Biomedical Ephemera, or: A Frog for Your Boils

Cicada emerging from its pupal form

Hearing a constant buzzing outdoors this time of year? If it’s not road construction, it’s probably the cicadas. They derive their name from the Latin cicada, meaning “tree cricket”, but their means of sound production - using a “tymbal” on their thorax, rather than the rasping hind legs that crickets use - means that when a number of males get together to call mates, they can reach over 100 decibels. That’s as loud as a low-speed chainsaw, a jet engine at 1000 feet, or a motorcycle you’re riding.

There are large populations of cicadas that emerge only every 13 or 17 years in the United States, but both the US and Europe, there are also sizable populations of annual cicadas that come out every summer, and buzz at us until it’s cold enough to wear sweaters.

Brehms Tierleben, Allgemeine Kunde des Tierreichs. Dr. Otto zur Strassen, 1915.

Atlas Moth (Attacus atlas)

The Atlas moth is the largest moth in the world (measuring over 10 inches across), but that doesn't mean it's long-lived; once it emerges from its cocoon, its sole purpose is to breed - like many butterflies and moths, it doesn't even have a mouth! After about a week outside the cocoon, they die.

De uitlandsche kapellen: voorkomende in de drie waereld-deelen Asia, Africa en America. Pieter Cramer and Caspar Stroll, 1779.

Atlas Moth on Wikimedia Commons

I assume you're talking about Cordyceps? There are many species of Cordyceps, each very specialized to the species that they infect.

Carl Zimmer has a great quick write-up on them on The Loom, and wrote about them extensively in his book Parasite Rex (which is a great book, even outside of cordyceps).

For a quick and graphic explanation of the fungus, Sir David Attenborough had the most well-known Cordyceps genus (that which infects jungle ants) featured back in 2008. The clip is available on YouTube.

Ornithoptera urvilliana (now Ornithoptera primus urvillianus) - D'Urville's Birdwing

Like all birdwing butterflies, the D'Urville's Birdwing is considered endangered, and threatened by their beauty. Serious collectors have caused the extinction of one species of birdwing already, and one other is critically endangered.

While once considered a distinct species, D'Urville's Birdwing can interbreed with other members of Ornithoptera primus, and produce fully fertile and viable hybrids, and as such is now generally considered a subspecies, instead of a distinct species.

Dictionnaire universel d'histoire naturelle. M. Charles D'Orbigny, 1848.

Red Locust (Nomadacris septemfasciata)

The red locust is a sub-Saharan grasshopper in its gregarious phase. Unlike desert locusts, red locusts have not caused any devastating crop destruction since the 1940s. However, the last mass gregarious infestation lasted from 1930-1944 in Chad, the Sahel, and almost all of southern Africa, and was as devastating as the Rocky Mountain locust was in the United States in the 19th century.

Fabre's Book of Insects. Illsutrated by E. J. Detmold, 1921.

Ornithoptera victoriae - Queen Victoria's Birdwing - Adult, Caterpillar, and Egg

This butterfly is a close relative to the largest butterfly in the world, Queen Alexandra's Birdwing. The birdwing genres are noted for their bird-like flight, angular wings, bright colors, and exceptional size.

Like many Lepidoptera (the order containing moths and butterflies), their caterpillars are toxic, owing to the plants they consume, and are not commonly  eaten in their natural habitat. The butterflies retain this toxicity through adulthood.

Proceedings of the General Meetings for Scientific Business of the Zoological Society of London. 1888.

Ammophila urnaria acquiring caterpillar to stock egg burrow

The thread-waisted wasps are all known as "predatory" wasps, and are classified as "parasitoids". Females dig a burrow with several chambers, and collect caterpillars to fill each chamber. They then lay an egg on the top caterpillar, and permanently seal the burrow. This is generally repeated several times, with between 2 and 13 burrows filled with caterpillars.

Thing is...the caterpillars aren't dead. They have to manage to not become dessicated or decayed for the entire period between the laying of the egg and the pupation of the juvenile, a period sometimes longer than several weeks, during the summer. The female wasp stings the caterpillar around the abdomen with a nerve-destroying paralytic poison, and while paralyzed, the caterpillar body automatically utilizes the stored fat (normally used to metamorphose into a moth or butterfly) to stay alive and not rot. Occasionally the caterpillars have been found to die, or not be paralyzed the entire period prior to their becoming food, but the female wasp has an extremely efficacious venom. The caterpillars almost always remain in their chamber until they're eaten alive by the juvenile.

After it pupates, the adult wasp is capable of digging out of the burrow from the inside.

Wasps, Social and Solitary. George Peckham and Elizabeth Peckham, 1905.

Hyperparasitism: Parasites that are parasitic to parasites!

The wonderful world of entomology - parasites within parasitoids all over the place! Though parasites are found throughout the natural world, insects have some of the most interesting examples found between (and sometimes within) the families of the order, including many hyperparasites.

At top, you can see the parasitoid (a parasite that generally consumes or intentionally leads to the death of the host - long-term survival within the host is not the goal) burrowing-wasp parasitizing the rhinoceros beetle larva. Once the female burrowing-wasp "smells" out the location of the larva, she burrows down to it and lays an egg on the body. After her egg hatches, it feeds on the larva. When the beetle larva is consumed, the burrowing-wasp pupates, and forms a chrysalis underground. After metamorphosis, it digs its way up and out, and feeds on pollen or nectar while searching for a mate.

But the insect world does not always let one get away with that sort of parasitoid behavior for free! Many members of the Hymenoptera, including the burrowing-wasps, are in turn parasitized by Strepsiptera, formerly known as the "twisted-winged parasites". This parasitism of parasites (or parasitoids) is known as hyperparasitism, and is mostly found in entomophagous (insect-eating) insects.

As larva, Strepsiptera are free-roaming insects, looking for a host. Once the appropriate host is found, the larvae will enter the insect (using various mechanisms) and take up residence in its abdomen, as can be seen in the image on the bottom-right. Both sexes go through the last instars (moults) of their larval stage within the host. After this stage, there is a vast difference between the females and the males - the males pupate, go through a complete metamorphosis, and emerge from the host as adults (of course, killing the host in the process). The females become neotenous adults (adults capable of reproduction, but with juvenile forms - axolotls are another example), and stay within the host for their entire life. The male mates with them while they're within the host, and their eggs hatch inside their bodies.

Fun fact: When the Strepsiptera larvae emerge from the host, the brood canal they come out of is generally at the top of the abdomen, just below the head, so the host ends up having babies coming out of its "neck". This doesn't kill them, and some hosts end up sustaining three or more broods of its parasite. Cool stuff!

Top: Burrowing-wasp parasitizing rhinoceros beetle. Marvels of Insect Life. Edward Step, 1916. Bottom Right: Adult male Strepsipteran (Stylos dalii), free of host. British Entomology. John Curtis, 1823-1840. Bottom Left: Adult female Strepsipteran and adult female Strepsipteran within host. Applied Entomology. H.T. Fernald, 1921. 

Anonstostoma australiasiae - The Giant King Cricket

A member of the same family as the Giant Wetas of New Zealand, the Giant King Cricket is the heaviest cricket in Australia, and is one of the largest in the world. Living in the rainforest environments of Queensland and New South Wales, these Orthoptera emerge only on wet nights, and eat slow-moving insects and rotting fruit.

King Crickets aren't threatened or endangered, though they're not exactly easy to find. As burrowers, the only real chance for an inexperienced explorer to find one is under significant piles of leaf detritus. But hey! If you're ever stranded in the Queensland/NSW rainforest and come across one, they apparently make as good a meal as the New Zealand wetas! They might not taste great uncooked, but they're not deadly, and aren't especially skittish critters, at the least.

The Naturalist's Library: Introduction to Entomology. James Duncan, Edited by William Jardin, 1840.

A monitor lizard contemplates his meal.

Varanus sp. with Eugaster guyoni, Eremobia cisti, Pamphagus marmoratus.

Hey Paxton, let's play name-the-monitor-lizard! What species is looking at the crunchy Orthoptera?

Brehms Tierleben, Allgemeine Kunde des Tierreichs. Dr. Otto zur Strassen, 1915.