Parasitoid Wasp, Blue Velvet Worm and Glowworm Caves of Waitomo

 

Long-tailed Ichneumoid Wasp, linocut, 8" x 8" by Ele Willoughby, 2024

Next up for #InsertAnInvert2023 is my hand-printed lino block print on 8" x 8" Japanese washi paper of Megarhyssa macrurus, the long-tailed ichneumoid wasp or ichneumon wasp. It's a parasitoid wasp and its "long-tail" is in fact it's extremely long ovipositor which you can see looping from its back end into the tree. The wasp uses it to deposit an egg into a tunnel in dead wood bored by its host, the larva of a similarly large species of horntail or wood wasp. Its body is up to 51 mm long and the ovipositor on the female wasps can be 130 mm. It can be found in the eastern US and southern Canada around the Great Lakes. 

Blue Velvet Worm, linocut 8" x 8" by Ele Willoughby, 2024

 

July is Subterranean month, which as it turns out, requires some new art. Here's a sneak peek! I stuck fairly close to the first prompt, simply choosing a different velvet worm, than the one suggested, because the colour is so gorgeous. Hence, my Blue Velvet Worm. Velvet worms (phylum: Onychophora) are named for their velvet-like texture and somewhat wormlike appearance. They are elongate, soft-bodied, many-legged nocturnal animals who spit slime to trap prey, somewhere between worms and arthropods. Like an arthropod their heads have segments but otherwise they have wormlike bodies. They have flexible wormlike skin but like insect skeleton in composition. They have insect-like limbs, but they are unjointed and conical in shape. They look like caterpillars who don't become butterflies. The two extant families of velvet worms are Peripatidae and Peripatopsidae. And amongst the latter there are some in the genus Peripatoides which exhibits lecithotrophic ovoviviparity; that is, mothers in this genus produce and retain yolky eggs in their uteri. The eggs are fertilized internally, and babies develop inside their mother until large enough to be born, in batches of 4–6, as colourless miniatures of the parents! Peripatoides novaezealandiae is a species complex of velvet worms in the genus Peripatoides, found throughout New Zealand. This print is made based on photos of P. aurorbis, but all the Peripatoides novaezealandiae have no morphological characters that distinguish them.

 

Glowworm Caves, linocut in regular and glow-in-the-dark ink, 8" x 8" by Ele Willoughby, 2024

Glowworm Caves, linocut in regular and glow-in-the-dark ink, 8" x 8" by Ele Willoughby, 2024, shot in the dark so you can see how it glows.

 

Third week was troglofauna, or invertebrates who live in caves.  I strayed from the suggested species, because I wanted to illustrate invertebrates I travelled to see, in the glowworm caves of Waitomo. My love of bioluminescence overcame my claustrophobia, and I was proud I ventured into caves, even where it was a tight squeeze.

Glowworm cave photo by by Rap, Raft 'n' Rock, Waitomo

That's me, photo
by Rap, Raft 'n' Rock, Waitomo, May 2010

On the North Island of New Zealand or Aotearoa, there are caves near Waitomo with large populations of Arachnocampa luminosa, a glowworm (insect larvae and adult larviform females that glow through bioluminescence) native to the country.

In the limestone caves, these glowworms, a species of fungus gnat endemic to New Zealand, dot the ceilings with glowing light like blue constellations in the night sky. The larval stage and the imago produce a blue-green bioluminescence. They are found in caves and sheltered banks where humidity is high, hence its Māori name "titiwai", meaning "projected over water." They lay eggs on cave walls and the glowing 3 to 5 mm larva emerge, generally in the spring, and select a site to begin producing its silk nest where it will grow to 30 to 40 mm over several months.

The larva spins silk nests on cave ceilings from where they hang up to 30 threads along which it regularly places small sticky droplets to trap prey like other small Diptera (especially midges), spiders and other non-flying invertebrates. Prey is attracted by the bioluminescence and then sticks to the threads. When prey gets stuck, the larva pulls it up by ingesting the snare and starts feeding on the prey alive.

These are a limited edition reduction lino block print. Each is made with glow in the dark ink, so the 8" x 8" prints themselves glow like the glowworms.