Highlands Giant Acrophylla stick insect (Acrophylla alta) Photo By Ross coupland – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=171201338

Goodness, Readers, clearly Bug Woman needs to head to Australia to check out the invertebrates, because this chunky stick insect is thought to be the heaviest insect in the country, weighing in at 44 grams, about as much as a golf ball. It can grow to about 40 cms long, and even has wings, though it’s thought that these are probably used to help the insect glide downwards rather than do anything more spectacular. Which is probably just as well, as being clunked on the head by a massive stick insect is probably one of the more colourful ways to get concussion.

You may wonder how such a huge insect has evaded scientists until this year, but the Highlands Giant Acrophylla is extremely well camouflaged, as you can see, and also lives in the Wet Rainforests of Queensland, described by New Scientist as ‘a true wilderness’ (and long may it remain so). Also, the insect is a canopy dweller, hanging around up to 60 metres above the ground, and it also lives only at altitudes above 900 metres. Scientists currently have no way of knowing how rare or common the insect is, because it’s so hard to survey the region.

This stick insect does remind me of one that I found in Cameroon though…I still have no idea of the species, but the finding of the Australian stick insect has made me want to find out more about this creature. iNaturalist has a stick insect group, so maybe I’ll wander over there….

Startling as they are, it’s worth remembering that stick insects are all harmless plant eaters, just trying to pass themselves off as leaves or sticks in the hope of being left alone. And furthermore (she says in a whisper) there are three wild stick insect species in the UK, in frost-free parts of Cornwall, Devon and Dorset. All of them are species from New Zealand, and are thought to have arrived as eggs in imported tree ferns – stick insects simply drop their eggs rather than laying them with any thought or consideration, slatterns that they are, and the eggs hid away in the crevices of the plants until they hatched and tiny stick insects emerged.

Once here, they set about making themselves at home and, as females are parthenogenic (can lay fertile eggs without needing a male) the populations have increased to a reasonable size, though there is no indication that they have caused any problems to plants. It was thought that all the insects in the UK were female, but then a lone male was discovered in 2018. Some of these populations have been here a very long time: the Prickly Stick Insect was discovered in Tresco Abbey Gardens in Cornwall in 1909, and the Smooth Stick insect in 1949, while the final arrival, the Unarmed Stick Insect (a name which begs a number of questions) was first seen, in Truro, in 1979. So it appears that Cornwall is the stick insect capital of the UK. Whether the insects will wander further as the climate warms is anybody’s guess.

Personally, I’m awaiting the arrival of the Praying Mantis, and possibly the Ant Lion. It’s only a matter of time….

Unarmed Stick Insect (Acanthoxyla inermis) Photo by By jacog – https://www.inaturalist.org/photos/35254511, CC0, https://commons.wikimedia.org/w/index.php?curid=78595029