Tessera

Check out this extraordinary female Eucelatoria sp (Tachinidae). She possess a sharp piercer that she tucks up underneath her when not being deployed, for oviposition - you can see her ovipositor nestled in this penetrating sheath! Badass lady! @dipteracourse.bsky.social #FlySchool2026

Not only are #Periscelididae very cute, some of the less spectacular-looking spp. are hypnotic dancers 💃🕺 #Stenomicra shuffles back & forth, easily gliding across surfaces. This large genus is found in the tropics often on banana leaves, etc. #FlySchool2026 Costa Rica 📽️: Nolan Lake [more ⬇️]

OK I thought Scutops was cute, but OMG #NEOscutops is amazing! 😍 I'm now convinced #Periscelididae is, per species, the weirdest family of flies (more evidence from another genus to drop later). #FlySchool2026 Costa Rica [And yes, @americanbeetles.bsky.social, it's cool partly because of beetle]

🐙🦑👁️one-eyed Guy enjoyer @toldentops.bsky.social · 2mo ago

Back in civilization after 2 weeks in the Costa Rican jungle. It was an amazing experience full of spectacular flies (+other creatures) as well as a truly wonderful group of students & instructors. The memories made will last a lifetime. ☺️ 🥰 Can't wait for the next #Diptera adventure! #FlySchool2026

frit fly (Chloropidae: Acanthopeltastes) A small shiny black fly sits on a white backgroundfacing the viewer. Its wings are spread and it has four large spines coming out of the rear of the thorax.

mantis shore fly (Ephydridae: Ochthera) A grayish black fly with large mantis-like forelegs sits on a white background facing left.

horse fly (Tabanidae) A golden brown fly with a huge head made up of mostly eyes sits on a white background facing right, waving its front legs out.

stilt-legged fly (Micropezidae) A thin black fly with long legs and a bright red head and striped eyes sits on a white background facing right, waving around its front legs.

Drawings based on specimens I collected during my costa rica trip! Featuring Ropalomeridae, Richardiidae, and Tabanidae #flyschool2026 #art #entomology

OK I thought Scutops was cute, but OMG #NEOscutops is amazing! 😍 I'm now convinced #Periscelididae is, per species, the weirdest family of flies (more evidence from another genus to drop later). #FlySchool2026 Costa Rica [And yes, @americanbeetles.bsky.social, it's cool partly because of beetle]

A small round beetle-like fly with a shiny black body and bright red head walks on a leaf. Dorsal view.

A small round beetle-like fly with a shiny black body and bright red head walks on a leaf. Lateral view facing left.

A small round beetle-like fly with a shiny black body and bright red head walks on a leaf. Lateral view facing right.

A small round beetle-like fly with a shiny black body and bright red head sits on a white background. Lateral view facing left.

Officially the cutest fly I've ever seen 🥰 😍 It was a target genus of mine & Ezra Bailey was kind enough to save her live specimen for me to photograph [we've been lucky to see more since]. They mostly run around rather than fly. SQUEEEEEEE!!!! #Periscelididae: #Scutops #FlySchool2026 Costa Rica

A small dwarf fly sits on a leaf facing right. It has a yellow stripe down its back and dark wings folded over the abdomen like a little beetle. Its face is pointed into a small whit blunt nose. It's eyes are red with a couple light stripes.

Heads up folks Some Tabanidae that were sampled from the Canopy Tower at the Soltis Center, Costa Rica These images show both differences in eye patterns & antennal branching. Sadly the eye patterns disappear as they desicate so images are important #FlySchool2026 @dipteracourse.bsky.social

OK class: which is the male (♂️) and which is the female (♀️)? [BTW - these are the smallest members of this family of flies I have ever seen!] #FlySchool2026

Two small dark gray flies, one on top of the other and mating, rest on a green leaf.

Close up of two small dark gray flies, one on top of the other and mating, rest on a green leaf.

A rather lovely male Artemita sp (Stratiomyidae), one of the larger Pachygastrinae in Costa Rica. This genus mostly has species with hairy eyes, and this one is no exception @dipteracourse.bsky.social @dipterists.bsky.social #FlySchool2026

Gold star for this silver soldier #fly 🌟 Diptera are seriously amazing 🤩 🥰 #Stratiomyidae: #Artemita argentea Soltis Center, Costa Rica @flygirlnhm.bsky.social @dipteracourse.bsky.social @riccardi-p.bsky.social

A fly covered with thick silver fur sits on a white background facing left. It's head is mostly red eyes with darker red squiggles, and it's wings are held out folder over each other sticking out the rear.

A gorgeous new family of flies for me - Xylomyidae, the Wood Soldier flies These have been poorly studied as most caught via malaise but Antoine Touret hand caught this off a wall at the @soltiscenter. 3spp described in Costa Rica but many more waiting to de determined @dipteracourse.bsky.social

Sometimes you've gotta go metallic to mimic your model! This common tropical hover #fly at the top is a convincing mimic of the local orchid #bees in the genus #Euglossa (bottom). #FlySchool2026 #Syrphidae: #Ornidia obesa Soltis Center, Costa Rica

Two metallic green winged insects on a white background, one at the top and one at the bottom. The top one is a hover fly and the bottom is an orchid bee.

Some crane flies in the genus #Geranomyia produce a little gel nursery to develop on leaves in the tropics. There they graze on algae & other organic matter. The mass provides moisture (other spp. live in water/soil) & likely protects from predators. #Tipulidae #Limoniidae #FlySchool2026 Costa Rica

A jelly mass on the midrib of a long leaf contains a long translucent larva within

A close up of a long, worm-like, translucent larva curving around inside a clear jelly mass

A thick jelly mass on a leaf surface has a long crane fly pupa suspended within

Two greenish crane flies with long beaks mating on a leaf. The female is resting above, while the male contorts himself underneath, connected by their genitalia.

Check out these flies! . . . And of course the amazing eyelash viper 😜 😂 🥰 #Ceratopogonidae #Viperidae: #Bothriechis supraciliaris #FlySchool2026 Costa Rica

A close up of a brown eyelash viper face showing a few blood-feeding biting midges.

A small brown viper wrapped around a small twig, facing down.

The mint chocolate chip flavor of flies [I imagine] 😋 #Stratiomyidae: #Promeranisa #FlySchool2026 Costa Rica

A fly stands on a white background facing right. It is mint green with brown stripes on the thorax and a pointed face with long thick antennae.

Fly School @dipteracourse.bsky.social · 2mo ago

Officially the cutest fly I've ever seen 🥰 😍 It was a target genus of mine & Ezra Bailey was kind enough to save her live specimen for me to photograph [we've been lucky to see more since]. They mostly run around rather than fly. SQUEEEEEEE!!!! #Periscelididae: #Scutops #FlySchool2026 Costa Rica

Collected by @khong-a-tach.bsky.social

The hammerhead condition has evolved numerous times in flies, resulting in various flavors. Last time we found an extreme one (flic.kr/p/2qeN7Hz) but this example is a bit more tame (still lovely, though! ❤️) [Coll.: Khong Lunaria] #FlySchool2026 Costa Rica #Richardiidae: #Richardia cf. telescopica

A yellow and brown fly sits on a white background facing to the right toward the viewer. It has a broad and somewhat triangular head, about twice the width of the thorax.

A female Physoptera (Phoridae) showing off/advertising her presence, by releasing pheromones through her abdominal glands (the yellow stripes on her abdomen). As you can see they have reduced abdominal plates (tergites) that allow these glands to expand #FlySchool2026 @dipteracourse.bsky.social

Fly School @dipteracourse.bsky.social · 2mo ago

The hammerhead condition has evolved numerous times in flies, resulting in various flavors. Last time we found an extreme one (flic.kr/p/2qeN7Hz) but this example is a bit more tame (still lovely, though! ❤️) [Coll.: Khong Lunaria] #FlySchool2026 Costa Rica #Richardiidae: #Richardia cf. telescopica

A yellow and brown fly sits on a white background facing to left. It has a broad and somewhat triangular head, about twice the width of the thorax.

A yellow and brown fly sits on a white background facing away from the viewer. It has a broad and somewhat triangular head, about twice the width of the thorax.

😍

Matt Bertone @bertonemyia.bsky.social · 3mo ago

Gold star for this silver soldier #fly 🌟 Diptera are seriously amazing 🤩 🥰 #Stratiomyidae: #Artemita argentea Soltis Center, Costa Rica @flygirlnhm.bsky.social @dipteracourse.bsky.social @riccardi-p.bsky.social

Spectacular catch on the 1st day of #FlySchool2026 by student Sangjin Han! This massive timber fly was flying around the lobby of the Soltis Center last night. At over 2"/5 cm this is the largest live fly I've ever seen 😳 Larvae bore in wood. Amazing! 🥰 #Pantophthalmidae: #Pantophthalmus Costa Rica

A large brown fly with yellow-tipped legs and pointy orange antennae sits facing right on a white background.

A large brown fly with yellow-tipped legs and pointy orange antennae sits facing right on a white background. A human finger is resting above it to show the large size.

A large brown fly with yellow-tipped legs and pointy orange antennae sits facing toward the viewer on a white background.

Dipterists Society @dipterists.bsky.social · 2mo ago

If you're enjoying these posts (and #flies 🪰 in general) please visit our website: dipterists.org You can become a member and find out how you can join Fly School in the future. We'd love to see you!

Sometimes you've gotta go metallic to mimic your model! This common tropical hover #fly at the top is a convincing mimic of the local orchid #bees in the genus #Euglossa (bottom). #FlySchool2026 #Syrphidae: #Ornidia obesa Soltis Center, Costa Rica

@bertonemyia.bsky.social asked his seven year old nephew to give common names to flies.. Do you agree? And can you name the actual families? #FlySchool2026 @dipteracourse.bsky.social @dipterists.bsky.social

Afternoons lecture by Brian Brown at @dipteracourse.bsky.social #FlySchool2026 starts with Hypopygial circumversion in the higher flies Instead of the males being dragged along, their genitalia has rotated to offer them some dignity 🤓🤘

Lots of ‘whooping’ about the next lecture at #FlySchool2026 by @riccardi-p.bsky.social - genitalia preps ‘We use genitalia as its under positive selection’. @dipteracourse.bsky.social

Just a couple big-headed flies making more big-headed flies, which I appreciate so I can see more big-headed flies 😁 #Pipunculidae #FlySchool2026 Costa Rica [PS: Jim Hogue is about to wow us w/these flies & their close relatives the hover flies!] @flygirlnhm.bsky.social @dipteracourse.bsky.social

Two big-headed flies mating, the male on top of female. They on the end of a small twig with a black background and are facing right. They are dark, with evenly-spaced light gray patches on their abdomen. Their heads are massive and made up mostly of the eyes.