MV Blog

DISPLAYING POSTS TAGGED: invertebrates (7)

The mighty mite part I

Author
by Patrick
Publish date
10 June 2015
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You may not realise it, but tiny mites are ubiquitous—about 50,000 species of mites have been described around the world, with an estimated half a million species yet to be described. They range in size from eriophyid mites at 125 micrometres in length, to velvet mites, the giants of the mite world, at 20mm long.

Red furry mite A Red Velvet Mite (Trombidiidae) from Victoria’s Alpine National Park.
Image: Patrick Honan
Source: Museum Victoria
 

They live in every terrestrial and aquatic habitat in the world, in your house and even on your body. About three quarters of humans have Eyelash Mites (Demodex species) living in their hair follicles and sebaceous pores around the eyelids, eyebrows and nose. Mites also live in the ears of our pets and all over our farm animals. We eat mites regularly, either raw or cooked with our vegetables, in quantities deemed acceptable by food regulators.

Red mite on leaf An erythraeid mite from Rowville, Victoria. These mites are commonly found wandering on eucalypts in bushland around Melbourne.
Image: Patrick Honan
Source: Museum Victoria
 

About 250 species of mites can affect human health, the most pervasive being the House Dust Mite (Dermatophagoides species) which feeds on dander (dead skin flakes). Its poo is the dust we ultimately breathe in. About 10% of people are allergic to this dust, and the average bed may be home to up to 10 million mites. Other mite species are also responsible for scabies and a great range of itches (grain itch, grocer’s itch, copra itch, straw itch, and so on).

But mites aren’t all bad by any means; in fact if it weren’t for them most ecosystems would collapse. They create and maintain soil, and many plant species support ‘mite houses’ (called domatia) on their leaves, providing homes for resident mites that in return keep the leaves clean. While good mites help the plants, the Two-spotted Mite (Tetranychus urticae) attacks and can destroy hundreds of different crops cultivated by humans, and is controlled in glasshouses around the world by the Predatory Mite (Phytoseiulus persimilis).

webbing on plant Two-spotted Mites (Tetranychus urticae) on an indoor plant. The webbing is produced by this species when their populations are high, to protect themselves and their eggs.
Image: Patrick Honan
Source: Museum Victoria
 

The Californian Mite (Paratarsotomus macropalpis) has recently overtaken the Australian Tiger Beetle (Megacephala australis) as the fastest animal on earth, at least in proportion to body size. Humans can run up to 10 bodylengths per second (BLS), the Cheetah up to 20 BLS and the previous record holder, the Tiger Beetle, can move at 171 BLS across the salt flats in north west Victoria. The Californian Mite moves at 322 BLS, the equivalent of a human being running at more than 2,000km per hour.

Mite under a log A trombidiid mite living under a log in wet rainforest at Wilsons Promontory, Victoria.
Image: Patrick Honan
Source: Museum Victoria
 

Mites are also the strongest animals on earth, again in proportion to size. The Tropical Moss Mite (Archegozetes longisetosus), which occurs in Australia and elsewhere, has holding forces in its claws equivalent to 1180 times its own weight, compared to the usual example of ants (50-100 times their own weight) and Rhinoceros Beetles (850 times). That’s the equivalent of an adult human male with a holding force of 90 tonnes.

The life cycles of mites are often quite bizarre. In one group of mites (Adactylidium species), the males die before or just after they are born, and the females are born pregnant and eat their own mothers alive from the inside out. Others live on or in a number of hosts, their body shape and number of legs varying throughout their lives.

Harvestman with red mite A red mite (Leptus species) piggybacking on a Harvestman (Opiliones) in the rainforests of Far North Queensland.
Image: Patrick Honan
Source: Museum Victoria
 

The word ‘mite’ originates from Old English, meaning ‘very small animal’. Mites are remarkably diverse in habitat and life cycle, easily the largest group of arachnids on earth. Although sometimes troublesome, we are dependent upon them in so many different ways, and if they weren’t so small they might take their rightful place in our psyche as some of the world’s most amazing animals. 

MV at sea

Author
by Tim O'Hara
Publish date
4 May 2015
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Dr Tim O'Hara is Senior Curator of Marine Invertebrates.

It is 3am, the night is jet black, the boat heaves with the swell, and a bunch of scientists and crew dressed in full wet-weather gear are silently standing, waiting on the back deck. There is always a sense of excitement as new samples are hauled in. What bizarre deep-sea creatures will be brought up? Perhaps this time we will see the enigmatic mushroom-shaped Dendrogramma, an animal (apparently) that has confounded all efforts at classification since its first collection by Museum Victoria in 1986. Or maybe the massive sea-lice that can devour a dead whale? Or just seafloor life in incredible abundance?

Large blue and white Investigator vessel The Marine National Facility research vessel Investigator at the CSIRO wharf in Hobart.
Image: Tim O'Hara
Source: Museum Victoria

Ship's crew using machinery on deck Deploying the Smith McIntyre grab.
Image: Tim O'Hara
Source: Museum Victoria
 

On Easter Tuesday, four science staff and students from Museum Victoria (Di Bray, Mel Mackenzie and Skip Woolley and I) joined scientists around Australia on a trial voyage of Australia’s brand new research vessel, the Investigator. The idea was to test out all the gear necessary for deep-sea exploration, from iron box-like dredges, used for over 200 years to collect samples, to the high tech cameras that bounce above the seabed, worked in real time from a joystick and a bank of computer monitors in the bowels of the ship, thousands of metres above. We went south of Hobart into the Southern Ocean, specifically to look at life on underwater sea mountains in the Huon one of the Commonwealth’s recently declared marine reserves.

People in the Investigator vessel lab The sorting lab: Skip, Di and Mel facing Karen Gowlett-Holmes of CSIRO.
Image: Tim O'Hara
Source: Museum Victoria

Big camera rig on ship deck The towed deep-sea camera.
Image: Tim O'Hara
Source: Museum Victoria
 

But I had another motive to joining this trip. Next year in November I will be chief scientist of a voyage from Brisbane to Hobart that will survey Australia’s abyssal sea-plain (4000 m below sea-level). So I really wanted to learn all I could about the capabilities of the vessel and think about best practice scientific procedures to ensure we get the most out of the expedition.

The Investigator, run by the Marine National Facility funded by the Commonwealth Government, is a large (94 m), elegant and efficient platform from which to do deep-sea research. Diesel electric engines keep the noise down and high tech stabilisers prevent much of the pitch, yaw and roll that can make life miserable on smaller boats.

People on ship deck The crew deploying gear off the stern deck.
Image: Tim O'Hara
Source: Museum Victoria

Ship crew deploying gear Preparing for the next catch: MV staff in canary yellow facing Mark Lewis of from CSIRO with Mark McGrouther of the Australian Museum looking on.
Image: Tim O'Hara
Source: Museum Victoria
 

My main memories of the trip: dark thundery night skies, albatrosses, friendly company and lots of carbs to eat. All too soon we steamed back to another sunny day in Hobart. We didn’t find Dendrogramma – maybe next time.

Invertebrate Keeper Workshop

Author
by Kate C
Publish date
12 August 2014
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Children are sponges: if kids see and hear that invertebrates are fascinating, wonderful and complex, they are eager to appreciate them. Likewise, the next generation of spider-squashers is created when children are told only that bugs and spiders are disgusting, dangerous or scary. Naturally, when you get a roomful of invertebrate keepers from zoos and fauna parks in a room, they’ll discuss how best to show kids that invertebrates are magnificent.

Invertebrate Keeper Training Workshop Invertebrate Keeper Training Workshop participants ponder the big issues with Maik from Live Exhibits: how do you know if your millipede is male or female?
Image: Patrick Honan
Source: Museum Victoria
 

And so it was at the Invertebrate Keeper Training Workshop at Melbourne Museum last week. Presented by the Australasian Society of Zoo Keeping (ASZK) and run by Jessie, Chloe and Patrick from MV Live Exhibits, the workshop covered all kinds of techniques for keeping, breeding and displaying living invertebrates, and their educational value. When I dropped in, they were poised to begin a snail race—a contest of extreme athleticism where snails compete to reach the edge of a circular arena.

Snail race And they're off! Snails racing.
Image: Patrick Honan
Source: Museum Victoria
 

The purpose of the race was to show ways to get kids thinking about the biology of minibeasts. Jessie from Live Exhibits explained that in the time it took for the snails to slide over the finish line, you can discuss why they prefer to crawl over damp surfaces, why they don’t like being blown upon, and other quirks of snail life. Jessie also described an excellent way to overcome insect fear in small children while holding large invertebrates like stick insects. “Ask them, can you see its eyes? Can you see the claws on its feet? And they come closer and closer without realising it.”

The workshop also covered how to house, feed and breed invertebrates; how to collect them legally and ethically, and how to keep populations healthy. Participants also got a tour of the Live Exhibits back of house facilities where the museum’s invertebrate colonies are kept, our Entomology collections, and a trip to Melbourne Zoo to see their Butterfly House. Invertebrate keepers talk about stuff you don’t hear every day, like how to breed whip scorpions (it’s tricky but not impossible), and what type of heating to use create a humid insect room (hydronic is best).

And the winner of the snail race? This tearaway Garden Snail streaked across the line not once, but twice, before most of the others had even left the centre ring. The Phar Lap of the snail world. 

winning snail The winner of the snail race glides over the finish line.
Source: Museum Victoria
 

John Abbot’s Lepidoptera

Author
by Hayley
Publish date
8 March 2013
Comments
Comments (1)

The MV Library holds an important collection of 18th and 19th century scientific literature. Many of these books began as working tools for early museum curators studying the local fauna. Now, they form part of our rare book collection and are prized for their beauty and rarity.

The library's collection has an interesting history, forming from the amalgamation of two specialist collections from the National Museum of Victoria and Science Museum. Books have been purchased since the earliest days of the National Museum of Victoria, when the first director, Frederick McCoy, acquired important titles such as the entomological works of Maria Sybilla Merian.

While the library collection at MV is relatively small, it is also surprisingly unique. Library staff are currently working to identify titles unique to Australian libraries, a project which has exposed some real gems in the collection, such as John Abbot’s The Natural History of the Rarer Lepidopterous Insects of Georgia (1797).

Tab V, ‘American Brimstone Butterfly’ Tab V, ‘American Brimstone Butterfly’ via the Biodiversity Heritage Library

Abbot left his native England in 1773 for the colony of Virginia in North America, in order to procure specimens and make drawings of the local insects. Following the outbreak of the American Revolutionary War in 1775, Abbot moved to Georgia, where he spent the rest of his life recording the local insects and birds.

Tab XLIX, ‘Corn Emperor Moth’ Tab XLIX, ‘Corn Emperor Moth’ via the Biodiversity Heritage Library

Although he was a prolific natural history artist and well regarded in his lifetime, Abbot is not as well remembered as some of his contemporaries, who included famous naturalists such as John James Audubon. While he is thought to have created four to five thousand watercolours, most of them were unpublished or uncredited during his lifetime.

The Natural History of the Rarer Lepidopterous Insects of Georgia includes 104 hand-coloured plates by John Harris, after original artwork by John Abbot. It's an important early work to depict North American butterflies and moths, and has been appreciated by scientists and collectors alike for its accuracy as well as its beauty. The introduction was written by James Edward Smith, a founder of The Linnean Society of London.

While it is exciting to encounter rare material in our collection, it is also nice to be able to share it. Luckily, the work has been digitised and is now freely accessible through the Biodiversity Heritage Library, so have a browse online or download your own copy of this rare work!

References

Gilbert, P. & Hamilton, C., Entomology: A Guide to Information Sources, London & New York: Mansell, 1990.

Gilbert, P., John Abbot: Birds, Butterflies and Other Wonders, London: Merrell Holberton and Natural History Museum, 1998.

Job, Frank, “The Library of Museum Victoria” in Rasmussen, C. (ed.), A Museum for the People: A History of Museum Victoria and its Predecessors, 1854-2000, Carlton North, Vic.: Scribe Publications, 2001.

Rogers-Price, Vivian & Griffin, William W., "John Abbot: Pioneer-Naturalist of Georgia," Magazine Antiques (October 1983): 768-75.

Faces of the north

Author
by Patrick
Publish date
9 March 2012
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Live Exhibits staff visited Cairns and Cape Tribulation in North Queensland in December to augment our live animal collection with fresh genetic stock. We met many interesting animals along the way, so here are a few portraits of the critters that came back with us to Melbourne Museum.

The Giant Mantid is one of the largest mantid species in Australia. They feed on a range of insects but are large enough to overpower small frogs and lizards. Giant Mantids are currently on display in Bugs Alive!.

giant mantid Giant Mantid, Heirodula majuscula.
Image: Patrick Honan
Source: Museum Victoria
 

Raspy crickets derive their common name from the fact that all known species, both male and female, can produce a rasping sound at all stages of development. There are more than 200 species of raspy crickets in Australia and new species are regularly discovered. This very large adult female has powerful jaws and, like all raspy crickets, a bad temper. She ate her way out of several containers on the journey from North Queensland, causing havoc wherever she went.

Raspy Cricket Raspy Cricket, Chauliogryllacris species.
Image: Patrick Honan
Source: Museum Victoria

A male Golden Huntsman, probably the largest huntsman in Australia and generally considered the second largest in the world. This species sometimes causes panic when it enters houses, but like most huntsmans it is relatively harmless.

Golden Huntsman spider Golden Huntsman, Beregama aurea.
Image: Patrick Honan
Source: Museum Victoria

Net-casting Spiders are famous for their ability to spin perfectly rectangular silken nets, about the size of a postage stamp. These nets are thrown over passing prey as the spider sits suspended above an insect pathway. In honour of their enormous eyes, they are also known as Ogre-Faced Spiders.

Net-casting Spider Net-casting Spider, Deinopis bicornis.
Image: Patrick Honan
Source: Museum Victoria
 

French's Longicorn is one of Australia's larger beetle species. This one was found in a small mating aggregation on a strangler fig in the rainforest at night. Longicorns are characterised by kidney-shaped eyes which wrap around the base of the antennae.

French's Longicorn beetle French's Longicorn, Batocera frenchi.
Image: Patrick Honan
Source: Museum Victoria
 

The spiny legs of the Serrated Bush Katydid give it both its common and scientific name. Adults are always green, but nymphs may be red, brown or violet, depending on the colour of the leaves on which they feed. Males produce a short, loud call which is commonly heard in the rainforest at night. Another katydid, the Kuranda Spotted Katydid, is one of the larger and more robust of this group in Australia. The nymphs closely resemble ants, which may afford them some protection against predators. The eggs are glued to dead twigs by the female using a short, thick ovipositor.

katydids Left: Serrated Bush Katydid, Paracaedicia serrata. | Right: Kuranda Spotted Katydid, Ephippitytha kuranda.
Image: Patrick Honan
Source: Museum Victoria
 

These creatures, and many more, can be seen every day in Bugs Alive! at Melbourne Museum.

A moth flurry on the Murray

Author
by Mark Norman
Publish date
15 December 2011
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Mark is Head of Sciences at Museum Victoria. He's reporting back from Neds Corner in this series of blog posts.

There was a flurry of excitement among our moth team over the diversity of moths and some exciting new records for the region and state. Members of the Entomological Society of Victoria, Marilyn and Dean Hewish, Grace Lewis, Ken Harris and Josh Grub, set up night light stations with bright mercury vapour lamps in front a large white sheet. They run all night, as different groups of moths arrive at different times of the night. They clocked up over 120 moth species.

Two Neds Corner moths Left:Sceliodes cordalis | Right: A perfectly camouflagued Convolvulus Hawk Moth, Agrius convolvuli.
Image: M. Hewish
Source: M. Hewish
 

There are several theories on why moths come to human light sources. The generally accepted theory is that moths use points of light in the night sky (such as the moon) to orient their flight paths. They keep the brightest light at a particular angle to their flight direction in order to fly straight. As they go past our electric lights they keep turning inwards to maintain the correct angle until they spiral into the porch light or the light station sheets.

The arriving moths came in all shapes and sizes. Two of the weirdest were the Twisted Moth and the plume moths. The Twisted Moth contorts its body as part of its camouflage to look very not-moth-like. The plume moths have long narrow wings with the rear pair hidden under the front pair. They get their name from the feathery tips to their wings.

Two Neds Corner moths Above: Twisted Moth, Circopetes obtusata looks just like a dry eucalyptus leaf. | Below: A plume moth, Stenoptilia zophodactylus
Image: M. Hewish
Source: M. Hewish
 

Colour patterns ranged from the excellent camouflage of the hawk moths that perfectly match the grey tree bark to brightly coloured forms including some with false eye spots, known as ocelli.

Two brightly-coloured Neds Corner moths Two brightly-coloured Neds Corner moths. Left: Pale Spotted Tiger Moth, Amata aperta | Right: Grammodes ocellata with beautiful eye-spots, or ocelli.
Image: M. Hewish | D. Hewish
Source: M. Hewish | D. Hewish
 

The wood moths (family Cossidae) caused the most excitement. These beautiful moths are not particularly common and the three species found included two ornately-patterned species and a third smaller species that is a new record for Victoria. The males of these moths (and many other moth groups) can be recognised by their large feather-like antennae. These are the chemosensory organs of the males, used to 'smell' the pheromones released by the females. By contrast, females have much narrower, less-feathery antennae.

two wood moths Two wood moths. Left: Endoxyla sp. | Right: Endoxyla neuroxantha representing a new Victorian record for this species.
Image: M.Hewish
Source: M. Hewish
 

Bush Blitz is a biodiversity partnership discovery program between the Australian Government, BHP Billiton and Earthwatch Australia, that aims to document the plants and animals across Australia's National Reserve System. Museum Victoria also participated in Bush Blitz at Lake Condah in March 2011.

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Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

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