Patrick

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Patrick

Patrick Honan has sent spiders into space and helped bring the Lord Howe Island Stick Insect back from the brink of extinction. Now as Manager of Live Exhibits, he oversees all the living things on display at the museum, from tall trees to tiny ants.

Bugs within bugs, part 2

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by Patrick
Publish date
7 May 2014
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Like any group of animals (or people), populations of bugs are susceptible to disease, pathogens and parasites. At Live Exhibits we keep our populations free from parasites, but sometimes new bugs from the wild turn out to be Trojan horses filled with unwanted guests.

Tachinid fly pupae Tachinid fly pupae, newly emerged from the abdomen of a Rainforest Mantid (Heirodula majuscula), collected from Cairns, North Queensland. These flies are always fatal to the mantid.
Image: Patrick Honan
Source: Museum Victoria
 

The parasites not only kill the bugs themselves, but could get into captive populations and cause havoc. Most of them are easily controlled once identified, and occasionally we can even operate to remove the parasite and allow the host to lead a long and fruitful life.

parasitic wasp larva A parasitic wasp larva being successfully removed from the abdomen of a living Olive-green Katydid (Austrosalomona falcata) collected from the wild.
Image: Alan Henderson
Source: Museum Victoria
 

But often this is not so successful and the first sign of something wrong is the presence of two different species within an enclosure rather than just one. When you get to recognise the signs of parasitism, it’s often difficult to find individual insects in the wild that are not parasitised.

tachinid fly larva A tachinid fly larva emerges from a wild-caught Robust Fan-winged Katydid (Psacadonotus robustus). The only indication of infection was the abnormally large abdomen of the male katydid.
Image: Melvin Patinathan
Source: Museum Victoria
 

One of the most insidious is the Gordian worm, named after the Gordian knot of mythology. These are long, hair-like worms up to half a metre long which begin their lives in freshwater streams attacking aquatic insects. When the aquatic host, such as a dragonfly or mayfly nymph emerges into adulthood, it leaves the stream and is caught and eaten by a spider, cricket or beetle. The worm grows within its new host, filling up the entire body cavity until the host is 95 per cent Gordian worm.

Gordian worm emerging A Gordian worm emerging from an Olive-green Katydid (Austrosalomona falcata).
Image: Alan Henderson
Source: Minibeast Wildlife
 

When fully fed, the worm causes its host to become thirsty to encourage it to seek out water where the worm emerges and continues its life cycle, laying more than 10 million eggs. Earlier this year Live Exhibits staff collected eight huntsmans near Cape Tribulation, North Queensland, five of which produced Gordian worms over the next few weeks.

 

Video: A newly emerged Gordian worm and its host, Beregama cordata, from the #liveexhibits takeover of the Museum Victoria Instagram account.
Source: Patrick Honan/Museum Victoria

The relationship between parasites and their hosts is an evolutionary arms race – as hosts come up with more effective defences, the parasites evolve techniques such as behavioural modification to overcome them. This fascinatingly gruesome relationship can be the stuff of nightmares; inspiration for everything from zombies to the film Alien, proving that science is stranger than science fiction.

This is the second in pair of posts about parasites. Don't miss Bugs within bugs, part 1

References:

Askew, R.R., 1971, Parasitic Insects, American Elsevier, USA, 316pp

CSIRO, 1990, Insects of Australia, Volume 1 & 2, Melbourne University Press, Melbourne, 1137pp

Gauld, I.D., 1984, An Introduction to the Ichneumonidae of Australia, British Museum (Natural History), UK, 413pp

Matthews, E.G. & Kitching, R.L., 1984, Insect Ecology (second edition), University of Queensland Press, Brisbane, 211pp

Bugs within bugs, part 1

Author
by Patrick
Publish date
28 April 2014
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To support our collection of almost 100 invertebrate species on display at Melbourne Museum, Live Exhibits staff must occasionally collect bugs from the wild, and some of these can hold unwanted surprises inside.

Chalcid w A Chalcid wasp, newly emerged from the cocoon of its host caterpillar.
Image: Patrick Honan
Source: Museum Victorai
 

At least one in every ten insect species is a parasite on other insects. In Australia this adds up to several tens of thousands of parasitic insect species, all living their lives on the outside or, more commonly the inside, of other insects. Most of these parasites are wasps and flies, and most of their hosts are butterflies, moths and beetles.

Tachinid fly eggs on beetle Tachinid fly eggs on the outside of a doomed Leaf Beetle larva (Paropsis species).
Image: Patrick Honan
Source: Museum Victoria
 

Parasitic insects usually lay their eggs directly onto or into the body of their host, but may lay eggs on a food plant in the hope that they will later be ingested by a potential host. Once inside, the parasitic larva consumes the host’s internal tissues while the host continues to go about its business. The parasite usually avoids the vital organs until the last minute – then polishes these off and finally kills its host.

Aphid ‘mummies’ Aphid ‘mummies’ – aphids that have been parasitised and glued to the leaf by Braconid wasps. When fully developed, the wasps will cut a perfectly circular hole in the back and emerge as adults.
Image: Patrick Honan
Source: Museum Victoria
 

Parasitic wasps are able to find their hosts no matter where they might hide. In order to lay eggs on its host – Sirex Wood Wasp (Sirex noctilio) – Megarhyssa (Megarhyssa nortoni) can drill through 9cm of solid wood with its ovipositor (egg-laying organ). Megarhyssa females find their hosts using infrared detectors on their antennae; the outer bark of a tree is 0.5oC warmer where a larva lies underneath.

female Megarhyssa A female Megarhyssa (Megarhyssa nortoni) drills through a pine tree to deposit an egg on the Sirex Wood Wasp within.
Image: Patrick Honan
Source: Museum Victoria
 

A parasitic wasp will sometimes inject venom that paralyses the host but keeps it alive, allowing the wasp to hide it away for its offspring as a sort of living larder. A large wasp dragging a larger, paralysed, huntsman across open ground is a familiar sight during summer.

Pompilid wasp drags a huntsman A Pompilid wasp drags a huntsman (Isopeda species) from its hiding place under bark, before paralysing it and inserting an egg.
Image: Patrick Honan
Source: Museum Victoria
 

A caterpillar can sometimes dislodge a parasite’s eggs with its mandibles, but wasps usually lay their eggs just behind the caterpillar’s head where they can’t be reached. Many hosts are able to ‘encapsulate’ a parasite already inside their bodies, localising its damage and starving it of oxygen. When more than one parasite is laid inside a host, the larvae fight to the death within the host’s body for the rights to its organs.

wasp cocoons inside the empty shell of a Cabbage White Butterfly caterpillar Thousands of parasitic wasp cocoons inside the empty shell of a Cabbage White Butterfly caterpillar (Pieris rapae). Each cocoon will soon produce a tiny wasp that flies off to find other caterpillars to parasitise.
Image: Patrick Honan
Source: Museum Victoria
 

Parasites are themselves subject to attack from hyperparasites, insects that lay eggs inside an already-occupied host. The emerging larva seeks out the parasite in residence and burrows into its body. These in turn may be parasitised by superhyperparasites, and so on.

“Great fleas have little fleas upon their backs to bite 'em,

And little fleas have lesser fleas, and so ad infinitum…”

Augustus de Morgan (after Jonathan Swift)

The art of the bowerbird

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by Patrick
Publish date
17 July 2013
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You might spy an unusual new installation in the Forest Gallery as part of The Red Queen exhibition showing at MONA, the Museum of New and Old Art in Tasmania. The installation by English artist Toby Ziegler, entitled My vegetable love; Cultural exchange, is in the shape of a Utah teapot fashioned from the same material used by male Satin Bowerbirds (Ptilonorhynchus violaceus) to make their bowers.

Bowerbird with blue objects Jack, the older male bowerbird, interacting with the teapot bower.
Image: Jon Augier / Toby Ziegler
Source: Museum Victoria and MONA
 

The theme of My Vegetable Love is the interaction between the natural world (the Forest Gallery’s bowerbirds) and the artificial world (a computer-generated teapot), with the object itself being a hybrid between the two. The main theme of The Red Queen is ‘Why do human beings make art?’, and this component investigates natural animal behaviours that appear, to us, artistic.

Two juvenile bowerbirds Juvenile bowerbirds are also intrigued by Toby Ziegler's teapot.
Image: Patrick Honan
Source: Museum Victoria
 

It references a 3D mathematical model of a teapot created in 1975 at the University of Utah which has become a standard reference object in computer-generated imaging (CGI), and also as a regular in-joke in animated Hollywood movies. It appears somewhere in all Pixar movies and in the ‘Third Dimension’ episode of The Simpsons.

Utah teapot A modern render of the original CGI teapot created at the University of Utah by Martin Newell.
Image: Dhatfield
Source:  CC BY-SA 3.0
 

Juvenile and female Satin Bowerbirds are olive green, but males turn a deep blue upon maturity at about seven years of age. Jack, the oldest male Bowerbird, has lived in the Forest Gallery as an adult for 13 years. Errol turned completely blue earlier this year, after more than 12 months in transition from his juvenile plumage.

Errol the Satin Bowerbird Errol during his transformation from juvenile to adult plumage. His unusual patterning prompted many queries from puzzled visitors.
Image: Jon Augier
Source: Museum Victoria
 

A new webcam streams live video of activity around the teapot into MONA and our website. One of Jack’s old bowers is also takes pride of place in the gallery at MONA. The teapot will remain in the Forest Gallery as part of the exhibition until 21 April 2014.

 

 

You'll need Windows Media Player to view this video feed. Get Media Player

Links:

MONA

Bowerbird Cam

'Birds face off for balance of bower in exhibit' in The Age, 19 Jun 2013

The eels are back

Author
by Patrick
Publish date
28 May 2013
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Last week the Live Exhibits team went into the field in search of eels and other fish to restock the pond in Milarri Garden.

catching fish at night Live Exhibits keeper Adam Elliott demonstrates the best technique for transferring freshwater animals from nets.
Image: Patrick Honan
Source: Museum Victoria
 

Last year the iconic Short-finned Eels (Anguilla australis) living in Milarri pond were moved to the Forest Gallery water system while we repaired and resealed the pond. Now Milarri pond is back in operation and ready for new inhabitants.

Short-finned Eel Short-finned Eel
Image: Rudie Kuiter
Source: Aquatic Photographics
 

Prior to the Milarri pond works, regular eel feeding sessions were very popular with museum visitors, giving our staff the opportunity to highlight the importance of eels as a traditional food source for local Aboriginal people. In western Victoria, kooyang (eel) were trapped using woven nets in sophisticated aquaculture systems by the Gunditjmara people for thousands of years – one of the featured installations of the upcoming First Peoples exhibition at Bunjilaka Aboriginal Cultural Centre at Melbourne Museum.

staff catching fish for Milarri pond Left: Maik Fiedel in deep water, checking his nets. Right: Melvin Nathan ensures the eels are well looked after in holding tubs.
Image: Patrick Honan
Source: Museum Victoria
 

We collected the new eels west of Melbourne under permit, and we also caught other fish such as Tupong (Pseudaphritis urvilli), Flathead Gudgeon (Philypnodon grandiceps) and Common Jollytails (Galaxias maculatus) boost stocks in the Forest Gallery creek and pond system. These are just a few of the 50 or so species of freshwater fish found in Victorian waters.

Native Victorian fish Clockwise from left: Common Jollytail, Flathead Gudgeon, Tupong.
Image: Rudie Kuiter
Source: Aquatic Photographics
 

Freshwater invertebrates, particularly Glass Shrimp (Paratya australis) were also collected to kick start the food chain in Milarri pond. Yabbies (Cherax destructor) will soon walk across land from nearby ponds, and many other invertebrate species will fly in or colonise via new plantings or by adhering to waterbirds. Pacific Black Ducks (Anas superciliosa), Little Pied Cormorants (Microcarbo melanoleucos) and other birds will soon arrive under their own power.

fish in a bucket Young Jollytails and Glass Shrimp swim around under a Water Spider (Megadolomedes species).
Image: Patrick Honan
Source: Musuem Victoria
 

At the end of the collection trip, animal keepers Chloe and Dave released the eels into their new home, where they will live under the care of Live Exhibit staff for many years.

Man releasing bucket of fish Dave Paddock releases the last of the eels into Milarri pond.
Image: Patrick Honan
Source: Museum Victoria
 

Fish destined for the Forest Gallery must be quarantined for three weeks in tanks set up behind the scenes to ensure no parasites or pathogens are introduced to our resident fish population.

Live Exhibits lab at night Dave sets up Tupong in quarantine some time after midnight in the Live Exhibits Lab.
Image: Patrick Honan
Source: Museum Victoria
 

A range of fish species as well as Macquarie Turtles (Emydura macquarii) can be seen daily in the Forest Gallery at Melbourne Museum. Silver Perch (Bidyanus bidyanus) and eel feeding presentations will recommence at Milarri pond in September when the water starts to warm and the eels’ appetites return.

Milarri Garden and Milarri Walk are open every day of the year except Christmas Day and Good Friday. 

More on the Monarch

Author
by Patrick
Publish date
20 March 2013
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The Wanderer Butterfly, or Monarch, is probably the most recognisable butterfly in the world. It populates children's books and is the classical species used to illustrate insect life cycles. The Children's Museum at Melbourne Museum has housed enormous replicas of the Wanderer caterpillar, pupa and adult for the last 13 years.

Butterfly models in museum The giant butterfly, pupa and caterpillar in the Children's Gallery at Melbourne Museum.
Image: Patrick Honan
Source: Museum Victoria
 

Wanderer caterpillars feed on plants known as milkweeds. In Australia these include plants introduced from Africa and South America, such as Asclepias and Gomphocarpus. One of the most common is the Swan Plant (Gomphocarpus fruticosa), which may have been accidentally introduced as part of the regular trade between Australia and South Africa, or deliberately introduced for the 'silk cotton' to assist in hat making. This species is considered a noxious weed in some parts of Australia, and its abundance has been dramatically reduced by weed control programs, leading to a concurrent reduction in Wanderer populations around Melbourne.

Caterpillars feeding Caterpillars feeding on the Swan Palnt, Gomphocarpus fruticosa.
Source: Patrick Honan
 

Milkweeds contain poisons called cardiac glycosides which are absorbed by the caterpillars and used for their own defences. These poisons affect the hearts of vertebrates such as birds, inducing vomiting at half the lethal dose. Wanderers advertise the fact that they are poisonous to eat with contrasting patterns of yellow and black in the caterpillar, and orange and black in the adult. The chemicals are concentrated in the tips of the wings of adults, so any bird venturing a taste will cop a full dose and leave the butterfly alone.

Wing of butterfly. The warning colours on the hindwing of a Wanderer Butterfly. The black spot is the 'sex gland' of a male.
Source: Patrick Honan
 

The caterpillars themselves also become victims of their own food plants. Studies in the USA show that up to 30 per cent of very young caterpillars become glued to the leaves of milkweeds by latex in the sticky sap. And when its first bite ingests an unusually high quantity of cardiac glycosides, a newly-hatched caterpillar may become seized for ten minutes or more in a state of catalepsis before recovering.

Caterpillar feeding A late-instar caterpillar addressing the milky sap of Asclepias rotundifolia.
Source: Patrick Honan
 

Despite this, some birds such as Pied Currawongs (Strepera graculina) and Black-faced Cuckoo-shrikes (Coracina novaehollandiae) seem to be able to feed on Wanderers with impunity. The caterpillars are also attacked by a tachinid fly (Winthemia neowinthemoides), whose larvae feed on caterpillars from the inside, slowly killing them. In some areas, particularly coastal NSW and Queensland, these parasites account for 80-100 per cent of Wanderer larvae.

mating butterflies A male Wanderer overpowers the female (left) before flying off together and resting for several hours whilst mating (right).
Source: Patrick Honan
 

Mating by Wanderer Butterflies can be an aggressive experience. Males patrol patches of host plants, awaiting females. When females appear they are chased with great vigour by the males, often spiralling high into the air. Eventually the male may overpower her with the assistance of pheromones that cause her wing muscles to seize, forcing her to the ground where he mates with her. In Australia, breeding may occur year-round in the northern parts of the Wanderers' range, but in southern areas thousands of adults cluster together in trees after mating to see out the cooler months. Although not as spectacular as the roosting sites in North America that host many millions of butterflies, these clusters around Sydney and Adelaide are a memorable sight.

Female Wanderer Butterfly Female Wanderer resting during the day.
Source: Patrick Honan
 

Flight of the Butterflies 3D opens at IMAX Melbourne Museum on 21 March. 

Patrick's first post: Monarch or Wanderer butterfly

 

References

Orr, A. & Kitching, R., 2010, The Butterflies of Australia, Allen & Unwin, Sydney, 296pp.

Oyeyele, S.O & Zalucki, M.P., 1990, Cardiac glycosides and oviposition by Danaus plexippus on Asclepias fruticosa in south-east Queensland (Australia), with notes on the effect of plant nitrogen content, Ecological Entomology, 15:177–185.

Parsons, W.T. & Cuthbertson, E.G., 2001, Noxious Weeds of Australia, CSIRO Publishing, Melbourne, 698pp

Zalucki, M.P. & Brower, L.P., 1992, Survival of first instar larvae of Danaus plexippus (Lepidoptera: Danainae) in relation to cardiac glycoside and latex content of Asclepias humistrata (Asclepiadaceae), Chemoecology, 3(2):81-93

Wanderer or Monarch butterfly

Author
by Patrick
Publish date
8 March 2013
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Comments (7)

The Wanderer Butterfly is known overseas as the Monarch Butterfly, so named for being the King, or Queen, of butterflies. In North America they are also known as King Billies, after William of Orange. The Australian name of Wanderer comes from its remarkable habit of long distance migration. The scientific name Danaus plexippus was bestowed by Carolus Linnaeus, the father of taxonomy and inventor of the scientific naming system.

Adult female Wanderer Butterfly Adult female Wanderer Butterfly
Source: Patrick Honan
 

Although not a native to Australia, the Wanderer may not exactly be introduced in the usual sense. Wanderer Butterflies most likely arrived in Australia across the Coral Sea from Vanuatu or New Caledonia, carried by three cyclones in early 1870. This was part of a major expansion in distribution across the Pacific and Atlantic Oceans from North America in the late 1800s, probably due to a combination of environmental factors, human movement and natural expansion.

Wanderer butterfly feeding An adult Wanderer Butterfly feeding on Cat's Whiskers (Orthopsiphon aristatus).
Source: Patrick Honan
 

The first recorded observations from Australia were made in February 1871 in Queensland, followed by the first record from Melbourne in April 1872. It is possible that Wanderers had been making the journey to Australia since time immemorial, but only after Europeans established their food plants here could Wanderers establish.

Wanderer caterpillar The distinctive fleshy 'filaments' behind the head of the caterpillar are used as sensory organs.
Source: Patrick Honan
 

Wanderers have been seen at sea up to 500km from land and occasionally settle on passing ships. This is not unusual – with favourable winds, Australian butterflies such as Common Eggflies often end up in New Zealand. Wanderers have a cruising speed of about 30km per hour with bursts of up to 50km per hour when alarmed.

Wanderer Butterfly pupa. The wings of the adult can be seen through the walls of a Wanderer Butterfly pupa.
Source: Patrick Honan
 

In North America, Wanderers undertake a famous annual migration from Canada and northern USA down to Mexico and California, and then back again. The populations overwintering in the Oyamel Fir Forests of Mexico roost at densities of 10 million butterflies per hectare. Because the length of time required for the migration exceeds that of an adult Wanderer's life span, those arriving back in Canada are the descendents of those that left the year before.

Map of butterfly migration Map of the North American migration of the Monarch or Wanderer butterfly that occurs each year in autumn.
Source: Via the Frost Lab, Queen's University Department of Psychology
 

The secrets of the Wanderer migration in North America weren't fully revealed until the 1970s. Canadian Dr Fred Urquhart was fascinated as a child by the question of where all the Wanderers disappeared to during winter, and he and his team of volunteers took nearly 40 years to discover the answer. Professor Urquhart died in 2002 but his life-long search is the subject of the new film Flight of the Butterflies 3D. In Australia, Dr Courtenay Smithers from the Australian Museum began tagging Wanderer Butterflies in the 1970s using many volunteers from the broader community. His studies revealed that overwintering populations around Sydney and Adelaide move into Melbourne and surrounds during summer. This research continues, with many questions still to be answered. In certain years, for example, populations appear to overwinter in some parts of Victoria, such as Phillip Island and the Western Districts, without needing to move interstate, but more data is needed to confirm these observations.

Flight of the Butterflies 3D opens at IMAX Melbourne Museum on 21 March. 

Patrick's next post on these butterflies: More on the Monarch

References:

Clake, A.R. & Zalucki, M.P., 2004. Monarchs in Australia: On the Winds of A Storm? Biological Invasions, 6:123-127

McCubbin, C., 1970, Australian Butterflies, Thomas Nelson Ltd, Melbourne, 206pp.

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