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Insect origami

October 24, 2021
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Like most insect Orders the name for the group of insects that includes beetles is derived from two Greek words describing the insect’s wings. Coleoptera comes from koleus meaning sheath and pteron meaning wing. It describes the hard ‘shield-like’ outer wings that protect the more fragile flying wings underneath. All members of this order have two pairs of wings. The outer wings are known as elytra. When the beetle is in flight the elytra are drawn up and away to allow the flying wings to unfurl. For most beetles the elytra cover the entire length of the abdomen.

Rove Beetles (pictured above) comprise a group of insects where the elytra are significantly shortened. In the natural world the Rove Beetle family comprises the largest number of organisms in a single group. As such they are widely varied in their habits and distributions. These beetles in our district are typically varied combinations of black and red. The elytra usually only cover the first few segments of the abdomen.

The majority of Rove Beetles, both adults and larvae, are voracious predators feeding on insects and other invertebrates. The Devil’s Coach Horse (Creophilus erythrocephalus), pictured left, feeds on maggots (fly larvae) and can be found in carcasses of mammals. They neither bite nor sting humans but contain a powerful toxin that can cause contact dermatitis when touched.

It is wrong to assume that due to the small elytra the rove beetle has small flying wings and is therefore a poor flyer. The picture right shows a Rove Beetle with its flying wings extended. When at rest the beetle needs to undertaking a complex folding manoeuvre to store its flying wings under the red elytra.

Insect origami.

Illegal Immigrants

October 19, 2021

House sparrows (Passer domesticus) are a native bird of Europe that has been introduced to many parts of the world, including Eastern Australia. They are not established yet in Western Australia, and that State wants to keep it that way. There is a hotline for anyone sighting a House Sparrow in WA and they will send out professionals to ‘disestablish’ them.

Back in the years when we used to travel, I was visiting Port Hedland in WA and in a touch of glorious irony, I was standing outside the Immigration Detention Centre in Port Hedland when I saw a small group of House Sparrows at the edge of the car park.  In this place where “illegal immigrants” were to be detained, some feathered ones had flown in. I rang the hotline and felt insulted when the person at the other end asked, Are you sure they are House Sparrows? Hmmph! I’m from Victoria.

Once the most common of introduced birds, House Sparrows are now in serious decline. They’re hard to find in Great Britain, in India, and getting less frequent in Australia. No one is sure just why – one study blames the rise of the mobile phone.

I still have a small flock at my place; they like our chook pen and the food it provides. I learnt an interesting fact about House Sparrows.  The male sports a fine black bib that functions much the same as the blue on male Superb Fairywrens: the colours are rich and bright in the breeding season but fade or dissipate in the off-season. Except for the Alpha males; these are dominant, at least 3 years old, high in the pecking order and carrying enough testosterone to sustain breeding colours in the non-breeding season.

In any flock of sparrows, watch out for the cock sparrows that have the biggest, blackest bib. They’ll be strutting and swaggering, shoving the commoners aside.

Cock sparrow in breeding plumage: black beak, and black bib

Related post Attention Entrepreneurs!

The Greeblies are coming!

October 13, 2021

Non-breeding plumage

Any one who has been cycling in the last month knows it is nest-building season and has run the gauntlet of magpies protecting theirs. On a more sedate note in our local dams Australasian Grebes (Tachybaptus novaehollandiae) have been quietly constructing their own nests.

Australasian Grebes are freshwater birds. During winter the plumage is quite plain (see photo left) but as breeding season approaches the birds display distinctive plumage (see photo below) including a yellow facial patch, a darker head and a striking chestnut stripe extending from the back of the eye down the neck (see photos below).

Back from Bunnings

In early spring the breeding pair accumulate reeds and grasses (pictured right) and constructs a floating nest tethered in a body of still water away from the shore. This is to protect the adult birds and the eggs and chicks from land based predators e.g. cats and foxes. The eggs take about three weeks to hatch so in a couple of weeks expect another blog on the arrival of the greeblies.

Breeding plumage

Grebes are good swimmers and divers (tachybaptus in the scientific name is Greek for rapid dipper). It is hard to get good photos of these birds because when approached they dive under the water and resurface many metres away. Quite the opposite of what happens when approaching a magpie nest.

We’re just never happy!

Rakes and Crails

October 7, 2021

Crakes and rails are small, skulking birds that hang out in reed-beds and are hard to find. They should be in any location that has a muddy edge on shallow water with lots of reeds to shelter in. Like this Spotted Crake I observed in a wetland in Barham NSW.

Water bodies that have steep sides and no mudflats or reedbeds are not likely habitats, even though many people think lakes like that are more picturesque. Yea Wetlands has some suitable areas at times, and I was quite excited to see that someone had recorded sighting a Lewin’s Rail in March this year on eBird.org, complete with a photograph of the bird partially hidden by reeds. (You can check the records and photographs here.) Rails are twice as large as crakes which are tiny, sparrow-sized waders.

Next time I was down in the area, I could see nothing in the reed bed but I did hear a persistent call which I thought was the Lewin’s Rail. I got out my phone and recorded it.

When I played this back a couple of times, to my absolute delight, the bird responded then came to the edge of the river and I got some good views of it among the reeds. Alas, I had no camera.

Why are these birds called ‘rails’? According to the etymology dictionary, it is from an old French word “raler“, meaning ‘to rattle’ and reflects their calls. (Just as crake comes from the old Norse kraka because it croaks like a crow.) Based on the recording I made, I would not object to anglicising the name and calling it a Lewin’s Rattler.

New Kid in Town

October 1, 2021
Crescent Honeyeater

Twice now I have detected this new bird in my backyard, giving an animated and loud vocal display. It is a Crescent Honeyeater  (Phylidonyris pyrrhopterus). Maree found them on Junction Hill in this post in 2019. Never recorded in Yea before. The first time in late August, it attracted the local bullyboys and was driven out by two Red Wattlebirds with cheering on by some spinebills and fairywrens. Today it was back unimpeded, calling loudly on a cold sunny morning from the top of a bush. Both times it has been a single male bird (the female has more muted colours all round).

Guess he’s no longer the New Kid in Town.

Better than a dog!

September 21, 2021
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The Huntsman Spider is one of the largest and quickest spiders in Australia. Some people may be disappointed to know that there are in fact many species of Huntsman Spider.

One of the most common, pictured left, is the Social Huntsman (Delena cancerides), the latter word derived from the Greek for ‘crab-like’, a description of the sideways walk it sometimes displays. This spider is very flat allowing it in nature to live under the bark of trees, often in groups of up to 300. In the house it can neatly slip into any crevice.

The Badge Huntsman (Neosparassus diana) is smaller but thicker than its Social counterpart. The young are born green but as they mature become brown to orange in colour (pictured right). The name is derived from the distinctive ‘badge’ marking on the underside of the abdomen (pictured below), easily seen if you can ‘coax’ the spider to walk on glass. The marking is displayed aggressively to deter possible predators, a feature known as aposematic colouration.

Like all Huntsmans, Badge Huntsmans have two rows of four evenly spaced eyes, the two outer eyes on the lowest row being the largest. The Badge Huntsman is distinguished by a patch of white hairs between the two rows that look like eyebrows (pictured below).

This is the time of the year when female Badge Huntsmans are out looking for mates, subsequently laying eggs in a silken cocoon held in a nest of grass held loosely together by silk threads.

At the moment I share my kitchen with a Badge Huntsman. Smaller than a dog it looks after its own feeding requirements and since it hasn’t shown me ‘the badge’ I am assuming it is happy with the arrangement. In covid times, a welcome companion.

Let the dogfights begin

September 12, 2021

As the weather warms up the airspace above your local dam will again become the scene for dogfights between competing dragonflies. The largest family of dragonflies, Libellulidae, contains members with descriptive names such as Skimmers and Perchers. Perchers are brightly coloured and as the name suggests spend much of their time ‘perched’ on a reed or stick overlooking their territory.

The Wandering Percher (Diplacodes bipunctata), is one of the commonest dragonflies in Australia and is distributed across the mainland (not Tasmania), New Zealand and Papua New Guinea. They perch on objects emerging from the water and if disturbed will fly off and briefly hover before settling again. Young dragonflies are yellow in colour but mature to be red (male) or orangey/brown (female, pictured below).

The Black-faced Percher (Diplacodes melanopsis), pictured right, can be found perched near still or sluggishly moving water. Even more colourful, the Scarlet Percher (Diplacodes haematodes) has a bright red abdomen with no markings.

Male dragonflies are highly territorial. They will aggressively drive off other dragonflies and other insects that intrude into their airspace. For perchers in particular there is fierce competition for the best place to sit, used for sunning themselves and overseeing productive feeding areas. There is also competition, particularly near water for areas with the correct plant species and substrates for the female to lay eggs on, although perchers tend to lay eggs by dropping them from the air.

Watching the high-speed antics of dragonflies on a dam is a wonderful way to spend a warm afternoon. If you don’t have any of these colourful creatures around your patch of water I believe you can rent them. The process is called Hire Perchers.

And the Winner is…

September 6, 2021

There’s been a ruthless ecological tussle happening before our eyes. A well-established species has been trying to hold on with the influx of a sassy new arrival.  They occupy the same niche, build similar nests, forage for similar food.  This town’s too small for both to flourish.

Spotted Dove (Streptopelia chinensis) photo from Birdlife Australia

The Spotted Dove was introduced to Australia in the 1860s and flourished in urban environments. Its origin is in China and India. I think it was introduced because it is good to eat, but we stopped eating wild pigeons a long time ago. It has dominated the ground-foraging, seed-eating pigeon role probably displacing the Bronzewings. They have been a useful disperser of seed and an important prey species for Goshawks and Falcons. Their nest is a flimsy platform in a bushy mid-level tree.

Enter the New Kid in Town. Once only found in arid inland Australia, the Crested Pigeon has begun to multiply and spread rapidly. It is one of a handful of native birds that have flourished in our farms and cities.  They have gradually extended their range in all directions and are now increasing in number even in Melbourne.

I noticed them becoming more common around my home. I saw the Spotted Doves nesting last year in a bushy paperbark tree. But they were outnumbered whenever they were foraging. There was no aggression, no pecking or nest-destroying. But somehow the Crested Pigeon has won. The Spotted Dove has gone. This year, I cannot find one in the district.

Crested Pigeon (Ocyphaps lophotes)

Confucius says…

August 29, 2021

If something is not eating your plants your garden is not part of the ecosystem’. With Spring nigh, expect critters particular young insects to be hatched and hungry. And your treasured vegie garden will not be the only target.

If you look carefully at new gum leaves at the moment you will find ‘flotillas’ of caterpillars of the Gum-leaf Skeletoniser Moth (Uraba lugens). An adult moth will lay between 100 and 200 eggs, twice a year. The resulting caterpillars (see picture left) eat only the surface layer of a leaf on both sides before moving on to the next leaf, leaving the gum-leaf veins – hence the name.

Apart from what they do to leaves the caterpillars are easy to identify because when they moult the head capsule of the exoskeleton remains attached to the body. With successive moultings the structure becomes larger and more distinctive (pictured above).

Despite what Confucius says, those in the timber industry regard these caterpillars as pests. Thinking about it I am not sure that Confucius did say that but he could have.

Don’t swat that mozzie!

August 9, 2021

Through open doors mozzies will zoom in
Attracted by odour of human
Whether O, A or B
She drinks blood like tea
It helps produce eggs, I’m assumin’

I have mixed feelings about mosquitoes. I know they are vectors of some terrible diseases and responsible for about 700,000 deaths a year. I know they are very irritating when they sneak in to bite my ankle in the dark.

But that’s not all mosquitoes – not even a majority. As a group, mosquitoes are primarily sap feeders. Both male (they’re the ones with feathery antenna and no biting mechanism) and female mosquitoes land on grass stems or leaves and suck sap.

In their favour, they provide a bulk snack food for bats – though one moth provides more nourishment than many mozzies. They are believed to help pollinate some plants, though Australian evidence is not definite on this point. They are certainly eaten, both in the larval and adult stages, by many wetlands creatures. Dr Cameron Webb of Sydney Uni says they have been unable to find any plant or animal completely dependent on mosquitoes but they are a sign of a flourishing wetland ecology.

The female only needs one feed of blood in order to be fertile.
The eggs are laid on water (typically, not always) where they hatch into a ‘wriggler’. They go through a few growth phases as they eat algae and microbes in the water. The pupal stage is less active. They are the bigger ones in the photo. They are curled up like a comma and swim down to the bottom if movement is detected above.

Without leaving the water, the adult emerges from the pupa supported on the meniscus of the water. It flies away and mating often happens within a few hours. The males fly together in complex dances in a swarm, and the female bustles into the middle looking for a mate. It’s like a night-club!

She needs the blood for the extra protein to form eggs. It’s unfortunate for us that in obtaining that tiny few drops of blood, they leave a great itch and sometimes leave viruses like the Ross River fever virus or Murray River Encephalitis, or much worse things in tropical areas.

Mosquitoes are consequently very hard to live with but I doubt whether our ecosystems could exist without them.

Pupa centre, larva on right

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I used to scoop the wrigglers out of this backyard pond with a sieve, but for now I’m letting them live. They might attract more frogs, bats, dragonflies, and birds.

I don’t want those bad disease-bearing mosquitoes to give all mosquitoes a bad name. I’m going to give these guys one more chance.