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Have you seen...?
Invertebrata 1, Spring 1994

I have been working on the taxonomy of Australian Buprestidae (jewel beetles) for many years and it is now well advanced with a revision of Castiarina - which is the biggest genus with some 430 species. The genus is found throughout Australia and parts of New Guinea.

The few Tasmanian species are interesting because most of them have converged on a common pattern of yellow markings on a green background. They form a typical Mullerian mimicry complex as it has been found that they are protected from predators by having a noxious-tasting organic compound in their bodies.

Three of the Tasmanian species are rare, being known from four, three and two specimens respectively. The rarest is Castiarina insculpta, both known specimens of which were collected from the vicinity of Great Lake. So far, two unsuccessful collecting trips have been made to the highlands. The second specimen was collected in early March at Miena. It isn't known which native flowers the adults feed on, but most likely nectar from the flowers of Leptospermum sp., Eucalyptus sp. or Cassinia flowers which are abundant in the area at the end of summer.

The beetles are about 12.4 mm in length. The head, pronotum, ventral surface and legs are green. The elytra are green with three yellow marks on each side. One notable feature is that the apical spines of the elytra point towards each other. In most other species they are parallel. I would be very interested to identify specimens from this area if they at all resemble this species. A male specimen is urgently needed, so that an illustration of the genitalia, which are used for identification, can be prepared.

Shelley Barker
Department of Zoology
University of Adelaide
Adelaide SA 5005

Acantholybas kirkaldyi Bergroth (Hemiptera: Coreidae) rediscovered
Invertebrata 1, Spring 1994

On the 7th of September, 1993 a single specimen of a small coreid bug that had not been seen since it was originally described in 1909 was collected in an area near Brooks Bay in southern Tasmania. As the original holotype specimen, thought to be held in a European museum, now appears lost the recently found specimen is believed to be the only one of its kind in the world. Little is known of the biology and ecology of this 10.5 mm-long bug which belongs to a tribe of insects (tribe: Colpurini) that has received minimal investigation. Presently, some 15 species are recognised from Australia, 13 of which come from Queensland and five from northern New South Wales. Acantholybas kirkaldyi is the only species known to occur outside these two States. The species was recently placed on the Parks and Wildlife Service's list of insufficiently known native invertebrates. A paper concerning the find will be published shortly. Further specimens, in particular female specimens, are hoped to be located in order to learn more about this interesting species.

Martin Steinbauer
CRC for Temperate Hardwood

Wildlife parasitology
Invertebrata 1, Spring 1994

Wildlife parasitology really needs a kickstart in Tasmania! Heaven knows there are enough interesting prospects out there.

Take the impact of Toxoplasmosis, the cat-transmitted protozoa that kills our Tasmanian marsupials. We know it kills pademelons, Bennett's wallaby, wombats and both species of bandicoot in Tasmania. Domestic and feral cats are the sole carriers with animals in disturbed or isolated habitats most likely to succumb to the infection. By blood-testing indigenous animals in remote areas and on islands for the presence of Toxoplasmosis antibodies we can tell if cats are present. Parks and Wildlife Service is currently looking at the impact of Toxoplasmosis on eastern barred bandicoots in southern Tasmania.

A few interesting beauties which need further workup are indigenous liver fluke infections in Pseudomys higginsi, Rattus lutreolus, Potorous tridactylus and perhaps Antechinus swainsonii and the tapeworm Dasyurotaenia robusta in Tasmanian devils. I suspect that the fluke has a mollusc or annelid intermediate host (like the large land snail, Caryodes). The tapeworm is a real enigma. It was apparently quite common in devils around the turn of the century and then wasn't recorded again until 1987 (at one locality only!) As the parasite is likely to have a two-host predatory-prey life cycle, the chances are its rarity could relate to the scarcity of the intermediate host. The life cycle of the tapeworm is unknown but small mammals or macropods are likely intermediates. Interesting hey!

Chances are there are lots of new species out there. They are part of the ecosystem as much as free-living non-parasitic invertebrates. Research into their lifecycles tells us about their hosts and feeding habits or behavioural associations within a habitat.

David Obendorf
Veterinary Pathologist

Colourful but puzzling
Invertebrata 1, Spring 1994

Argonemertes australiensis (Dendy, 1889) is the common terrestrial nemertine of Tasmania.

It's about 40 mm long when full-grown and resting comfortably. It looks like an overweight flatworm. It can be found all over the State (even in the Midlands) in the usual moist retreats: rotting wood, deep leaf litter and under stones and loose bark.

If you prod Argonemertes, its white proboscis suddenly shoots out from the head end. The proboscis tip then attaches to a firm substrate, retractor muscles are operated and the worm speedily escapes from its enemy (your finger) by pulling itself along the proboscis, which seems to be 'eaten up' as it inverts (or deverts, or something).

Similar behaviour helps Argonemertes capture its prey. It probably eats Collembola and terrestrial crustaceans. These have the advantages of legs, a quicker metabolism and a far more sophisticated nervous system, but the nemertine is faster on the draw.

Argonemertes comes in male and female versions. The eggs are laid in a clear, jelly-like mass about 10 mm long and 3 mm in diameter. I've found egg masses in rotting logs in August and March; the latter were collected and hatched out in May.

There's a small but informative literature on A. australiensis (see references below). The IUCN Red Book says that terrestrial nemertines are 'Vulnerable' but in Tasmania A. australiensis is demonstrably tolerant of habitat disturbances other than clearing for agriculture, plantations or suburbs.

An unresolved question concerns colour varieties. At least three are common around the State: 'Bluehead' (cream with a blue head), 'Mottled' (reddish-tan with irregular red-brown blotches) and 'Striped' (colour as in 'Mottled', but organised into well-defined longitudinal bands). All three can be found in the same locality. I sent specimens of the three from Lookout Hill in the Douglas-Apsley to Dr Janet Moore at Cambridge (UK), who replied that 'they're all exactly the same inside - classical australiensis.' But how do these colour forms persist so 'cleanly' in a presumably interbreeding population?

Bob Mesibov
QVMAG Research Associate

References:

Hickman, V.V. 1963. The occurrence in Tasmania of the land nemertine, Geonemertes australiensis Dendy, with some account of its distribution, habits, variation and development. Papers and Proceedings of the Royal Society of Tasmania 97: 63-77 + plates.

Moore, J. 1975. Land nemertines of Australia. Zoological Journal of the Linnean Society 56: 23-43.

Moore, J. and Gibson, R. 1988. Further studies on the evolution of land and freshwater nemerteans: generic relationships among the paramonostiliferous taxa. Journal of Zoology (London) 216: 1-20.

Winsor, L. The land nemertine Argonemertes australiensis (Dendy) in south eastern Australia. Victorian Naturalist 102: 28-36.

Much worse than 'flu
Invertebrata 1, Spring 1994

A zoonosis is an animal disease which infects humans. Arboviruses are viruses transmitted by arthropod vectors such as biting flies and mosquitoes.

The most widespread zoonotic arbovirus in Australia is Ross River virus, which affects literally hundreds of people annually. The resultant disease is called Epidemic Polyarthritis. Ross River virus is now regarded as the nation's arbovirus of greatest public health importance. Formerly a subtropical infection, the virus has subsequently spread to every Australian State, including Tasmania. Investigations here to date have shown that the widely distributed coastal salt-marsh mosquito, Aedes camptorhynchus, is the principal vector between the marsupial reservoir hosts (mainly macropods) and humans. Ross River virus has also been isolated from pools of the freshwater species, Aedes flavifrons, trapped in the Bicheno area.

Anybody and everybody working or holidaying in coastal regions is at risk. The most likely time for humans to become infected is summer and autumn, and there are cases every year. Local reports of Epidemic Polyarthritis tend to be erratic, depending on rainfall or inundation of coastal lagoons. Due to the disease's relatively long incubation period, 10-14 days, infected people are frequently well distant from the virus source before they become ill. This presents diagnostic difficulties, and leads to considerable under-reporting.

Symptoms are many and various but include a painful joint arthritis, especially of wrists, knuckles, knees and ankles, which can persist for weeks or months. About 10% of sufferers later develop a chronic fatigue syndrome, similar to the after-effects of glandular fever. This can last for up to two years.

There is no specific treatment for Ross River virus disease, apart from analgesics like aspirin to alleviate joint pain. Prevention is the obvious course. Insect repellents containing DEET (diethyl toluamide) must be used on exposed skin surfaces to ward off mosquitoes. Outer clothing should be loose fitting and light-coloured, preferably white. Avoid risky behaviour such as barbeques at dusk adjacent to coastal lagoons and marshland.

Epidemic Polyarthritis is an unpleasant, persistent, debilitating disease. Don't risk catching it. You'll be sorry if you do!

Tim McManus
Veterinary Extension Officer

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