Andrew Warren

@andybugguy.bsky.social

2360 Followers 241 Following

IN AWE OF NATURE! Entomologist, systematist, biogeographer, photographer; museums & collections. Based in Colorado! he/his. My science: https://lepscience.com/my-publications/

Bristly blackish caterpillar with orangish highlights, in the palm of my hand. This is an undescribed species… I’ve been rearing this and its ~200 siblings, with good success so far. I hope they beef up and make cocoons soon, otherwise I might have to figure out how to overwinter them…
Butterfly feeding at sap on a thick branch, fluttering its wings open and shut, with ants running around its legs. The upperside is orange with black and golden spots, while the underside is a cryptic dark grayish striated pattern that blends in with the tree trunks it perches on. The bright white legs are characteristic of the Oreas Anglewing from the Pacific Northwest to Colorado. I wonder, why don’t the ants attack the butterfly legs? Instead, they run right around them…
Mountain meadow looking up to 14,000’+ peaks.
View of West Spanish Peak- blue sky forever and a mountain of rocks
These tiny, hairy, pinkish caterpillars are stationary, and not feeding at the moment- all are about to shed their head capsules and skin and turn into bigger, far more efficient eating machines! It’s so exciting to see the immatures of this undescribed species, still new to science!
The pattern of black markings on the white background of this moth give it a remarkably cryptic and unique appearance. This undescribed species is known as "Hypsocompe extrema of authors" on the Moth Photographers Group website, where it is acknowledged as an undescribed species known from Arizona and Texas. There are known specimens from New Mexico as well, and in 2022, Christian and I found the first record in Colorado- in Baca County. This one, from Huerfano County, pushes the known range of this rarely encountered moth even further north... Huge thanks to Chris Pague and Michael Figgs for arranging access to the site!
Old schoolhouse on shortgrass prairie at the junction of Huerfano County roads 120 & 103, with the Spanish Peaks in the background.
Large colorful moth with a maroon-and-white striped body at rest below UV lights, on a cool morning in Castle Pines, Colorado. The season is WAY ahead of schedule!
Old schoolhouse in Huerfano County, Colorado, northeast of Walsenburg. Wet Mountains in the background.
This female moth cannot fly. She has wings, but they are not fully developed (called brachypterous). Females of this species require warm bare ground and stubby grass to be active during their late October-late November adult emergence. Currently known habitats are regularly mowed. Before the evolution of lawn mowers, we speculate that their specialized habitat was maintained by grazing and movements of large mammals such as bison, pronghorn, elk, deer, and prairie dogs. Females lay 250-400 eggs near the bases of highly disturbed Sand Dropseed grass. When larvae eclose in the spring, they immediately burrow down into bases of the grass clumps, and they apparently develop underground feeding on the roots of Sand Dropseed. While described from and currently only known from Colorado, we suspect this species will be found to occur elsewhere once targeted searches are conducted. Perhaps additional species in this genus will be found? Unidentified observations at iNaturalist helped us find additional populations once we knew what to look for. Several males and one female were found there, as cited in the paper linked in this post. They are now identified at iNaturalist as Coloradactria frigida.
Mountain Ball Cactus, Pediocactus simpsonii, in dappled light from full cloud cover. Pink and Yellow flowers appear in a different hue than in full sun, as was the original photo. E of Castle Rock, Douglas County, Colorado, 28 March 2025.
The Mountain Ball Cactus is widespread in Colorado at elevations above 6000'. They bloom very early in the spring. This one, with bright pink and yellow flowers, was found on March 28, 2025, east of Castle Rock, Douglas County, Colorado. These cactus don't usually bloom quite this early in the season, but we had very warm weather in late March. Spring is here!
Yellow and black butterfly with blue and red spots on the hindwing, basking on the arctic tundra of Alaska's North Slope. Papilio machaon is called "The Swallowtail" in Britain, where it is the only resident swallowtail species. In North America, it is usually called the Old World Swallowtail.
Small brown moth with irregular grayish and white markings, at rest on a wall near a Polistes wasp nest. The carnivorous caterpillars can completely decimate a wasp nest over the course of the summer.
Brown butterfly with white spots and irregularly-shaped red patches near the center of the wings. This butterfly is thought to be a Batesian mimic of toxic butterflies such as Heliconius.
Large black and white butterfly with long silver-edged tails fluttering around the larval foodplant Pawpaw (Asimina) and dragging her abdomen on its leaves,
This slug-like caterpillar is covered in irregular tubercles and protuberances covered with venomous hairs and spines that can deliver a painful sting.
This shiny black beetle, Mycotrupes gaigei, is endemic to north Florida sandhill habitats, where they make burrows up to 6 feet deep. The tiny flies, Ceroptera longicauda (Sphaeroceridae) are phoretic on the beetles and kleptoparasitize its dung caches. Levy County, Florida, USA
Small greenish butterfly with orange, yellow and white markings. Most of the year the Dainty Sulphur is mainly yellow on the underside, but extreme late-season individuals like this one are mostly greenish instead. This pic is from the same place as today's butterfly but from Dec. 18, 2013; all I got of today's butterfly was a crummy cell phone pic...
Black and white striped butterfly with long tails on the hindwings, ornamented with red and blue spots, and a red stripe near the middle of the hindwing.
Greenish caterpillar with an orange head and transparent skin, showing the fine details of the spiracles and tracheae which serve as its respiratory system.
Two brown butterflies with red and silver markings on the ventral hindwings that resemble jumping spiders.
Orange-red butterfly with black and pale markings, perched on and feeding on the nectar of the bright yellow flowers of Sedum lanceolatum.
Bright orange butterfly perched on white and yellow flowers.
White butterfly with orange and black stripes and short tails on the hindwings.
Tiny orange skipper butterfly with vague white streaks on the hindwing and a whitish belly.
Yellow butterfly with metallic patches of scales surrounded by dark red blotches. Greenish eyes...
Large grayish robber fly (above) with mouthparts inserted into the thorax of a yellow-and-black yellowjacket wasp (below).
large black and pale yellow robber fly feasting on a bee. Robber flies feed by ramming their mouthparts into whatever they can catch, then sucking them dry like a vampire...
Large, cream-colored butterfly with dark wavy patches, brown-black stripes, and three large eyespots- one on the forewing and two on the hindwing.
Hundreds of Painted Lady butterflies (Vanessa cardui) nectaring on Rabbitbrush take flight as a cloud obscures the sun. This swarm was recorded in September, 2017. Video taken with a GoPro.
Large brown butterfly with yellow, blue and orange spots- the Palamedes Swallowtail (Pterourus palamedes)- to the left, with an orange Delaware Skipper (Anatrytone logan) to the right and a brown with white spots Twin-spot Skipper (Oligoria maculata) coming in at the far right.
Bright yellow and orange flowers attracting 4 Anicia Checkerspot butterflies which are red, black, and white.
The Giant Swallowtail (Heraclides cresphontes) is a large yellow and black butterfly with red and blue spots on the ventral hindwing. This male is feeding at flowers of Florida Paintbrush (Carphephorus corembosus). Florida, USA
Vibrant yellow butterfly with black stripes and bluish spots, with proboscis fully extended. This is a popular handrail for tourists, and the butterflies just love feeding on the salts from people's hands...
Green and black butterfly, called the Malachite, resting on leaves in a tropical Brazilian forest.
This small, pink and reddish butterfly was guarding a hilltop perch in southern Brazil.
Male holotype specimen of Pelochrista purgatoriana, from JE Canyon Ranch, Las Animas County, Colorado. Figure shows half of this tiny moth. Forewing pale orange with gray and silver markings; hindwing beige. This species is known from just 3 male specimens, all collected the same night.
Female Red-naped Sapsucker busy drilling sap wells. Douglas County, Colorado, August 2016.
This female hackberry butterfly still has the larval head attached. For whatever reason, when the larva pupated, it could not shed the head capsule, yet she successfully developed into an adult- all but the head! She was found by John Froeschauer in August, 2020, flopping around on his driveway, unable to fly.
Female Cofaqui Giant-Skipper, Megathymus cofaqui, a large brown skipper with yellow and white spots and grayish overscaling below. This individual failed to shed her head capsule when pupating- it was stuck on top of the pupa like a bottle cap. Amazingly, the adult developed normally except it still has the larval head attached! Reared from Citrus County, Florida, USA.
Male Hemileuca magnifica attracted to caged female Argiope aurantia spiders, thinking the spiders are female moths, due to chemical mimicry of pheromones. Costilla County, Colorado
Black butterfly sitting on a lichen-covered rock. This species, Erebia magdalena, is very difficult to approach since traversing its talus slope habitat can be rather treacherous.
This extraordinary gynandromorph is from Popotepe, Veracruz, Mexico, 1979. It resides in the collection of the Instituto de Biología de la Universidad Nacional Autónoma de México.
This specimen is from Covanca, Rio de Janeiro, Brazil, collected on 8 April 1967 by Romualdo D'Almeida. It is housed in the Lepidoptera collection at the Laboratorio de Estudos de Lepidoptera Neotropical, Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.