Gall Aphid has a super cool biology with alternating hosts (witchhazel and birch) and makes those puckered creases in the leaves of birch

An adult streaked river birch aphid sits on the underside of a green leaf. The aphid is pale yellow-green with black stripes down its head and thorax and has skinny black legs and dark black wing veins on otherwise transparent wings. The underside of this wrinkled birch leaf has a crevice full of wax and flat oval insects. Most of them are reddish immature aphids which are joined by two darker colored adults, one with wings. They are covered with patches of white wax which they excrete for their own protection. A deformed and puckered leaf of a river birch shows signs of sooty mold and discoloration of dead leaf tissue. The gnarled ridges (pseudogalls) are formed by an aphid pest. The underside of the same birch leaf is shown where a few waxy aphids can barely be seen inside the folds caused by the deformed leaf growth that their feeding has caused
Andrew Johnston@andrewjohnston.bsky.social · last yr.

Today I watched this potter wasp cut apart a leaf (Paranocistrocerus perennis?). I was trying to figure out what it would do with the leaf before I realized it was pulling out the caterpillar inside that had tied it shut!

A black potter wasp with yellow markings uses its mandibles to rip holes out of a leaf. An out of focus white blob can be seen inside one of the holes, foretelling why the wasp is doing this work.The wasp works its way over the leaf, feeling with its antennae into one of the holes it cut into the leaf.The wasp has pulled its head back from the leaf and has a white caterpillar in its jaws.The wasp has a tight grip on its caterpillar prey and has crawled to the end of the leaf from where it is about to take off and provision its young with this parasitized meal.
Andrew Johnston@andrewjohnston.bsky.social · last yr.

This is the European Shot-hole Borer (Anisandrus dispar) that came in a sample of Japanese Maple stems. This female hasn't laid eggs yet and can be really difficult to get out of her gallery if you don't split the stick correctly. Glad I took a Bark Beetle ID Workshop last week to figure this out!

A pitch black ambrosia beetle sits in her T-shaped gallery that she chewed through a Japanese Maple branchA black beetle with reddish legs and antennae, about 4 mm long, is crawling along a split branch after being rudely interrupted in excavating a gallery to raise her young within.The posterior end of a black beetle sticks out of a hole chewed into the crotch of a tree branch. The beetle is trying to get back in to her gallery to hide from any would-be predators.The bumpy black thorax and top of the head of an ambrosia beetle closes off her gallery. Predators or other invaders to her gallery will have a tough time getting past her tightly wedged body which is plugging the hole to the rest of her gallery.
Andrew Johnston@andrewjohnston.bsky.social · last yr.

Some days I get to play the "is it a bed bug" game as an insect diagnostician. Today, our client was fortunate enough to submit an Eastern Bat Bug - Cimex adjunctus. The fringe of long hairs on its prothorax (just behind the head) which are longer than the eye separates this from the common Bed Bug.

A reddish oval insect is sitting on a white background with legs and antennae oustretched. The body is outlined with a fringe of long, stout hairs and the surface is covered in strong punctures. The tail end of the abdomen has a dark blotch within which is the remnants of a former blood meal for this bat bug found inside an Indiana home.A reddish brown bug is looking towards the camera with its legs and antennae outstretched. The body texture is dotted with deep punctures.
Andrew Johnston@andrewjohnston.bsky.social · last yr.

Its almost impossible not to find these fire-colored beetle larvae under bark of a nice rotting log. But the adults never seem abundant to me. This is probably Dendroides canadensis and has a few more molts to go before pupating.

A creamy-yellowish and almost translucent beetle larva is sitting on a dead log where the bark has just been removed. The head bears hardened reddish mandibles, digesting wood and fungi are visible in the gut and appear as a long black tube through most of the insect's body. The hind end of the larva is hardened into a reddish plate with two long cickle-shaped points.
Andrew Johnston@andrewjohnston.bsky.social · last yr.

The golden goatee of this darkling beetle always makes me chuckle. What's it for?? Alobates barbatus and its fancy facial hair can be found throughout the eastern United States and co-occurs with Alobates pensylvanicus that looks almost identical, except for lacking this tuft of setae.

Head of a dark black beetle from the side, with a dense tuft of golden hair just underneath its chinUnderside of the head of a black beetle showing a dense tuft of golden setae on its lower lip (called the mentum).
Andrew Johnston@andrewjohnston.bsky.social · last yr.

This is the Peanut Beetle (Ulomoides dermestoides) that is a cosmopolitan stored product pest. It isn't reported as established in the US, but you can buy colonies as pet food from multiple places online. These things reproduce like crazy in a neglected mason jar with some peanuts!

adult darkling beetle on white background, pitchy black with dark reddish highlights. Ulomoides dermestoides, or the Peanut Beetle or Cancer Beetle.An adult Peanut Beetle on the inside of a peanut shell looking out at the world with its antennae outstretched.a late instar beetle larva that is banded in darker and lighter colors of orangey-yellow with the tip of the abdomen coming to a pointAn early instar Peanut Beetle larva that is creamy white with orangish bands and only slightly hardened mouthparts. It is sitting amongs pieces of peanut debris