Last Thursday I was in the garden shearing the Bay Laurel shrub (Laurus nobilis) as it was getting a bit difficult to pass by, which then meant having to pick up all the bits off the gravel path. I am always creating work for myself. I picked up one twiggy piece and was about to throw it into the bucket when I looked down. Something didn’t feel right. The ‘twig’ felt too soft. I quickly dropped it on the ground and stepped backwards. The ‘twig’ was still on the ground. A pale green in colour, but I thought I could see eyes. Now that didn’t seem right either. I picked it up and popped it onto the baby’s tears (Soleirolia soleirolii) for a closer look. A stick insect? In England? Surely not.
A threatened stick insect will abruptly drop from wherever it’s perched, fall to the ground, and stay very still. This behavior, called thanatosis, can successfully discourage predators.
As I watched it started to move its legs into a bent shape. This was definitely no twig. At this point I hurried indoors to fetch my camera.
There are no native stick insects in the UK, however, three species have become successfully established in Devon, Cornwall and the Isles of Scilly. The stick insects came to be here in the UK, thousands of kilometres from their native lands in New Zealand when plants, including Tree Ferns, from New Zealand were shipped to nurseries in south-west England.
I think mine is the Unarmed Stick Insect (Acanthoxyla inermis). The most common one. This is our longest UK insect with the adult body measuring up to 125mm, although about 100mm is more usual. It has a smooth body with just a few tiny bumps on its back. Colour can be either green or brown, but green is more common. Green ones tend to be a uniform apple green.
After a few photos I carefully picked her up again and placed it back on the Bay Laurel. I checked a bit later on and she had disappeared into the bush. I do hope I didn’t cause her any harm. I am a little worried that I might have removed a leg or two.
The naturalised stick insects seen in the UK are all female and reproduce by laying fertile eggs without the need for a male, a process known as parthenogenesis.