Key to Australian Freshwater and Terrestrial Invertebrates

Phylum Arthropoda
Subphylum Myriapoda
Class Diplopoda
Order Julida

Common names: julids

Overview

Most people instantly recognise julids as millipedes because they are so familiar in urban and suburban Australia. They are long, smooth-bodied and cylindrical, and mostly gray or black in colour. They closely resemble spirostreptid millipedes but differ by the presence of legs on the fourth body segment. Some species invade houses where they contaminate food and infest carpets and bedding. Almost all of these domestic julids are introduced species, including the notorious Ommatoiulus moreletii, which sometimes reaches pest proportion in south-eastern Australia. Julid millipedes possess repugnatorial glands, which discharge defensive secretions, including benzoquinones, which are capable of irritating potential predators. Other millipedes (and other arthropods) should always be preserved separately from julidans, as benzoquinones can harden alcohol-preserved specimens and stain them a dark red.

Distribution and diversity

The order Julida has a centre of diversity in the Palaearctic Region. In Australia there are two families, five genera and eight species recorded, all of which are introduced from other areas of the world. They occur over much of the non-arid areas in Australia.

Life cycle

During mating, the males wrap themselves around the female and pass a spermatophore to the female via the modified pair of legs (gonopods) on segment seven. Eggs are laid in the soil or under logs or rocks. Juveniles possess three pairs of legs after hatching. Additional leg pairs and body segments are added through successive moults.

Feeding

Julid millipedes consume decomposing vegetation and vegetable matter, including roots and shoots.

Ecology

Julid millipedes are found under logs and rocks, in leaf litter, and under the bark of trees.

Millipedes can curl up, protecting their soft underside, as a defence mechanism
Image credit: tpgprice
used under a Creative Commons Attribution-NonCommercial license

Portuguese millipede, an invasive species in Australia
Image credit: Nuytsia@Tas
used under a Creative Commons Attribution-NonCommercial license

Blaniulus guttulatus, the 'spotted snake millipede', an invasive species in Australia
Image credit: Tony Daley
used under a Creative Commons Attribution-NonCommercial-ShareAlike license