John Carlson
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johncarlson.bsky.social
John Carlson
@johncarlson.bsky.social
1.5K followers 1.2K following 760 posts
Allergist/Immunologist, Entomologist/Parasitologist, Pediatric Residency Director at Ochsner in New Orleans. Research, MedEd, Insect macrophotography
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johncarlson.bsky.social
Late September is when green leaves turn into yellow butterflies here in New Orleans.
A bright yellow butterfly is seen in profile sitting on a pale yellow flower. The sun’s angle sets off the texture of the wings with shadows under the veins.
September 27, 2025 at 10:41 PM
johncarlson.bsky.social
A pale-legged flea beetle, Lysathia ludoviciana, looking contemplative at the leaf’s edge.
A black beetle with a faint greenish hue is at the edge of a bright green leaf. You can see plant hairs on the bottom of the leaf giving you the sense that this is really zoomed in to a tiny beetle. The beetle is peering over the edge of the leaf.
September 27, 2025 at 3:12 PM
johncarlson.bsky.social
The Bronzed Tiger Beetles (Cicindela repanda) scampering along the Mississippi River beaches have subtle iridescent colors when you look closely.
A brown beetle stands on sand. There are white curly lines on the elytra scribbled in from the lateral margins. When you look closely at the brown parts of the elytra, thorax and head you see red and green iridescent sparkles
September 21, 2025 at 6:49 PM
johncarlson.bsky.social
A Hibiscus Scentless Plant Bug, Niesthrea louisianica, on the edge of a hibiscus flower in the Mississippi River flood plane
A bug with an orange head and body with speckles of white, pink, and maroon, is standing on the edge of a flower petal that is light pink in color. The translucent wings folded over the back of the bug have a hint of orange to them. It is a bit gaudy.
September 20, 2025 at 8:47 PM
johncarlson.bsky.social
Despite the unusually dry weather we had a successful Bug Walk in Audubon Park and nearby neighborhood to find insects of medical (and non medical) relevance. This year we had folks download @inaturalist.bsky.social (or Seek) to practice documenting the biota in the city.
A group of people are standing in front of a fountain with a statue of a woman at the top, seen above the heads of the people standing in front of it. The oldest of the group is a man to the far left wearing brown boots, green pants, a tan shirt, tan hat, and brown tie. That’s me! The Allergy Fellow in the bottom right hand corner is holding an aerial sweep net. A huge live oak tree is in the background
September 19, 2025 at 6:19 PM
johncarlson.bsky.social
What a beautiful insect, and posing so nicely for this photo!
jerrywiley.bsky.social Jerry @jerrywiley.bsky.social · Sep 17
@johncarlson.bsky.social had a visitor last evening on my deck. A Carolina Mantis. Was a good photography subject as he didn’t move at all while I took several shots. #photography #nature
September 19, 2025 at 6:11 PM
johncarlson.bsky.social
Looking back I didn’t upload any photos in 2013; it was when we did a repeat BioBlitz at Jean Lafitte 2016 that I brought a group of Allergy/Immunology fellows and took my first photo. Incidentally that was the start of my annual Allergy Bug walk for fellows.

How it started / How it’s going
A wasp with red head and thorax, black abdomen and wings l, and yellow legs is face-down on a green leaf A wasp with red head and thorax, black abdomen and wings, and yellow legs is head down on a filmy translucent web with numerous white caterpillars within the nest. Most of these are blurry being inside the web but one has been pulled out and the wasp is preparing it to take back to its own nest
September 15, 2025 at 10:55 AM
johncarlson.bsky.social
My first post on @inaturalist.bsky.social was a Metric Paper Wasp (my favorite paper wasp) as part of a National Geographic supported, invertebrate-focused BioBlitz in Jean Lafitte National Park in 2013. And now it is my 20,000th post also!
A screen shot from the iNaturalist app. In the top left is a tiny photo of me with my son. Below that you can see the species number, 20,000 and to the right on the same line it says 3,250 species. You can see the three most recent posts, a metric paper wasp at the top, the a North American spit-throated grasshopper and lastly a sleepy orange butterfly.
September 14, 2025 at 10:20 PM
johncarlson.bsky.social
It’s very dry here in New Orleans; plants are crisping up and the insect activity is way down. An exception is this wasp, clamoring over flowers, perhaps using nectar for hydration
A wasp is standing on the backside of a stem with little white flowers on it. The flowers are so little that we can see most of the underside of the wasp. The abdomen is light brown with yellow stripes, the thorax black with yellow legs grasping onto the plants, and most clearly you can see the face of the wasp that is light yellow with shiny brown eyes on each side and antennae curing in front of it.
September 14, 2025 at 6:30 PM
johncarlson.bsky.social
I finally got a flash for my camera so that I could increase shutter speed. My first subject was one of the frenetically bumbling bumblebees crashing into flower after flower. I didn’t get a great photo of the bee but you can see the pollen floating away from the flower which is really interesting
A photo of a bee hanging down from the bottom of a white flower. It’s very fuzzy with black and yellow fur. Its tongue is probing into the flower. Off to the left of the bee are little white specks floating in the air, seen on the bah round of blurry green vegetation
September 13, 2025 at 3:07 PM
johncarlson.bsky.social
A pretty Thread-waisted #wasp meandering through the vegetation at Bayou Savage in New Orleans
An insect seen in near-profile. Its abdomen is a reddish brown. Thorax is black and yellow but mostly covered by translucent wings with dark veins folded over the back. The head has large black eyes and a pale yellow face. The black legs are helping to crawl across a background of grass that is green and tan.
September 12, 2025 at 12:41 AM
johncarlson.bsky.social
A Question Mark #Butterfly sipping Mississippi River water on the sandy shores under an exceptionally bright sun this past weekend
A brown butterfly seen in profile on a rough patch of sand. The background of the photo is mostly white, with the bright sun causing the photo to be over exposed.
September 11, 2025 at 2:24 PM
johncarlson.bsky.social
A Four-spotted Pennant #Dragonfly perches next to the Mississippi River as it bends around the city of New Orleans.
September 8, 2025 at 11:21 AM
johncarlson.bsky.social
Hang in there.
A cicada is upside down hanging from a braided metal wire. In the blurry background is a parking lot with cars at the bottom of the image, and above that is a blue sky mostly covered in soft clouds that are white and gray
September 6, 2025 at 8:52 PM
johncarlson.bsky.social
Exploring Bayou Savage in New Orleans East I found this weevil posing on the beautiful backdrop of a flowering Saltmarsh Mallow.
August 31, 2025 at 10:16 PM
johncarlson.bsky.social
This afternoon I discovered that my boots are no longer waterproof but that they remain mosquito proof. Tested simultaneously by water in the Mississippi River flood plane and by several Psorophora columbiae mosquitoes that live there.
A macro photo looking into the face of a mosquito with dark brown shimmery eyes, head and thorax that are various specked colors from dark brown to white, legs sticking out to either side with similar spatter colors of brown and white. It is sitting on a brown fabric driving its proboscis into the fabric.
August 24, 2025 at 10:04 PM
johncarlson.bsky.social
An Anchor Stink Bug instantly before it took flight. Photo taken last weekend on the shores of the Mississippi River.
A close up photo of a black insect with orange spots seen in profile. Its head with long pointy proboscis is pointed downwards relative to the rest of the body. It is sitting awkwardly on the small top leaves of a plant.
August 22, 2025 at 10:51 PM
johncarlson.bsky.social
Two large halictid #bees (I think Nomia nortoni) enjoying some midday sun.
Looking down onto a plant with radiating light green leaves. On two of the leaves there are black bees with bright white abdominal stripes. They are both facing towards the center of the plant.
August 22, 2025 at 4:29 PM
johncarlson.bsky.social
#EntomologyConsult: a patient has an enlarging, progressively itchy, edematous area on her forearm with similar lesions on skin not typically covered by clothes. Bedbug inspection found no insects. This is atypical of her mosquito bite reactions. What could have caused this?
Mostly out-of-focus photo of an arm that has a somewhat reddish swollen part in the middle of the frame. Within the center there is some very mild tearing of the skin from scratching.
August 22, 2025 at 4:23 PM
johncarlson.bsky.social
#EntomologyConsult: a child was stung on the hand by an ant, but with pain beyond what is expected for a typical fire ant sting. Is this species more dangerous? My answer ⬇️
A dead insect curled up. It is red with black markings, slightly out of focus. You can make out the long thin stinger protruding from the tip of the abdomen.
August 21, 2025 at 3:50 PM
Reposted by John Carlson
pauljagriti.bsky.social
Had the privilege of leading Pediatric Grand Rounds at Ochsner Children’s last week. Presented a preterm case that turned out to be a real zebra—a high-grade bowel obstruction from congenital adhesive bands in a 33-weeker. Not your “bread & butter” NICU day.
#NICU #Neonatology #Pediatrics
August 18, 2025 at 6:17 AM
johncarlson.bsky.social
A soldier #fly, Hoplitimyia mutabilis, resting under the hot summer sun near the Mississippi River
A profile view of a black fly, with yellow bands on the posterior abdomen, orangish wings folded over the back, and eyes that are dark green striped with black lines.
August 18, 2025 at 12:21 AM
johncarlson.bsky.social
Happy bees! I wonder if Hibiscus flowers may be too much of a good thing for bees. They can get plastered with the sticky balls of pollen! Hibiscus plants grow wild along the Mississippi flood plane and I can spend a lot of time watching these goofy insects coating themselves in the copious pollen.
August 16, 2025 at 4:56 PM
johncarlson.bsky.social
I’m not particularly superstitious but on days that I do especially high risk protocols in the allergy clinic I wear ties that have ladybugs, a symbol of good luck. Today I wore my ladybuggiest tie and am pleased to report that things went well!
A shiny red beetle with five visible black spots and a black pronotum and head with smaller white spots is sitting on a green leave that as tufts of white fluff on it. Looking closely you can see a small brown aphid being eaten.
August 15, 2025 at 4:42 PM
johncarlson.bsky.social
We had one potential case of locally acquired Chagas’ disease in New Orleans: infected bugs were feeding indoors on someone then diagnosed with infection. Even then it’s uncertain if she got it here vs earlier in life in another country. How do dogs handle it? pmc.ncbi.nlm.nih.gov/articles/PMC...
August 8, 2025 at 7:20 PM