Key to Australian Freshwater and Terrestrial Invertebrates

Phylum Arthropoda
Subphylum Hexapoda
Class and Order Diplura

Common name: diplurans

Overview

Diplura are elongate, wingless, usually colourless hexapods. They have long, slender antennae and no eyes. In contrast to other hexapods, they also have two cerci at the tip of the abdomen. These can be either long, with many segments, or heavily sclerotised pincer-like and used for grasping prey. Some diplurans, especially larger species, are sometimes mistaken for earwigs (Dermaptera) due to their darkened and pincer-like cerci. Most diplurans are very small and usually less than 5 mm in length, however some species may be up to 50 mm.

Distribution and diversity

Diplura occur worldwide. Around 800 species are known. In Australia they are widespread, but more common in the wetter forest regions; they are also known from the arid parts of the continent. Twenty-eight species in 10 genera and five families are recorded for Australia, with predictions that the total number will increase with further collecting.

Life cycle

Sperm transfer is indirect and similar to that of Collembola, the male depositing on the substrate a spermatophore (sperm packet) that is taken by the female. Clusters of eggs are laid in decomposing plant material or in crevices in the soil. In some species, the females are known to guard the eggs and recently emerged larvae. The larvae resemble small adults. Moulting continues throughout life and an adult can moult up to 30 times during its lifetime, which may be up to a year in duration.

Feeding

Diplurans have chewing mouthparts and some are herbivorous, others predaceous. Herbivorous species feed on plant roots and on fungi that are decomposing plant matter. Predatory species wait buried in soil with the tip of their abdomen on the surface, and capture small soil arthropods that come in contact with their pincer-like cerci.

Ecology

Diplurans mainly occupy moist environments, and are often found in small groups or colonies in soil, leaf litter, moss and under rocks, logs or the bark of trees. A few species have also been found in the nests of ants and termites, and in caves. Elsewhere in the world some root-feeding species have been reported as pests of crops such as sugar cane, peanuts and melons.