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DISPLAYING POSTS TAGGED: entomology (13)

Plague Soldier Beetles

Author
by Jo
Publish date
15 January 2012
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Comments (143)

Your Question: What are these swarming beetles in my garden?

The Discovery Centre has received many enquiries over the last few weeks about swarms of beetles in suburban gardens in and around Melbourne; they are Plague Soldier Beetles, Chauliognathus lugubris.

Plague Soldier Beetles Plague Soldier Beetles
Image: Peter Saunders
Source: Peter Saunders
 

 

This flattened, elongated, soft-bodied beetle has a thin yellow-orange stripe across the back of the pronotum. It has metallic olive green elytra (hardened forewings), covering most of a yellow-orange abdomen. The legs, head, antennae and rest of the pronotum are black and the beetle is usually about 15mm in length. This native species has earned its common name of the Plague Soldier Beetle not as a result of bringing or spreading any dangerous plagues, rather due to its habit of forming huge mating swarms.

 

Plague Soldier Beetles Plague Soldier Beetles
Image: Peter Saunders
Source: Peter Saunders
 

 

The larvae of this species live in the soil and feed on soft bodied invertebrates, while the adults feed on pollen and nectar. The species is found across large parts of the country including urban areas and adults can be seen from spring through to autumn. During their mating periods they can appear in such large numbers that it is not uncommon for them to weigh down the limbs of weaker plants.

Their bright colour warns off predators as they are capable of releasing distasteful chemicals and would not make a good meal. For homeowners who may be hosting huge numbers of this colourful species, don't be too concerned, following the mating swarm the beetles tend to disperse.

 

Got a question? Ask us!

A moth flurry on the Murray

Author
by Mark Norman
Publish date
15 December 2011
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Comments (1)

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.

Cute creepy crawlies

Author
by Mark Norman
Publish date
3 December 2011
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Comments (3)

Mark is Head of Sciences at Museum Victoria. He's reporting back from Neds Corner in this series of blog posts.

The range of invertebrate animals that we found at Neds Corner was spectacular. At the robust end of the scale were the Rasping Crickets with their big jaws and impressive biting powers. We encountered pairs of these large crickets, the females having the long egg-laying ovipositor off the tip of their tail.

Rasping Cricket Rasping Cricket
Image: David Paul
Source: Museum Victoria
 

We also found the delicate pottery brood chambers built by potter wasps. They build these perfect small chambers to contain their young and then bring food to the developing grubs.

Potter wasp adult and nest Above: Adult potter wasp | Below: The nest of the potter wasp.
Image: Patrick Honan | Mark Norman
Source: Museum Victoria
 

Grace Lewis from the Entomological Society of Victoria witnessed the life and death tug-of-war between a spider wasp and meat ants over a paralysed wolf spider. The ants won.

Antlion larva and adult Above: Antlion larva in its conical pit | Below: Winged antlion adult
Image: David Paul | Mark Norman
Source: Museum Victoria
 

The ants were not so lucky in the many antlion pits we found scattered in the red sand. Antlions are the juvenile stage of an insect related to the lacewings (order Neuroptera). The young antlions with their big jaws dig a conical pit in the sand and sit in the bottom waiting for ants to slide in. The flying adults were attracted to our night lights. We also saw another related insect known as a mantis fly or mantispid – it has a lacewing body with the attacking front end of a praying mantis.

Mantispid Mantispid or mantis fly
Image: Mark Norman
Source: Museum Victoria
 

The centipedes were beautiful and fast, with lots of legs for running. We also found small red-eyed cicadas everywhere and saw them emerge from their wingless cases.

Colourful centipede Colourful centipede
Image: Mark Norman
Source: Museum Victoria
 

Dr John Stanisic of the Queensland Museum was pleased with his tally of ten land snail species including some of the smallest animals imaginable. Our photographer David Paul has perfected photographing "gliding sand grains".

Tiny land snail Tiny land snail
Image: Mark Norman
Source: Museum Victoria
 

Every day we found more radical colours, shapes and sizes amongst the invertebrate fauna than the day before.

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.

Links:

Parks Australia blog

Bush Blitz

Winning photo

Author
by Kate C
Publish date
18 July 2011
Comments
Comments (4)

A photograph by museum entomologist Dr Ken Walker has just won a coveted place in the annual international Leica calendar. In 2012, the company’s calendar will feature microscope photographs, and Leica put out a call for entries. Ken’s photograph of the head of a tiny, undescribed lichen moth in the genus Chamaita (family Arctiidae) was one of 12 selected.

male lichen moth The winning photograph of the head of a male lichen moth.
Image: Ken Walker
Source: Museum Victoria
 

The photograph, as well as being incredibly beautiful, is an important diagnostic tool.  This species is a pest in palm plantations in New West Britain, Papua New Guinea. To assist those who need to identify it, the species has its own page , featuring the winning photograph and others, on PaDIL (Pests and Diseases Image Library).

Says Ken, "It’s a great recognition for the photographic skills we have developed here over the past six years to have an image to be used in the high-quality calendar." The competition was open to anyone using Leica microscope and camera equipment; the prize is a Leica EZ4 dissecting microscope. This prize will go right back into PaDIL’s suite of specialist technical equipment to create more photographs like this one.

Links:

PaDIL

Dragonflies abound

Author
by Kate C
Publish date
9 March 2011
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Comments (0)

Last weekend's balmy evenings brought out a squadron of deadly aerial hunters in my backyard. I saw about ten dragonflies zooming around, plucking flying insects from the sky. It was an amazing sight – I’ve never seen so many in action in such a small area. From the half-eaten bodies I saw on the ground, it seems they were feasting on a swarm of young ant queens and males on their nuptial flights.

Dragonflies and damselflies belong to the 300-million-year-old insect order Odonata. You can tell the difference between the adults easily; damselflies are generally smaller, more delicate, and hold their wings together above their body when resting. Dragonflies are their beefy relatives and most rest with their wings held out to each side. As juveniles, odonates – known as nymphs – mostly lurk in freshwater ponds and streams eating smaller creatures such as mosquito larvae and small crustaceans.

Dragonfly eyes Compound eyes of a dragonfly.
Source: Museum Victoria
 

Adult dragonflies have incredible eyesight thanks to large compound eyes that wrap almost all the way around their heads. Combined with extraordinary agility, they are skilled hunters and snatch gnats, moths and flies from the air, eating them on the wing with their powerful jaws. They even mate on the wing; the male guards the female while she lays eggs in the water, grasping just behind her head with the claspers at the end of his abdomen.

dragonflies laying eggs in a pond A pair of dragonflies laying eggs in a pond. The male is holding on to the female just behind her head as she dips her tail into the water to lay eggs.
Image: Susan McBratney
Source: Susan McBratney
 

I love watching these animals and their amazing behaviour, which is reflected in the common names for some dragonfly families – hawkers, cruisers, skimmers and perchers. Another common name, darner, harks back to a medieval folk tale that they were the devil’s darning needles that would sew shut the mouths of unruly children!

Male scarlet darter (Crocothemis erythraea) male. Male scarlet darter (Crocothemis erythraea) male on the island of Crete. The thorax of the dragonfly is packed with powerful muscles that drive their wings. Unlike most other insects, dragonflies and damselflies can move each pair of wings independently of the other.
Image: Stavros Markopoulos
Source: Used under Creative Commons license CC BY-NC 2.0 from macropoulos
 

A lot of people have mentioned seeing more dragonflies than usual this season so I had a chat to MV’s aquatic insect expert, Richard Marchant, to find out more. He says that knowledge of Australian dragonfly biology is patchy, but they’re quite long-lived – nymphs might take one or two years to reach adulthood, and adults probably live a month or more and travel many kilometres. He believes that all the rain Victoria has received this summer means the increased areas of standing water has attracted dragonflies in huge numbers to many parts of the state, including the greater Melbourne area. So look up, and enjoy the stuntwork of these acrobats in the summer sky!

Links:

Infosheet: Dragonflies and damselfies

Australian Museum: Order Odonata

Devil's Darning Needle

600 Million Years: Giant invertebrates in the Carboniferous

Herald Sun: 'Bugs galore as Vic gets steamy'

A plague of locusts

Author
by Kate C
Publish date
7 December 2010
Comments
Comments (0)

You've probably heard reports that northern Victorian farmers are losing whole crops to armies of marching hoppers and that locusts are on their way into Melbourne. The species in question is the Australian Plague Locust, Chortoicetes terminifera, which belongs to the short-horned grasshoppers (family Acrididae). High rainfall over past months has created a bounty of lush green growth for the locusts to eat, allowing them to breed to plague conditions.

‘Locust’ is used to describe grasshoppers that can swarm in huge numbers. Most grasshoppers are solitary and the Australian Plague Locust generally shuns company too. But something interesting happens when their numbers build up: they enter what is known as a gregarious phase and their behaviour changes profoundly.

Juvenile locusts aggregate in ‘hopper bands’ that march across pasture, devouring everything in their wake. The adults travel vast distances in flying swarms that can be kilometres wide. A swarm that covers just one square kilometre can eat ten tonnes of vegetation in one day.

locust swarm Band of nymphs moving through pasture, as seen from the air.
Source: Museum Victoria
 

We spotted locusts on a recent trip to Benalla; they were all over the town, hopping and flying over roads and gardens in low numbers.

locust This locust was sunning itself on the footpath of the main street in Benalla.
Image: Nicole Alley
Source: Museum Victoria
 

In some species – such as the Desert Locust found in Africa, the Middle East and Asia – the gregarious phase displays very different colours and body form to the solitary phase. Not so with the Australian Plague Locust; the two phases look pretty similar, especially when they’re dry specimens and their colours have faded, such as those in our entomology collection.

pinned grasshoppers Plague locusts in the Museum Victoria Entomology Collection.
Source: Museum Victoria
 

Links:

Australian Plague Locust Commission

DPI Victoria locust information

DPI NSW locust image gallery

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