Animal of the Week -- June 23, 2008

It can't possibly have escaped your attention that this week in the UK is National Insect Week -- so naturally I am going to join in the celebrations by nominating an insect as this week's animal. But what to go for? Something gaudy and noticeable, such as the swallowtail butterfly or hummingbird hawk moth, both occasional visitors to these shores? Or maybe our largest insect, the stag beetle, which reaches lengths of up to 7 cm including its antlers? Perhaps a lovely lazy bumble bee, many species of which are in decline all over the UK, or our rarest insect the streaked bombardier beetle, which repels predators by squirting a noxious combination of hydrogen peroxide and hydroquinone that explodes with a noisome smell and a loud pop. Damn it! Perhaps I should do all insects. The most diverse group of organisms on the planet perhaps accounting for 90% of species diversity -- although that might take me some time.

Nah, tell you what, among all the glamorous options, let's celebrate a much maligned species which is one of my favourites, Lepisma saccharina (silverfish). These primitive wingless insects (contrary to some misinformation, not all have wings) have remained largely unchanged for the past 300 million years. I guess they get a bad rep for living among rotting wood and damp places in bathrooms, but really they are just probably eating shampoo residue and other stray starch and cellulose based products such as wallpaper paste, glues, or toast. While they might occasionally start nibbling at the gum holding books together, or in rare times of famine nibble at leather or natural fibres, they're probably not doing much damage to your stuff, they just like damp places... and if your books are damp enough to attract silverfish, you've got damp books anyway.

Most commonly seen fleetingly as they retreat from bright light, nocturnal silverfish glide gracefully with glaucous iridescence, undulating like a minnow across your bathroom floor. I think they are quite beautiful. According to wikipedia, "The reproduction of silverfish is preceded by a "love dance", involving three phases, which may last over half an hour. In the first phase, the male and female stand face to face, their trembling antennae touching, then repeatedly back off and return to this position. In the second phase the male runs away and the female chases him. In the third phase the male and female stand side by side and head-to-tail, with the male vibrating his tail against the female", after which the male deposits a gift of sperm, wrapped in gossamer, which the female picks up. How much of the first bit is true I am not sure, the second bit about the giftwrapped seminal present, however, is true. Although they stop short of a post-coital smoke.

So cut these most ancient but graceful creatures some slack for the remainder of National Insect Week, June 23–29.