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DISPLAYING POSTS TAGGED: bug of the month (19)

Renaissance for rare plant

Author
by Andrew
Publish date
1 December 2011
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Exhibition horticulturalist Andrew Kuhlman is turning December's Bug of the Month into Plant of the Month. He is one of the Live Exhibits staff that tend the plants in the Forest Gallery and Milarri Garden.

The story of the Shiny Nematolepis, Nematolepis wilsonii, is about a humble plant experiencing a resurrection following the Black Saturday bushfires. The Shiny Nematolepis, a white-flowering shrub also affectionately known as 'Shiny Nem', is considered critically endangered.

There was a single population of 11 mature wild plants before February 2009 according to the Department of Sustainability and Environment. Since the 2009 bushfires over 200,000 seedlings have emerged in the Yarra Ranges. This means practically the entire known population of this plant existing in the wild can be traced back to a single event.

Nematolepis wilsonii plant A plant from the original population that was burnt out in the 2009 Black Saturday Bushfires.
Image: John Broomfield
Source: Museum Victoria
 

The other side to this story is about the cultivated populations of this species, one of which is growing in the Forest Gallery exhibition at Melbourne Museum. These plants are now some of the oldest of the species known to exist. They were grown in 2000 from cutting material sourced from the original population that was burnt out.

Man planting a plant Museum Victoria Exhibition Horticulturalist Brendan Fleming planting a cutting grown Shiny Nematolepis into the Forest Gallery exhibition.
Image: Andrew Kuhlmann
Source: Museum Victoria
 

The display of 'Shiny Nem' plants in the Forest Gallery exhibit is a great chance to get close to a very rare plant in a setting representing its natural habitat. It's also an opportunity to reflect on how close this plant was to disappearing forever and the benefits that having a second chance will bring.

Links:

National recovery plan for the Shiny Nematolepis (Nematolepis wilsonii)

Forest Gallery helps secure incinerated plant's future (2009)

Bug of the month

Author
by Maik Fiedel
Publish date
1 November 2011
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Maik is an Assistant Keeper with the Live Exhibits Unit.

Live Exhibits recently acquired some Flinders Ranges Scorpions. They are not on display to the public but will be used for educational purposes.

The Flinders Ranges Scorpion (Urodacus elongatus) is one of Australia's largest scorpion species, with males growing up to 120mm long. Females are usually shorter and more full-bodied. The adults of both sexes are uniformly brown in colour.

These scorpions are found throughout the Flinders Ranges of South Australia. Sexual dimorphism is obvious in this species with males having a very elongated tail, which is where the species name elongatus comes from.

Male and female Flinders Ranges Scorpions. Sexual dimorphism within the Flinders Ranges Scorpion Urodacus elongatus. Male on the right with elongated tail.
Image: Maik Fiedel
Source: Maik Fiedel

Being a temperate species, it can be found living under rocks and logs in the moist gully areas of the ranges. They are territorial and usually solitary. These scorpions build a scrape under rock, creating a shallow burrow. In order to maintain a stable microclimate, they seal off their burrows as temperatures rise.

Scorpions are negatively phototaxic (moving away from light) and they hunt for their prey at night. It is possible for scorpions to overpower prey that is larger than themselves, such as skinks or centipedes, however, they prefer food items roughly 50 per cent of their own body size. Females will also eat their own offspring if stressed or starved. Scorpions drink water droplets off rock surfaces and also obtain water via osmosis. During the cooler months of the year, the scorpions are less active and will generally feed less.

scorpion eating a cricket Urodacus elongatus feeding on a cricket.
Image: Maik Fiedel
Source: Maik Fiedel
 

As part of courtship, an interesting 'mating dance' is performed. The male takes hold of the female and stings her claw, which has a calming effect. This is necessary because if she becomes aggressive she will attempt to kill the male. In order to mate successfully the scorpions need to be positioned on an even rock surface. The male looks for the correct surface, without breaking his hold of the female. When it is found he deposits his spermatophore onto the rock surface and he drags the female over the top for fertilisation. Once the female has received the sperm the male releases his hold and departs.

A pair of Flinders Ranges Scorpions A pair of Flinders Ranges Scorpions prior to engaging in the mating ritual, which includes the mating dance and the sexual sting.
Image: Maik Fiedel
Source: Maik Fiedel

After about 18 months, the female gives birth to 20-50 live young which climb up onto the her back. They leave her back at two months of age, to go their own way. Flinders Ranges Scorpions reach maturity (adulthood) after four years and can easily live up to eight years.

Australia's scorpions are not considered dangerous to humans, however, scorpions are venomous. There is still a possibility that you may be allergic to their venom, like some people are allergic to a bee sting. You should never touch a scorpion with your bare hands.

Scorpion glowing under UV light. Like all scorpions, Urodacus elongatus will fluoresce under UV light.
Image: Maik Fiedel
Source: Maik Fiedel
 

Further reading:

Newton M.A. 2008. A Guide to Keeping Australian Scorpions in Captivity, Mark A. Newton Publishing

Links:

Infosheet: Scorpions

Infosheet: Scorpion facts and fallacies

Bug of the month

Author
by Melvin
Publish date
1 October 2011
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This post is by Melvin Patinathan, Assistant Keeper with the Live Exhibits Unit.

The Giant Burrowing Cockroach (Macropanesthia rhinoceros), also known as the Rhinoceros Cockroach, is one of Australia's treasures. It is the world's heaviest cockroach, weighing up to a whopping 30g. Although it is not the longest, it still can get up to 70-80mm in length (the longest is probably the winged Giant Brazilian Cockroach, Blaberus giganteus, growing up to 90mm). This giant critter is wingless and heavily armoured, which helps it withstand predator attacks – if that doesn't work it can emit a hissing noise which can be quite startling.

Giant Burrowing Cockroach Giant Burrowing Cockroach (Macropanesthia rhinoceros).
Image: Alan Henderson
Source: Museum Victoria

I recently took the specimen below to Scienceworks for the Inspiring Scientists weekend, where he was a giant hit with hundreds of young visitors. Although I'm fond of many of the animals we keep at Live Exhibits, Giant Burrowing Cockroaches are one of my favourites.

Giant Burrowing Cockroach in hand The handsome hand shows how big a male Giant Burrowing Cockroach can get.
Image: Adam Elliot
Source: Museum Victoria
 

Giant Burrowing Cockroaches are found in dry eucalyptus scrubland of northern Queensland; Cape York to Rockhampton and the Whitsunday Islands. Male cockroaches have a prominent ridge on their pronotum (an extended first segment of the thorax of the insect that forms a shield over its head) where females do not have a distinct ridge but tend to be larger and heavier than males.

sub-adult Giant Burrowing Cockroaches A few sub-adults collecting dry eucalyptus leaves on the soil surface.
Image: Patrick Honan
Source: Museum Victoria
 

Like their name suggests, they are burrowing creatures and use their shovel-like pronotum and large spiny powerful digging legs to dig burrows as deep as one metre. The cockroaches line their burrows with twigs and dry eucalypt leaves that they gather from the surface. These gentle giants are specialist feeders; they only eat dry, crisp eucalypt leaves.

Giant Burrowing Cockroach emerging from its burrow in a terrarium Giant Burrowing Cockroach emerging from its burrow in a terrarium.
Image: Rodney Start
Source: Museum Victoria
 

Giant Burrowing Cockroaches are nocturnal and spend most of their time hidden in their burrows. They are most active at night when they come to the surface to feed; these giant cockroaches have been mistaken for small turtles when crossing roads.

Giant Burrowing Cockroaches generally do not venture too far away from their burrows except during breeding season when it is warm and humid, especially after rain. The warm humid climate provides ideal mating conditions and mating occurs at night. Once the female is gravid (pregnant) she will prepare her burrow by dragging down leaves to feed her young. This species of burrowing cockroach are oviviparous, which means that the eggs are incubated within the body and are sustained by yolk sacs.

young Giant Burrowing Cockroaches and adult female Juveniles and their mother at the entrance of their burrow.
Image: Patrick Honan
Source: Museum Victoria

Unusual among insects, instead of laying eggs, females of this species give birth to live young. The female giant burrowing cockroach will produce up to 20 live young and she will care for them for up to a year. Juvenile cockroaches reach maturity at about three or four years of age and best of all apart from being the heaviest cockroach in the world, these amazing cockroaches can live up to ten years.

Giant Burrowing Cockroaches are permanently on display under the 'Diversity' exhibit in Bugs Alive!.

Further reading:

Henderson A., Henderson D., & Sinclair J. 2008. Bugs Alive: A guide to keeping Australian invertebrates, Museum Victoria pp. 47

Rentz D.C.F. 1996. Grasshopper country: the abundant orthopteriod insects of Australia, University of New South Wales Press, pp. 225-228

Rugg D. & Rose H. A. 1991. Biology of Macropanesthia rhinoceros Saussure (Dictyoptera: Blaberidae). Annals of the Entomological Society of America, Entomological Society of America, pp. 575-582

Links:

Question of the Week: How to sex a cockroach

Question of the Week: Cockroaches

Bug of the month

Author
by David P
Publish date
1 September 2011
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Comments (1)

Prior to becoming a keeper with the Live Exhibits team at Melbourne Museum, my knowledge of grasshoppers was quite limited. Locusts were probably the type of grasshopper of which I was most aware, due to their high numbers during the warmer months. They are also responsible for the must-have car fashion accessory adorning the front of vehicles, in the form of flywire to stop cars from overheating. In truth, locusts are just one of an estimated 700 species of grasshopper in Australia.

Common Toad Hopper The Common Toad Hopper (Buforania crassa) is an inquisitive creature.
Image: David Paddock
Source: Museum Victoria
 

Live Exhibits keeps many different types of grasshoppers and I am quite intrigued by them all, but the species which first caught my attention was the Common Toadhopper (Buforania crassa) from Central Australia. They are not particularly big - females are approximately 60mm long and males 40 mm long - and contrary to their name they rarely hop or jump, preferring to walk around. They have been described as an inquisitive grasshopper and that is what drew me to them. As with pets at home, if you are looking after an animal and you buy it a new toy or feed it a new food then you hope that they will enjoy it or get a reaction from it. I found that not too long after I added food they would be on it or in it. This included pollen, orthopteran mix (made up of muesli, fish flakes and other ingredients), and various forms of foliage, such as abelia, emu bush, acacia, and callistemon. You soon find out that they have their favourites - I would say that callistemon is in the top two.

Common Toad Hopper eating callistemon Common Toad Hopper (Buforania crassa) eating callistemon, one of its favourite foods.
Image: David Paddock
Source: Museum Victoria
 

Like most grasshoppers, Common Toadhoppers use camouflage to hide from predators. As you can see from the picture, once they are perched on a rock or stick during the daylight hours they can be very difficult to see. If they are brought up on a light sand substrate then their colours will reflect that.

Common Toadhopper camouflage Common Toadhoppers are masters of camouflage. Their colours can vary depending on what colour substrate they are brought up on.
Image: Patrick Honan
Source: Museum Victoria
 

Camouflaged Toadhopper Toadhopper perfectly disguised to match the branch it's sitting on.
Image: Alan Henderson
Source: Museum Victoria
 

Their reproductive cycle is very interesting. Grasshoppers generally breed in the summer months with the male perching on the female's back, either mating or guarding her from other males. The female then deposits her eggs in the soft sand and plugs them with a foamy substance. Our toadhopper populations here at Melbourne Museum vary seasonally and in some enclosures we currently have none at all, but we can see where females have deposited their eggs. Grasshopper eggs are good at withstanding drought periods. Normal incubation time for Common Toadhoppers is 1-3 months but it can be as long as 1-2 years, the eggs simply waiting for the right conditions. We can recreate those conditions, simulating warmer days with longer heat and light periods, and heavy rain through flooding the enclosures with water. Then hopefully not too long afterwards, little toadhopper nymphs will appear and even though they may not live up to the second part of their name, these grasshoppers certainly love eating grass.

young Common Toadhopper. A young Common Toadhopper.
Image: Alan Henderson
Source: Museum Victoria
 

In the meantime, come along to Melbourne Museum and visit our male Common Toadhopper, featured in the arid section of our Habitats display in Bugs Alive!.

arid habitat display Toadhoppers are in the arid habitat display in Bugs Alive!.
Image: David Paddock
Source: Museum Victoria
 

Bug of the Month

Author
by Jessie
Publish date
1 August 2011
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The stars of the Bugs Alive! aquatic display Green Diving Beetles (Onychohydrus scutellaris) are remarkable for their ability to store air and dive underwater to hunt food and find mates. They are found Australia-wide and on warm nights are attracted to lights. Recently on the Gold Coast there was a report of thousands of these beetles coming into the lights on the foreshore and the ground around the lights was a black moving mass.

green diving beetle Adapted to a life in the water, Green Diving Beetles have streamlined bodies, paddle like hind legs with swimming hairs and an amazing ability to store pockets of air so they can dive under water for extended periods of time.
Image: Alan Henderson
Source: Museum Victoria
 

Although sometimes they can be locally common they are predators and tend to live in water bodies, like dams and lakes at densities that do not deplete prey numbers too much; once prey numbers get too low, these beetles fly to a new water body and establish themselves there.

Adults lay their eggs in the water where tiny predatory larvae hatch out. The larvae spend their entire larval stage in the water before digging into the muddy banks of ponds and pupating. Once mature, the adults can either hang out where they emerged or fly and disperse to other areas where the food source is more readily available.

Over the last 12 months in Victoria, like many parts of Australia, has had increased rainfall which allows the beetles to disperse and breed at a greater rate than over the last few years of drought. Live Exhibits staff are predicting a great summer for Green Diving Beetles and they may turn up a bit more often in the Melbourne metropolitan area. Live Exhibits staff will be heading out equipped with torches, nets and waders to see if we can hunt down these incredible animals.

Green Diving Beetles
Green Diving Beetles can be voracious feeders; here a group of them are feasting on a dead fish at the Melbourne Museum.
Image: Alan Henderson
Source: Museum Victoria
 

These beetles are active predators and scavengers and add a great degree of movement and colour to our Bugs Alive! display. As they forage they constantly return to the surface of the water to replenish their air supply which they hold under their elytra (wing covers). They eat other aquatic invertebrates and in the wild will sometimes attack vertebrates such as small fish and tadpoles.

Next time you are in Bugs Alive! check them out in the aquatic tank. They spend a fair bit of the day sitting motionless clinging onto foliage but once they get moving they can certainly swim fast.

Bug of the month

Author
by Chloe
Publish date
1 July 2011
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Comments (6)

This guest post is by Chloe, a Live Exhibits keeper at Melbourne Museum.

Garden Wolf Spiders, Lycosa godeffroyi, are commonly found on the prowl around Victorian gardens at night. They are modern spiders, or araneomorphs, in the family Lycosidae and they differ from many other spiders through their prey capture technique. Wolf spiders are active hunters that chase down their prey.

Wolf spider, Lycosa godeffroyi	Wolf spider, Lycosa godeffroyi
Image: Alan Henderson
Source: Minibeast Wildlife
 

During the day wolf spiders seek cover in vertical burrows, often utilising discarded invertebrate burrows, however they will dig their own if necessary.

Wolf spider emerging from its burrow Wolf spider emerging from its burrow
Image: Patrick Honan
Source: Museum Victoria

Wolf spider peering out of its burrow Wolf spider peering out of its burrow, using its posterior eyes
Image: Patrick Honan
Source: Museum Victoria
 

Wolf spiders are attractive spiders, ranging in colour from black to orange-brown with striking grey patterns on their carapace. Males have large bulbs on their pedipalps and females are typically larger and more robust than males. They are common throughout southern Australia in a range of habitats.

Wolf spider Wolf spider
Image: Alan Henderson
Source: Minibeast Wildlife
 

Males court female through a series of leg drums and vibrations while ‘dancing’ with his forelegs.  If the female is receptive she will allow him to approach.  The male will then present the female with a sperm package on one of his palpal bulbs, (as spiders do not have penises) which she will store and use to fertilise her eggs.

Female wolf spider carrying her egg sac Female wolf spider carrying her egg sac
Image: Patrick Honan
Source: Museum Victoria
 

Sometime after fertilisation the female produces an egg sac, which she carries with her (even while hunting) under her abdomen. 30 – 40 days later the eggs hatch producing up to 200 spiderlings. The spiderlings do not immediately disperse; instead they ride on their mother’s back for a few weeks.  When they are ready to fend for themselves they disperse via silk strands.

Female wolf spider with spiderlings Female wolf spider covered in her spiderlings
Image: Patrick Honan
Source: Museum Victoria
 

Female wolf spider carrying her spiderlings Female wolf spider carrying her spiderlings
Image: Patrick Honan
Source: Museum Victoria
 

Wolf spiders are not aggressive by nature; they will however defend themselves if provoked. The anatomy of their feet – they have three claws and no hair tuffs on the tips of their legs – means they cannot negotiate slippery surfaces. This makes them good pets because they are easy to house and care for in a glass jar or terrarium.

Wolf spider, Lycosa godeffroyi Wolf spider, Lycosa godeffroyi
Image: Alan Henderson
Source: Minibeast Wildlife
 

 

Links:

Victorian Spiders

Wolf spider infosheet

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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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