March Mammal Madness

#2026MMM WILDCARD
EMOJI BATTLE RESULTS
🦴🆚💉:
🦴👚🐜/💉👚🐜/
🦴👀🐜/💉👀🐜/🦴💥💉/
💉🗡️💀/💉🗡️🦴/💉🍽️🥣/
🏆💉

Image shows the MMM bracket with Assassin Bug winning the Wildcard over the Bone Collector Caterpillar and a checkmark indicating the Wildcard category has been completed.

#2026MMM WILDCARD WINNER:
Assassin Bug!

Join us Wednesday, March 11th at 8PM EST for ROUND ONE of MONEY MAMMALS!

Bayesian consensus of Hyposmocoma showing 95% confidence intervals of posteriors . Numbers above branches are Bayesian posterior probabilities (PP) and ML bootstrap values (BP), respectively. Coloured circles indicate microhabitat types and ancestral state probabilities.

Hawaiian Hyposmocoma caterpillars show near-identical “purse case” larval homes, despite evolving independently twice in rotting wood (NW islands ~15–9 Ma, main islands ~3 Ma). DNA phylogeny of 38 spp. reveals convergent design under similar pressures. doi.org/10.3897/zook... #2026MMM
#RIP #2026MMM

An insect faces left carrying the remains of dead ants on its back with a large title "Assassin Bug" across the piece.

#2026MMM #BoneyardDivision #TeamAssassinBug Art by Mary C. Freisner @maryfreisner.bsky.social

Join us Wednesday for Round 1 of the Money Mammals Division! Until then be safe, be well, be active! #2026MMM

a group of people are standing in a line with their hands on their head . Alt: A crowd celebrate an awesome outcome.

ASSASSIN BUG DEFEATS BONE COLLECTOR CATERPILLAR and becomes the #16 seed of the THAT'S SO METAL DIVISION OF MARCH MAMMAL MADNESS!!! #2026MMM

leaving behind a new camouflaging caterpillar skin suit for the Assassin Bug to don! (Brandt & Mahsberg 2002)

#2026MMM

The injected enzymes from the Assassin Bug begin DISSOLVING the Caterpillar's insides to be slurped up...

(Brandt & Mahsberg 2002) #2026MMM

PHWOOOOT!!! ASSASSIN BUG PLUNGES PROBOSCIS INTO THE CATERPILLAR.... #2026MMM

Side-stepping the NOT WEAKENED INSECT PREDATOR,

Bone Collector Caterpillar wasn't counting on something putting up a fight!!!

#2026MMM

THE ASSASSIN BUG PLUNGES ITS ALMOST-INSTANTLY-PARALYZING-SALIVA-INJECTING-PROBOSCIS INTO THE ALREADY DEAD ANT HEAD...

MISSING THE CATERPILLAR!!!

(Brandt & Mahsberg 2002) #2026MMM

The two CARCASS-COVERED insects collide and

PHWOOOOT!!!

#2026MMM

The Assassin Bug is drawn to the prominent ant head attached to the Caterpillar... ants are the most preferred meal!

#2026MMM

The Bone Collector Caterpillar is drawn to the ant carcasses on Assassin Bug... another easy meal!

#2026MMM

Figure 1 Two juvenile Acanthaspis petax: one without (left) and onewith (right) a mask constructed of ant carcasses. Journal of Zoology 273 (2007) 358–363 The Zoological Society of London 359Bugs with backpacks deter vision-guided predationR. R. Jackson and S. D. Pollard

From the darkness comes... the nymph ASSASSIN BUG...

arrayed with an even greater corpse cape,

the 4mm Assassin Bug has attached several ant corpses to its abdomen with "fine adhesive threads that the bug secretes from its abdomen" appearing much bigger!

(Jackson and Pollard 2007). #2026MMM

Fig. 1. Pinned adult female (left) of the bone collector caterpillar and portable case (right) in which the larva resides decorated with body parts from ants, bark beetles, weevils, and flies. Unlabeled parts are all host spider integument that has been shed. Rubinoff et al., Science 388, 428–430 (2025) 25 April 2025

Bone Collector Caterpillar has been decorating its 5mm body with a hodgebodge of insect body parts...

with an ant head and leg, fly wing, bark beetle abdomen, and weevil head, precisely sized, positioned, and woven to cover the caterpillar's body

(Rubinoff et al. 2025) #2026MMM

But Bone Collector Caterpillar lost the home habitat coin toss and #MMMagic translocates the Lepidopteran to Comoe´ National Park (CNP), Ivory Coast, West Africa #2026MMM

Fig. 2. Rotting wood log broken open to expose a bone collector caterpillar resting on a clump of webbing next to a non-native spitting spider (Scytodes sp.) with its egg sac. The web is partially obscured by termite and other wood-boring insect frass. Rubinoff et al., Science 388, 428–430 (2025) 25 April 2025

TONIGHT... on O'ahu, Bone Collector Caterpillar prowls the web of a spider, chewing through the silken web to reach the weakened, dying, & dead spider prey for an easy opportunistic meal (Rubinoff et al. 2025) #2026MMM

a man playing a guitar with the words " are you ready for the most metal concert in the history of the world " below him Alt: a man playing a guitar with the words " are you ready for the most metal concert in the history of the world " below him

BOTH of these combatants are in their MOST METAL MORPH in MARCH!!!

(Rubinoff, personal communication; Brandt & Mahsberg 2002). #2026MMM

a man in a suit and tie is sitting in front of a river and says `` oh yeah , just one more thing ... '' Alt: Columbo says "Oh yeah, just one more thing..."

And yes, we know what you're wondering... #2026MMM

Best Reduviinae tree based on RAxML analysis of 178 taxa using a partitioned molecular dataset of 5 gene regions (16S, 18S, 28S D2, 28S D3–D5, Wg). Bootstrap values are indicated on branches by colored triangles according to support strength. Reduviinae lineages are indicated as red branches and remaining reduviids as blue while outgroup taxa are black. The shaded red box highlights members of the hematophagous Triatominae, here shown as paraphyletic. Red arrowheads refer to the polyphyletic Cetherinae; the asterisk refers to Physoderinae nested within a reduviine clade.

The subfamily Reduviinae (Assassin bugs) is a taxonomist's nightmare. A molecular phylogeny done by Hwang & Weirauch (2018) reveled it is polyphyletic, meaning the group doesn’t share a single recent ancestor. doi.org/10.1371/jour... #2026MMM

A large insect, taking over half of the canvas, faces left carrying the remains of dead ants on its back.

#2026MMM #WildCard #TeamAssassinBug Art by Mary C. Freisner @maryfreisner.bsky.social

With a preference for ants, the immature Assassin Bug wears the exoskeleton of its prey as a costume to defend itself against predatory jumping spiders... a tactic called CORPSE CAMOFLAGING (Jackson and Pollard 2007). #2026MMM

And that Yahoo from O'ahu is taking on the better-known baddie ASSASSIN BUG! #2026MMM

Molecular phylogeny of Hyposmocoma lineages based on 38 genes and 82,875 aligned base pairs. 95% highest posterior density confidence intervals for the molecular dating estimates for nodes are indicated with blue bars. Different lineages are indicated by their larval case type, and exemplar cases are shown on the right. Bone collector and cigar case species are the only ones that are carnivorous. Current terrestrial areas of the Hawaiian Island chain are shown in dark green; shallows that were once above sea level are shown in gray. The islands are placed along the timescale according to age and geographic position.

Bone collector caterpillar (Hyposmocoma) comes from one of Earsth's most diverse adaptive radiations with 350+ Hawaiian spp. Phylogenomics finds 9 major lineages. Yet this one is monotypic (no sister species), split from its carnivorous relatives >5M years ago. DOI: 10.1126/science.ads4243 #2026MMM

A grey caterpillar is nested on a spiderweb, covered in armor made of the remains of dead insects.

#2026MMM #WildCard #TeamBoneCollectorCaterpillar Art by Mary C. Freisner @maryfreisner.bsky.social

4x the search traffic for the species after being included in MMM than when it was covered in the NYT, CBS, NPR, etc.

But can we talk about that "Bone Collector Caterpillar" March Mammal Madness bump? #GoogleSearchTrends #DustsShouldersOff #2026MMM

Very hungry caterpillars are almost ALWAYS vegetarian... but not tonight's combatant! Out of ~200,000 butterfly & moth species, Bone Collector Caterpillar is one of the 0.2% that seeks MEAT. (Rubinoff et al. 2025). #AintNoHerbivore #2026MMM

Meet the hungry caterpillar's punk cousin — the 'bone collector' A newly discovered species of caterpillar eats other bugs and then wears their dead bodies.

Hailing from Hawaii, if you are just now learning about Bone Collector Caterpillar, that's because it was first described to science in late April 2025, literally in the journal SCIENCE! (Rubinoff et al. 2025) #2026MMM www.npr.org/2025/05/01/n...

Stylized "wild card" cards of both insects wearing their corpse suits (described in coming battle).

FIRST & ONLY UP TONIGHT: Bone Collector Caterpillar (Hyposmocoma) vs. Assassin Bug (Acanthaspis petax) #2026MMM