It has been months since my last post, and I’ve missed the process of researching, writing and illustrating my natural history chronicles. This post is inspired by some chance encounters as well as one of my domestic passions. I hope you’ll enjoy this post as much as I have enjoyed putting it together.
One night while washing my face at bedtime, I perceived a dark movement on the tiles close to the bathroom sink. “A centipede”, I thought at first. “No, it is something else. It looks familiar.” Before I captured the 15-cm creature with toilet paper and carried it carefully to the garden, I took a photo. It wasn’t until after I released it that I recalled the name of this rare predator, the velvet worm—a relict, a living fossil.
My former husband, the late Luis Diego Gómez, had found such a creature in 1999 at Las Cruces Biological Station here in San Vito and sent it to our friend at the University of Costa Rica, Dr. Julian Monge Nájera, ecologist and evolutionary biologist. He identified it tentatively as Epiperipatus geagi, the white collared species of velvet worm known in Panama but not previously discovered in Costa Rica. So this appeared to be evidence of an extension of its range. It was this same species that I found in my bathroom. Now, after receiving my photo at the left, Julian tells me that the species taxonomy is undergoing revision and is soon to have a new name, so we will call it for now Epiperipatus sp.
While it is not exactly a charismatic creature (although students of zoology would disagree!), the velvet worm has a distinguished history of longevity and remarkable evolutionary adaptations. Dr. Monge Nájera believes they were probably the first animals ever to walk on our planet. According to fossils from Yunnan, China, velvet worms emerged from the shallow pools of Cambrian seas 530 million years ago to walk on land amidst algae and later, soils. The marine species went extinct. Now velvet worms are found only in humid areas of Australasia, southern Africa, and parts of Central and South America. Unusual for such a small invertebrate, they can live up to seven years!
Velvet worms are in the phylum Onychophora (on-ick-OFF-ora): elongated, multi-legged, and soft-bodied worms. Today there are 197 formally described species of Onychophora on earth, and there are likely many more unknown to science. They are nocturnal and frequent humid, dark environments like decaying logs in the rainforest, non-compacted soil crevices, leaf litter and moss-covered tree trunks. When the slow and soft velvet worm encounters a small crustacean, insect, or spider, the worm has a spectacular, Marvel-comic like way of capturing its victim.
From a pair of oral glands, it ejects–in firehose fashion from inches away–adhesive, silk-like threads, whose strands quickly harden while remaining sticky. The strands dry enough to imprison and essentially paralyze the prey. The velvet worm then approaches and injects its digestive saliva, and while the victim dies, the velvet worm eats the sticky strands, recycling its own nutricious proteins. Finally, the content of the prey’s body is eaten using sickle-shaped mandibles. Such a successful strategy explains this animal’s perseverance on earth in largely the same form through the eons.
Because velvet worms are exceedingly rare, to have one appear in the bathroom seems like a felicitous honor. If anyone receiving my post should in the future find a velvet worm, I’m sure Julian and his students would be very pleased to receive a photo and report. Contact me and I will put you in touch, or find Julian in the biology department at UCR.
On the day in early 2017 that I met Rebecca Cole, tropical ecologist and the new director of the Las Cruces Biological Station, an Organization for Tropical Studies site where I worked from 1989 to 1999, we took a walk around the grounds, just 2.5 k from Finca Cántaros where I live today. Suddenly I spotted a fast moving insect running along the edge of the path, a large ant with unusual coloration. Aha! It was the velvet ant which is not actually an ant at all, but rather a large female wingless wasp in a family of Hymenoptera called Mutillidae. I had seen one years before. It is quite rare to find a female, and even more unusual to observe a velvet ant in daytime–they are generally nocturnal.
The velvet ant has about 3000 described species, and is so named because of dense body hair. The hair may be scarlet, orange, gold, silver, black or white. Body parts of some species are very brightly colored.
I’m glad I didn’t try to pick up the velvet ant to photograph it better, as I’m apt to do with certain other insects. Females of these wasps have impressive stingers (males are harmless), and some species are known as “cow killers”. The pain their sting delivers for up to thirty minutes to humans is described as a “pray for death” kind of pain; so while the velvet ant really can’t kill a cow, the epithet is understandable!
Velvet ants feed on larvae and adult insects such as bees, beetles, flies and other wasps, as well as nectar. The Mutillidae are known for their Müllerian mimicry*, a form of protective imitation in which the mimicking animal is as inedible or disagreeable to predators as the animal it mimics.
A red velvet cupcake won’t walk, run or slither across your plate, but does slide pretty easily down your gullet. I found a recipe for naturally colored and naturally sweetened velvet cupcakes. It is easy to use beets for the coloring. You might like to try these when that urge for sweetness calls. And there are many Red Velvet Cake recipes out there if cupcakes aren’t your thing.
Until next time, keep your eyes open for the unexpected…!
* The zoological term is named after Fritz Müller, 1801-1897, a German naturalist.
Onychophoran online by Julian Monge-Nájera.
White-collared Stickers, by Julian Monge-Nájera, Amigos Newsletter, Wilson Botanical Garden, April, 2000.
The Smaller Majority by Piotr Naskrecki, The Belknap Press of Harvard University Press, Cambridge, Massachusetts; London, England, 2005, p. 37.
Velvet Ant in Wikipedia.