in my garden | an alien invader

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. 

Source of information is from the Bug Life website and also the Phasmid Study Group

52 Comments

  1. Ali says:

    That’s amazing! A childhood friend had a pet stick insect. She used to feed him privet.

    1. Heyjude says:

      Yes. The one we looked after during the school holidays only ate privet. I had to send my kids around the neighbourhood stealing it from other gardens. Maybe the bay is like privet.

  2. What an amazing find. I didn’t know they lived in this country at all. Lovely (?) photos of it

    1. Heyjude says:

      I am just so glad I didn’t chop her up!

  3. Jim Stephens says:

    Thank goodness not every introduced alien species is a voracious pest. We can look on it as an interesting addition to our fauna.

    1. Heyjude says:

      A shame they don’t eat slugs…

  4. restlessjo says:

    I would have jumped very high, and then possibly landed on the poor crittur 😦 😦 I do sometimes feel grateful that I don’t live in Australia though. 30cm!!!

    1. Heyjude says:

      They breed them BIG over there! And in SA. One thing I didn’t like about living there was the size of the bugs ‘n’ beasties.

  5. Su Leslie says:

    What a cool find. I didn’t know we’d sent you some of our stick insects; only fair I guess, considering how much British flora and fauna now resides in NZ. Do these non-Mati g females produce only female off-spring I wonder? That must be limiting for the gene pool.

    1. Heyjude says:

      They have managed to fertilise their eggs without males. Men had better watch out!

      1. Su Leslie says:

        I think it’s a kind of cloning. They do only produce females. What a thought!!!! Never again finding the toilet seat left up. 🙂

        1. Heyjude says:

          Now there’s a thought.

  6. bushboy says:

    Wonderful. Glad you took great care of the stick insect

    1. Heyjude says:

      I hope she recovered from the shock!

      1. bushboy says:

        I am sure she would have

  7. I love stick insects and was excited and surprised to find photos on your blog, had no idea they’d got into the UK! Liz from New Zealand.

    1. Heyjude says:

      No more surprised than me!

  8. What a splendid post. What a find. What sharp photos. And what good information

    1. Heyjude says:

      I was so surprised to find one in the UK I had to look it up and then discovered the Phasmid study group which is where I got the information from. Exciting to think she might not be on her own in the garden.

  9. pommepal says:

    That’s interesting Jude, I wonder if all stick insects reproduce without males. Makes me wonder if there are any males around. I love our stick insects, love the way they walk.

    1. Heyjude says:

      I think it is just this particular species.

  10. Joanne Sisco says:

    I’m smiling wryly to myself. In contrast to your excitement about this unusual find in your garden, I admit freely my reaction would have been considerably less dignified 😏

    1. Heyjude says:

      I did drop her rather quickly Jo! And then when I realised what it was I wasn’t so scared.

      1. Joanne Sisco says:

        It’s funny, but shortly after I read your post, I discovered a very large bright green bug with way too many legs on the ceiling in my kitchen. I’ve never seen anything like it before … and it quickly got vacuumed up.
        Bugs beware … my house is a zero tolerance zone.

        1. Heyjude says:

          I’ll remember to tell my bugs to stay well away from your house 😀

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