Lee Weinstein: In Search of the Vegetable Caterpillar

Back when I was a young teenager, I came across an intriguing item in Robert Ripley’s first Believe It or Not! book (1929). The text read “The pepe-aweto of the Maoris. Strangest insect on Earth. A caterpillar that turns into a plant.” It was accompanied by a drawing of a caterpillar with a long stem rising vertically from one end, with some feathery looking branches at the top. Below the drawing the text continued: “Is it an insect or a vegetable?”

As someone who was eventually to become a biology major in college, my curiosity was greatly sparked by the cartoon, but, at the time, I was a 14- or 15-year-old with little in the way of either research skills or reference materials. I did know that Ripley promoted himself as a man who could prove every statement he made, but it wasn’t until years later that I was to discover that Ripley would consider something “proven” if he could point to something in print that provided a source, whether or not that source was reliable. In this case, even though he did not cite a source, I sensed both at the time and later on that the cartoon referred to something quite real.

I put my curiosity aside to make way for other interests, but my memory of it was evoked a number of years later while I was reading a collection of Edgar Allan Poe stories. I came across an intriguing reference in his story, “The Thousand-and-Second Tale of Scheherazade” (1845). This was one of Poe’s humorous tales, and in it the character Scheherazade relates to her king a series of wondrous things seen by Sinbad the sailor. These wonders were all real things that Poe had obtained from contemporary news items and books. Each wonder in the tale was duly footnoted by Poe.

Sinbad describes at one point in the story, “vegetables that derive their substance from the bodies of living animals....” Poe footnotes this with references to certain types of algae. He then goes on to give this quotation:

Mr. J.B. Willians [sic] of Salem, Mass presented the ‘National Institute’ with an insect from New Zealand with the following description—‘The Hotte.” A decided caterpillar, or worm, is found growing at the foot of the Rata tree, with a plant growing out of its head. This most peculiar and most extraordinary insect travels up both the Rata and Perriri trees, and entering into the top, eats its way, perforating the trunk of the tree until it reaches the root, it then comes out of the root, and dies or remains dormant and the plant propagates out of its head; the body remains perfect and entire, of a harder substance than when alive. From this insect the natives make a coloring for tattooing.

This “hotte” was obviously the same organism as Ripley’s “pepe-aweto.” Both were found in New Zealand, and the description in the footnote matched Ripley’s drawing. This confirmed that Ripley was referring to a real creature of some sort. But what was it?

The concept of plant-animal hybrids or organisms sharing aspects of both is one that goes back to antiquity. The mandrake plant was once believed to cry out when pulled from the earth. The “barometz,” or “vegetable lamb of Tartary” is a legendary creature dating from about the eleventh century with roots (no pun intended) going back to Biblical times. In one version of the legend a type of plant generates a small lamb that remains attached to it. In another version, tiny lambs are found within a gourd-like or melon-like fruit. A possible source of the legend is a type of fern from China (Cibotium barometz) with a wooly-appearing rhizome that bears a fanciful resemblance to a lamb. Another possibility is the embellishment, via medieval traveler’s tales, of the cotton plant and its wool-like product.

Real plant-animal hybrids are rare but not entirely unknown to biology. The one-celled organism Euglena is a motile, animal-like protozoan that propels itself through the water with a flagellum, but it also contains chlorophyll-containing chloroplasts. It can feed like an animal or make its own food like a plant when there is sufficient light. A more recently discovered organism is the far more complicated green sea slug. This is a mollusk containing functioning chloroplasts that it obtains by ingesting algae. Once it eats the algae, it can go on producing its own chlorophyll and photosynthesizing its own food.

The idea of such plant-animal crossovers is also the stuff of science fiction. There are, of course, many stories and films about such organisms. The most well known, perhaps is the classic film The Thing (From Another World) (1951). The titular creature is described as a humanoid “vegetable” (although it should be noted that this was not the premise of John W. Campbell’s original story, “Who Goes There?”). There are many other variations on the theme. The film Mutations (1974) posits the creation of human-plant hybrids by a mad scientist played by Donald Pleasence. The novel The Green Man from Space (1954) by Lewis Zarem is about a Martian who is a humanoid-algae symbiote. The algae embedded in his skin provide him with food and oxygen. The Richard M. McKenna story, “Hunter Come Home” (1963), is about a planet-wide plant-like organism with leaf analogs called “phytos” that detach and fly about like insects, transferring information between different parts of the organism.

After reading the Poe story, I asked an acquaintance at the time who was an entomologist and who specialized in moths, butterflies, and therefore caterpillars about the pepe-aweto, but he had never heard of anything like it. He had also never heard of the National Institute. Years later when one was available, I consulted a Maori-English dictionary. There was no entry for “hotte” and none for “pepe-aweto,” but I noted that one of the definitions of “pepe” by itself was moth or butterfly.

From time to time over the years, I would look through books on insects and books on New Zealand looking in vain for the terms “pepe-aweto” and “hotte.” When they became available to me, I checked some online databases in the biology field but to no avail.

I eventually came across an annotated edition of Poe, and the marginal notes added a small bit of information. It told me that the above-quoted footnote from Poe’s story had been taken from the third Bulletin of the National Institute (1845), page 369, and added that John B. Williams was a US consul in Auckland in northern New Zealand. He was appointed consul in 1842.

I consulted with a librarian at a local museum, Philadelphia’s Academy of Natural Sciences. I explained to her what I was looking for and gave her photocopies of the Ripley cartoon and the Poe story.

“What do you think it really is?” she asked.

I shrugged. “Some sort of parasite, maybe? It’s hard to tell from this. That’s why I’m so curious.” At the time there were no multicellular organisms like the green sea slug known, and it was hard to imagine a plant taking root in a caterpillar. It had also occurred to me that I could be barking up the wrong tree, so to speak. That is, this creature or whatever it was might not be an insect at all but merely something that looked like an insect. Maybe it was a plant that had a vaguely caterpillar-shaped part in the way that the barometz was a plant with a part that resembled a tiny lamb. The consul’s description of the caterpillar’s behavior might have been based on hearsay rather than actual observation. It may have been a growth found on tree roots.

If that were the case, it would make further research extremely difficult. If it was a caterpillar, there are reference books on caterpillars. But if it wasn’t, I would have to consult reference books on—what? I tried looking up Rata and “Perriri” (actually Puriri) trees but found nothing.

The librarian took my copies and sent them to their department of entomology.

They were unable to come up with an answer. But she also discovered that her library had the microfilm of the cited journal.

I loaded it into a reader-copier and found page 369. It contained little information beyond what Poe had quoted. It was a list of specimens from New Zealand that Mr. Williams had contributed to the National Institute. But it did tell me that an actual specimen had been contributed to an American museum. That was interesting.

There is no “National Institute” today, but I reasoned that it was probably the predecessor to the Smithsonian Institution and that the object donated by this man or a record of it might still be retained somewhere by the Smithsonian. Not likely after about 150 years but still possible, resting in a glass case or hidden in a dust-covered jar in a storage area. More likely, though, was the possibility that someone on the staff there might be familiar with this organism. So I wrote to them, giving them the citation and asking what the object might have been. About a month later, I received a confirmation that they had gotten my query and that I would be answered in turn when they got to me. I never heard anything further from them. I supposed they must have been stumped too, as was the entomology department at my local natural history museum.

I put the project aside. More years passed. The Internet came into being, and the library where I was employed acquired access. One day, I happened to think of it and typed “pepe-aweto” into a search engine. Nothing came up. I tried “hotte.” Likewise nothing. Then on a whim I broke the terms apart and tried the word “aweto” by itself.

Bingo! In a flash, the mystery was solved. The aweto, I discovered was also known as the vegetable caterpillar or less commonly, the hotete, and it was not limited to New Zealand by any means. It was not an insect, and it was not a tree growth, nor even a plant. In fact, it was a type of fungus, and one with a specialized and highly unusual lifestyle. At the time Poe and Ripley were writing, fungi were classified as part of the plant kingdom. This formally changed only in 1969 after advances in biochemical research showed that fungi were not closely related to the plant kingdom and they were assigned to a kingdom of their own.

The vegetable caterpillar is one of the numerous species of the genus Cordyceps. This fungus is a parasitic organism that infects caterpillars of various species. The spores enter the caterpillar, germinate into a mycelium, and kill the host. The fungus then grows inside the host, consuming its insides, but leaving the outer skin intact. When it has consumed everything but the skin, it sends up a fruiting body from the head to generate more spores. What is left is a hardened caterpillar-shaped fungus with a long fruiting body projecting from it.

There is a common species in China, C. sinensis, which is ground into a powder and marketed as a kind of medicine. It is supposed to increase virility.

The commonest species in New Zealand is C. robertsii, which is found commonly on the North Island, and it is to this fungus that Ripley was evidently referring. It was ground up and used by the Maoris as a pigment and also as a medicine. It generally infects the Porina moth.

This is more the stuff of horror stories than straight science fiction. One of the classic tales of this sort is William Hope Hodgson’s “The Voice in the Night.” (1907). It tells the story of a couple, survivors of a shipwreck stranded on a remote island, which is covered with a strange gray fungus. When their supplies run out, they have no recourse but to consume the fungus. The inevitable results are horrifyingly suggested at the end. The story has been adapted for TV as an episode of the Hitchcock-produced series Suspicion (1958). It was also adapted into the Japanese film Mantago (1963), aka Attack of the Mushroom People.

Hodgson’s story inspired in turn “Fungus Isle,” a novelette by Philip M. Fisher, which first appeared in Argosy in 1923 around the same time frame that Ripley’s cartoon was published. It concerns a group of men shipwrecked on an island covered with an immense forest of contaminating fungal growth that turns men into walking masses of fungus.

“The Voice in the Night” was also a favorite story of Brian Lumley’s, who went on to write “Fruiting Bodies,” about a fungus-infested decaying town on the seacoast and the gruesome fate of an elderly couple who resided there. It won the British Fantasy Award for best short story in 1989.

The posthumously published novella by Edward Lucas White, “Sesta” (2001), is along similar lines. Written circa 1914, a few years before Hodgson’s death, it is about two explorers, deliberately marooned on a South Pacific island, who witness the natives putting prisoners to death by tying them up in the presence of a scarlet fungus-like plant. The following day the living bodies of the prisoners have been replaced by blood-red masses of rootlike fibers, generating tall tubelike stems topped by mushroom-like caps.

Other examples are the Stephen King story “Gray Matter” (1973) and John Brosnan’s novel The Fungus (1985).

The question remained: why had I had such a difficult time finding something that is seemingly commonplace? I had discovered there are species of Cordyceps with similar life cycles worldwide, including North America.

I thought, possibly, the species in New Zealand, C. robertsii, was the first one to become known. There are articles about it in journals dating back to Poe’s day in the mid-1800s.

An article in the California Farmer and Journal of Useful Sciences (11/7/1856) by a Rev. R. Taylor describes the bulrush caterpillar, as he calls it. He describes it as a plant that kills and supplants the body of an insect and notes it is found at the roots of rata trees. He does correctly call it a fungus at one point.

I did some further searching online.

In Kaipara by P.W. Barlow (1888), about northern New Zealand, the chapter on kaipara insects describes what the author calls “the most curious of the New Zealand native insects he has seen, called the bulrush caterpillar (Spoeria robertsia), native name, Aweto.” He goes on to describe it as a caterpillar which changes to “a white vegetable substance while still retaining its caterpillar shape.” He correctly notes that when the chrysalis form buries itself in the ground, it becomes infected with a fungus. A stem shoots from the neck, which is 8–10 inches high and resembles a club-headed bulrush. It is generally found at the root of the rata tree. He then tells of how the natives eat it and also use it as a pigment for tattooing when burnt and ground to a powder.

Further searching uncovered several letters in a journal called Natural Science News. On July 6, 1895, someone writing to the journal about the aweto stated that “science is not able to say whether it is a vegetable or an animal.” A letter on September 28 of that year sheds some light on the state of science at that time. Someone writing from Clinton, Arkansas, opined that the caterpillar must be dead before the “plant” could live in its body. He went on to say that disease germs are a consequence of rather than a cause of disease. He also mentions similar organisms found in the grubs of May and June beetles in the American south, making the point that it was not limited to New Zealand.

A letter in the December 28, 1895, issue of Natural Science News, reprinted from Scientific American, suggests an answer to the question of why Ripley mentioned the New Zealand aweto when such species are common worldwide. The author notes: “Parasitic fungi are met with in Australia and other countries which attack living and dead larvae, pupae, etc.—upward of 25 recorded species, but none are so conspicuous or so remarkable as Sphaeria robertsii, examples of which may be seen in many museums.”

This letter also uses the term “pepeaweto” suggesting it may have been this article that Ripley’s researcher, Norman Pearlroth, found in the New York Public Library where he had done most of Ripley’s research. It is one word, rather than hyphenated, which would have thrown off my early computer searches. It also contains the Maori word “hotete,” misspelled in the Poe story as “hotte.”

These articles suggest that this sort of fungal parasite first became known in New Zealand and that other related species around the world became known a bit later.

It is just possible that the New Zealand species of Cordyceps has left us a literary legacy. The Ripley and Poe references have come and gone, but it may have inspired Hodgson as well. Poe and Ripley merely described it as some sort of curious plant-animal hybrid. Ripley may not have known much about the nature of the aweto, and Poe merely quoted the American consul to New Zealand in a comical tale. But Hodgson evidently realized its potential in horror fiction.

Hodgson never left to posterity a record of what influenced his fiction, but he did spend eight years at sea in the British Merchant Marine before settling down to be a writer. His years at sea were traumatic in many ways and left a deep imprint on his fiction. One of the ships he is known to have worked aboard was the Euterpe, which sailed a regular route between London and New Zealand. He included these voyages in slide lectures he gave about his nautical experiences. It is possible and perhaps even likely that he came across the aweto during one of these voyages to New Zealand and went on to extrapolate the horrifying implications if such a fungus were to infest human beings. And “The Voice in the Night” has spread its mycelia through succeeding generations of horror fiction.