Some of the most unusual endemic insects in New Zealand are the wētā, orthopterans. They’re often referred to as “crickets,” but they’re in the families Anostostomatidae and Rhaphidophoridae and not the cricket family (Gryllidae). Although Wikipedia says that there are 70 species of wētā (all endemic to this country), there are doubtlessly a lot more, as another guide I have lists several unnamed species.
Besides all New Zealand species of wētā being flightless, they are famed for their fierceness and size. The world’s heaviest insect is the Little Barrier Island Giant Weta (Deinacrida heteracantha), weighing in at a ponderous 9-35 grams (0.3-1.3 oz), but can weigh as much as 70 grams (2.5 ounces), which means that only about 6 of the biggies would weigh a pound. Here are two pictures of that species (not my photos):
These now live on the island as they were destroyed by introduced mammalian predators. The early Maori also liked to eat them. (See here for additional facts.)
Another strange species is the Mountain Stone Wētā (Hemideina maori). A denizen of high altitudes on the South Island, it can survive being frozen solid for months. Wikipedia says this (see also here and here):
Mountain stone weta can survive being frozen for months in a state of suspended animation down to temperatures of about -10 °C. At temperatures below -10 °C approximately 85% of their body water is crystallised, which is one of the highest ice contents known for any animal. During winter their haemolymph (the insect equivalent of blood) contains low molecular weight cryoprotectants such as amino acids especially proline (up to about 100 mM) and the disaccharide trehalose. These substances are synthesized during autumn and their concentration decreases again during spring and summer (Proline concentration decreases to about 10 mM during summer). The amino acids and sugars presumably help to decrease the ice content colligatively. However, they probably also have a direct protective effect on membranes and proteins via direct interaction or by modifying the water layer with the closest proximity to the molecules. It also displays the defensive behaviour of “playing dead”, by lying still for a short time on its back with legs splayed and claws exposed and jaws wide open ready to scratch and bite, this behavior is often accompanied with regurgitation.
Here’s a Mountain Stone Wētā (not my photo):
Finally, Tree Wētā of several species (genus Hemideina) are common, and they’re fearsome, as males have huge heads and can inflict a nasty bite (they’re found in dead wood, and can live in firewood piles around houses). This video shows a cat encountering what I think is a tree wētā. Look at that head and those pincers! The sexual dimorphism probably indicates that the males fight each other for females.
Two days ago Geoffrey, my host, took me on a hike above Lake Okatina to look for cave wētā. There are several species, all of course living in caves, and all with huge antennae and long, spindly legs. The species we were looking for is almost certainly the Oparara Cave Wētā (Gymnoplecton spp.) Geoffrey had spotted them before in these shallow caves that the Maori dug in hillsides that, when first used, were on nearly vertical slopes that have now eroded into hills.
It’s not clear why the Maori dug these caves: it could be to store the bones of their ancestors, their food, or even to hide out (they can hold one or two people). What is clear is that they’re inhabited by hordes of cave wētā, which can bite. When you crawl into one of these caves with a flashlight, you have to make sure you don’t brush the opening or the top, or you could get bitten. It’s a bit anxiety-inducing!
Once inside, when you shine the flashlight on the ceiling, you find it covered with cave wētā, which, with their long legs and longer antennae, look like spiders. I’m not generally a timid person, but I was fearful they’d all come raining down on me!
These photos were taken by using a flashlight to focus the camera, and then, turning off the flashlight, shooting blindly at the ceiling. I think they turned out well, all things considering:
I inverted this photo so you could see its features. They normally hang upside down on the ceiling. Note the reduced eyes, common in cave animals.
Because the Maori complained that Europeans raided caves to steal the treasures interred with their ancestors, the New Zealand government built this concrete bunker atop the hill to house the remains, complete with a lockable steel door. But of course that got broken into as well, and now Maori bury their dead in special cemeteries. Geoffrey said that there were rumors that this bunker, once emptied, was inhabited by a European hermit for two decades. It’s a horrible place to live as it’s cold, dank, and dark, and I’m not sure that story is true!
h/t: Nicole Reggia