Care of terrestrial invertebrates
The Australian Museum cares for and displays a wide range of terrestrial invertebrates including scorpions, spiders, insects.
Enclosures vary greatly depending on the type of animal being housed and whether the species is being displayed or not. Arboreal (tree dwelling) insects such as phasmids and large web-building spiders such as Golden Orb Spiders, Nephila plumipes, are provided with tall (60-90cm) terrariums so that they can display natural climbing behaviour. Ground dwelling invertebrates such as Giant Burrowing Cockroaches, Macropanesthia rhinoceros, Egyptian Beetles, Blaps polychresta, and grasshoppers, require less vertical space but require terrariums with relatively large ground surface areas (30-45cm2) as well as sufficient leaf litter, rocks and logs to hide under or behind.Burrowing species including the larvae of many beetles, Sydney Funnel-web Spiders, Atrax robustus, and wolf spiders, Lycosa spp., require suitable substrate to burrow into. This substrate which may consist of peat-moss, potting mix, sand or a combination needs to be kept sufficiently dry or moist depending on the natural habitat where the species is found.
The Museum exhibits attempt to resemble the natural environment of the species being displayed, branches, plants, rocks and leaf litter are used wherever possible to replicate the animals habitat and allow animals to feel comfortable in their homes by hiding behind objects, burrowing or in the case of phasmids and katydids hiding in plain sight.
The Australian Museum has an off display animal room where new animals can be quarantined and acclimated to captivity. More sensitive invertebrates can also be more easily bred in this quieter location and the temperature can be controlled to suit each species need. Many species are also unseen during part of their life-cycles and so are best kept off-exhibit. Beetles for example, begin life as burrowing or boring larvae or grubs which feed off decaying vegetation, either underground or inside wood and so are not suitable for display until they pupate and emerge as adult beetles.
Land invertebrates such as spiders, scorpions and many insects have specific temperature, humidity and lighting requirements that need to be met in captivity. Native slugs and snails and temperate species of spider such as Sydney Funnel-web Spider, Atrax robustus, for example require little light, high humidity and cool conditions. Tropical and arid insects including cockroaches, katydids and grasshoppers require special heating in order to bask and remain active.
Obligate burrowers such as many Australian species of scorpion live in arid environments however these animals burrow to escape high temperatures and utilise the moisture in the soil. These desert species therefore have high humidity and low temperature requirements.
All land-living invertebrates require high or low humidity in order to moult their old exoskeletons and expand their new exoskeletons. An understanding of how the animal successfully moults in the wild is important when providing the right conditions in captivity. At the Australian Museum, species that require low humidity are housed in enclosures which are easily ventilated. Animals requiring high humidity are kept in enclosures with smaller ventilation holes and are mist sprayed daily.
Predatory insects, spiders, scorpions and centipedes are fed live foods such as crickets, wood cockroaches and mealworms (which are not actually worms but the grubs of beetles). Herbivores such as phasmids and grasshoppers are fed freshly cut branches of various plants. This ‘browse’ includes many species of Eucalyptus for the Museum’s phasmids and Abelia for grasshoppers which is grown on Museum grounds. Insects such as Rhinoceros Beetles, Xylotrupes gideon, are fed soft fruits such as mango and banana and many species of Australian cockroach are fed carrot and apple as part of their diet.
Artificial foods are prepared for invertebrates with diets that are difficult to replicate in captivity. One such food is ‘Orthopteran Mix’ which is fed to cockroaches, crickets, katydids, grasshoppers and some beetles. This special mix consists of oats, seeds, pellets, fish flakes, vitamins and minerals. Orthopteran mix is a good diet for omnivorous insects as well as species that have little known about their diet as the varied contents of the mix allow the animals to take the nutrients it requires. The Australian Museum also makes 'Mollusc Mix' which was developed by the Zoological Society of London to raise the endangered Partula Snails of French Polynesia. Mollusc mix is specially formulated to provide protein, vitamins, calcium and other nutrients to snails and slugs which usually feed on fungi and algae in the wild. A selection of fish flakes, pellets, pulpy wood, nectar mix and other foods are used to keep the Museum’s insect collection well fed.
Terrestrial invertebrates need to maintain adequate hydration to remain healthy, however due to the way animals such as spiders and insects breathe (not through the mouth but through pores on the body) they can drown in standing water by simply sitting in it. Therefore water is provided by a soaked piece of cotton wool in a small dish, which the animal can drink from.
Some arboreal spiders such as huntsman’s and insects such as katydids, mantids and phasmids drink droplets from leaves and terrarium surfaces and are sprayed with a fine water misting. Burrowers such as scorpions, trapdoor spiders, funnel-web spiders, centipedes as well as some insects do not drink, but absorb water from the sand or soil. A moisture gradient is therefore provided for these animals by keeping a dry and moist end. The animal can then maintain its hydration needs by burrowing into dry or moist substrate.
Soft-bodied invertebrates such as snails and slugs require moist soil to burrow into as well as moist surfaces to move around and properly feed. Regular spraying provides rainforest-like conditions that prevents the animals from drying out. High moisture can increase the risks of fungal growth which can affect the health of the animals, high ventilation and airflow is used to reduce such outbreaks.
Capture and handling
Harmless insects such as phasmids, cockroaches and katydids can be picked up and transferred to other enclosures by hand. Care is always taken at the Museum to reduce stress on all animals, particularly while being handled for public programs and examinations. Terrestrial invertebrates can be particularly sensitive to handling due to their small size and ability to loose legs, antennae and other body segments.
Dangerous invertebrates such as spiders are never directly handled; they are transported between enclosures and exhibits by a 60mm diameter cup which when placed on its side the spider can be gently coaxed with long forceps into walking into the cup, the cup is then turned back up and lid can be secured.
The Australian Museum does not recommend the handling of spiders or other dangerous animals by unexperienced people without proper training or supervision.
- Henderson, A. Henderson, D. and Sinclair J. 2008. Bugs Alive, A guide to keeping Australian invertebrates. Museum Victoria. Melbourne.
- Matthews, R. W., Flage, L. R. and Matthews, J. R. 1997. Insects as Teaching Tools in Primary and Secondary Education. Annual Review of Entomology, 42, 269-289.
- Newton, M. 2008. A Guide to Keeping Australian Scorpions in Captivity. Mark A. Newton Publishing. Adelaide.
- Sinclair, J. 2008. Keeping Bugs Alive. thylacinus Vol 32 (3), 11-14.
Chris Hosking , Interpretive Officer