Wednesday, June 10, 2009

Earwigs



If you grow dahlias or chrysanthemums for exhibiting in flower shows then this little insect, the earwig Forficula auricularia, is probably your mortal enemy. Earwigs like to rest with their flattened bodies concealed in crevices and the space between closely-packed flower petals is perfect. Unfortunately, while they’re there they tend to nibble the petals. But there is a more endearing side to earwig behaviour; unusually for insects, the females show strong maternal instincts towards their eggs and young. They lay their eggs in late summer and guard them through the winter, constantly licking them to keep them free from fungal infection, and then they feed the infant earwigs through those hazardous first days of life. The earwig in the picture is a male, identifiable by those large, curved tail forceps which are used for defence. When they’re threatened, as this one was, they raise their tails like scorpions, forceps at the ready. Females have straighter, more slender forceps and the other purpose of these organs is for gripping one another, during tail-to-tail mating manoeuvres. Earwigs can fly, but rarely do so. Behind the head there are two sets of wings. The front pair is short and rectangular and probably mainly functions to provide rigidity for the much larger, fan-shaped hind wings. Stowing away the large hind wings is a masterpiece of packaging that involves intricate folding, so maybe it’s not surprising that earwigs rarely take flight. You can find some superb videos of earwigs mating, hatching, defending their eggs and moulting at http://www.arkive.org/common-european-earwig/forficula-auricularia/video-09e.html

4 comments:

  1. Good post. I don't see them much these days. When I was growing up in rural Essex they seemed to be everywhere.

    ReplyDelete
  2. Fascinating Phil.
    I knew they could fly, but the rest of the information, especially the maternal instincts, all totally new to me.
    Good post.

    ReplyDelete
  3. Hi Les,They seem to be much easier to find in late summer and autumn, maybe because the young are reaching maturity then. This one was sheltering under a brick.

    ReplyDelete
  4. Thanks Keith. One of the other sligtly unusual things about them - they live for about a year and perhaps up to 18 months.

    ReplyDelete