By: Veronica Sommerville
Date: July 25, 2003
You don’t need to be an entomologist to know there is an entire realm living in the shallow dirt and detritus of the land. You only need to be a gardener. The sheer number and diversity of interesting creepy crawlies that are turned up with the flick of a spade can make any self-proclaimed bug lover bust suffer the occasional gross-out shudder.
Ranked particularly high on the gross-out scale are millipedes and centipedes. The number of legs per segment differentiates the two. Millipedes have two pairs of legs per segment while the centipedes must get by with only one pair. With all those legs, millipedes have a carefully choreographed walk that allows them a slow, untangled saunter that resembles the wave.
A commonly sighted millipede in our local forests is Harpaphe haydeniana. This is one anthropod that exemplifies the need for proper nomenclature as it has many common names including cyanide millipede, night train, yellow-spotted millipede and almond scented millipede. I have taken my turn and called it the marzipan millipede and for good reason. When handled the Harpaphe rolls tightly into a ball where only its unpalatable, hard outer casing is exposed and emits a defensive cloud of cyanide, which strangely enough, smells like almonds. This response can be potentially lethal to predators of the insect and rodent world but it delights our sense of smell as it conjures images of Christmas marzipan shaped into small fruits. Don’t be afraid to pick the Harpaphe up, as he prefers to eat dead leaves and wood than a chomp on a finger.
Harpaphe looks menacing enough with its shiny, black distinct segments that are bordered in yellow. Like most brightly coloured animals, this yellow is a hands-off warning to predators that it means business when it comes to survival.
Interestingly enough males and females are distinguishable by their seventh segment. The female has the normal two pair of legs here while the males have only one pseudo pair that actual is a gonopod used for sperm transfer. Their mating produces very small, dark eggs that are laid amoung the forest detritus. Young millipedes are lighter in colour and relatively smaller. As they age, they molt to produce new segments. This takes place in a sealed underground soil chamber where the young Harpaphe will be for several weeks before chewing its way out, renewed and a number of centimeters longer. The millipedes will live to be up to two years old and will molt approximately seven times over their life.
The Harpaphe haydeniana is a beautiful creature that is common in our forests. Next time you are turning over logs or digging through the forest litter and you come across this millipede, pick it up and give it a smell. It will instantly change your opinion of the unknown alien-like world of the many creepy-crawlies that inhabit the earth under our feet.