Centipedes and Millipedes, Pacific Northwest
Harpaphe Haydeniana Millipedes (almond scented millipede) are a common sight in the Pacific Northwest, it stands out with its bright yellow spots running the length of the black body. These spots are a warning to predators that this millipede is poisonous. When threatened, it emits a cyanide gas that smells like almonds but is quite poisonous to other small creatures.
Full grown, it can reach up to 7 cm long. The body is divided into 20 segments, the males have 30 pairs of legs and the females have 31. One of the male’s leg pairs is modified and used to transfer sperm to the female.
The almond-scented millipede can be found in the forests along the pacific northwest coast, from California to Alaska. This millipede lives among the leaf litter and old wood debris on the forest floor, it feeds on dead leaves and decayed wood. It burrows in the forest substrate, turning decomposing plant matter into rich soil. This millipede can venture into the open in the broad light of day, most predators keep a distance from this guy, so this is one millipede that is quite easy to find.
Mating season begins when the male millipede starts to emit pheromones so females can find him. Once a female has found him, he curls his body and transfers the sperm packet from the gonopore on his third body segment to his gonopods on his seventh body segment. The male then gets the female in the mood by massaging her with rhythmic leg movements. Once the female accepts the male, she lifts her front body segments, allowing him access to her genitals where he deposits his sperm in her spermathecae.
The female then builds a nest and deposits hundreds of eggs. The eggs are brown, irregularly shaped and speckled. Newborns have only a few legs and body segments, developing more with each molt. They change from pale gray to black and their spots intensify until they’re fully grown. They live up to three years.