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The Eyes Have It

February 20, 2019
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When you’ve seen a spider walking across the ceiling have you ever wondered what family it belongs to? Do you find yourself at a loss when dinner time conversation turns to arachnid identification? If the answer is yes, read on.

Spiders generally have four pairs of eyes – a main pair which have muscles to move the retina and are capable of forming images, and three pairs of secondary eyes which are fixed. The spatial arrangement of the eyes is characteristic of which type of spider it is. The chart to the left which I found on the web (no pun intended) shows the characteristic eye conformations associated with the various spider families.

One of the most common spiders out and about in the district, particularly at night-time is pictured below. A check of the id chart shows it to be… (see if you can work it out before reading the answer below)

of the family Lycosidae, the Wolf Spiders. Three pairs of eyes can clearly be seen on the front of the cephalothorax (the fused head and thorax section of spiders). The fourth pair of eyes hinted at in the id chart can easily be seen in the picture right, facing backwards. Wolf Spiders are excellent hunters. They have excellent eyesight and have many sensory hairs (see picture above) to enhance the sense of touch. These spiders do not build webs but rely on chasing down prey or ambushing them from their burrows.

As discussed in a previous blog, Wolf Spiders are easy to locate at night with a torch by their eye-shine. I wonder if you are really, really good whether you can id a spider at night using the multiple eye-shine and the id chart?

P.S. Of what family is this spider? (pictured below). Click HERE for the answer.

 

Talking about Quolls

February 17, 2019

Some years ago we were involved in an unsuccessful survey using hair traps to detect the possible presence of Spotted-tailed Quolls, Dasyurus maculatus, (pictured left) in Tallarook State Forest. After that experience we tended to conclude that the quoll was locally extinct and rumoured sightings were shelved in our mind into the same category as the Thylacine, black panther and even the mythical bunyip!

But recent survey work by the Australian Quoll Conservancy as part of the Victorian Quoll Project has thrown new light on the possible occurrence of quolls in our general area. The AQC project aims to establish a reliable and continuous survey program to determine Spotted-tailed Quoll numbers and distribution in Victoria. It also aims to foster greater awareness of the species through educational events with community partners.

Chris Cobern, coordinator with the Upper Goulburn Landcare Network, is one of a number of volunteers with AQC and reports that they have found scats in the Wallaby Creek area that have been positively identified as containing grooming hairs of a Spotted-tailed Quoll by ecologist (and scat analyser) Barbara Triggs, author of Tracks, Scats and Other Traces – A Field Guide to Australian Mammals. Remote camera deployment is also being used as part of the Victorian Quoll Project, and a yet to be confirmed photo of a quoll was recently recorded. In the Kinglake area Chris has obtained photos of the related Brush-tailed Phascogale (at right), but as yet no quolls.

The project findings reinforce the need for work being undertaken by the King Parrot Catchment Fox Control Project, and both Parks Victoria and DEWLP will be ramping up feral cat and fox control in the Kinglake National Park and Mt. Disappointment State Forest areas with a view to protecting the endangered quoll from the threats of competition and predation.

Alberto Vale, president of the AQC, is currently here on a trip from north Queensland and will be giving a presentation on the Spotted-tailed Quoll in Kinglake West this coming Thursday 21st February. The talk is jointly sponsored by Focus on Fauna and the Fauna and Toolangi group. All are welcome, but RSVP is essential – click on the thumbnail flyer at left.

And as to why it’s called spotted-tailed when in fact it’s spotted all over? All four of Australia’s quoll species have white spots on the body, but the Spotted-tailed is the only one with spots on its tail – simple really!

Black as pitch…

February 15, 2019

…is one of the many similes to describe the total absence of colour. It is a state rarely encountered in nature unless of course you take yourself deep underground. But I reckon that I have seen something close. The Black (or Blue) Hairy Flower Wasp (Scolia soror), pictured left, is very black and very hairy, hence the name. The wings, depending on the angle at which you look at them appear to be a deep metallic blue. At the moment they are hunting around for two things – food for themselves and food for their future young.

The adults are nectar feeders. Some of these pictures were taken at a Crepe Myrtle in the Pioneer Reserve in Strath Creek, where they were swarming the bush. After eating their fill, squadrons of them flew low across the ground, particularly over areas which were heavily mulched, including compost heaps and wood-chip piles. This is where Scarab Beetle larvae live. After mating, a female Flower Wasp searches for scarab larvae and when she find them, digs down, paralyses and then lays eggs on them. The hatched wasp larvae then consume the beetle grub.

It is no coincidence that this blog site was discussing Scarab Beetles about a month ago. At that time they were mating and laying eggs. The time for beetle eggs to hatch is between 7 to 35 days. And now six weeks on the Black Hairy Flower Wasps are mating and laying eggs (on the hatched Scarab larvae).

Everything is interconnected!

A Blue-banded Bee it is not

February 12, 2019

With all the excitement at our place recently about Blue-banded Bees I am seeing them everywhere…or so I thought. The insect pictured left (click HERE to see a previous blog about it) is a Sand Wasp (Bembix sp.). As it hurtles past doing its wasp-like thing it superficially looks (and sounds) like a Blue-banded Bee. Both are building nests at the moment – the BB Bee in dried mud (and lime mortar!) and the Sand Wasp, as the name suggests, in sand.

Sand Wasps can be found hovering over bare sandy patches looking for an appropriate place to dig a tunnel in which to build a nest. Using its antennae it assesses a site to make sure the sand is easy enough to dig in but stable enough to support a tunnel without collapsing. Once a site is chosen it braces itself on the two back pairs of legs and rapidly digs a hole using its front pair of leg as scoops (see picture above).

Once the tunnel is built the wasp flies off to catch and paralyse an insect, which it does in flight. For Sand Wasps the prey of choice are flies. The picture above shows a Sand Wasp carrying an immobilized March Fly back to the nest.  The fly is placed in the nest, an egg is laid on it and the tunnel is sealed. The picture right shows a Sand Wasp approaching the tunnel entrance carrying its prey.

This process was fascinating to watch but ended abruptly when Mac the dog, wondering why I was laying on the lawn for so long, came over and stood on the tunnel entrance. I was obviously focused on the wrong fauna.

A Lesson in Light

February 9, 2019

The topic of beetles has been getting a bit of a flogging on this website lately.  At the moment they are out in force, feeding on nectar-bearing flowers. The Stag Beetle pictured left (Lamprima sp.) is one of these. It is stunning and its visual appearance is due to two different processes of light.

A close look at the carapace shows that it is dimpled. When the beetle is viewed from above in the sunlight it looks like it is covered in tiny little LEDs. This is due to reflection. The sunlight striking the beetle simply gets reflected back but at all different angles due to the curvature of the dimples.

The shimmering colours on the beetle’s shell (pictured above) are due to a process known as diffraction. Sunlight striking the shell gets broken up into spectral colours (nominally red, orange, yellow, green, blue, indigo and violet). Those old enough will remember the album cover of Pink Floyd’s Dark Side of the Moon showing light being diffracted into the different colours by a prism. This process is also responsible for phenomena such as rainbows, the blue bands on Blue-banded Bees and the colourful eye-spots on some butterflies and moths.

Instead of a prism diffracting the light on the beetle’s shell there are grooves. For these grooves to cause light diffraction they have to be spaced at intervals approximating the wavelengths of the colours. For example the wavelength of green light is nominally 550 nanometres (550 millionths of a millimetre) so the grooves must be similarly spaced, much smaller than the eye can detect.

So what makes this beetle so colourful is not only its cute dimples but its groovy shell.

Meet the parents

February 4, 2019
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The handsome creature pictured to the left is the larva of an antlion. The habits of antlion larvae were described in a blog five years ago (click HERE). They hunt by creating funnels in the sand. When an unsuspecting creature (usually an ant) slips down the slope of the funnel, the antlion larva waiting hidden at the bottom grabs the ant and drags it under the surface. It then immobilises the ant, injects it with enzymes and sucks out the juices. If you want to see one, locate the tell-tale funnel in a bare patch of sand and gently blow into it. The larva will be revealed at the bottom of the funnel. The parents though are much harder to find.

During the warm summer nights we usually leave our unscreened windows open. Last week an adult antlion (pictured right and below) appeared in our bathroom. Adult antlions look sort of like a dragonfly, sort of like a damselfly…sort of. Like damselflies, antlions fold their wings along their body (see below). But that is where the similarity ends. Antlions have long clubbed antennae whereas damselfly antennae are very short (click on photo far bottom left). In flight the antlion action is ‘fluttery’ compared to the direct motion of a damselfly.

Damselfly

Adult antlions are nocturnal, which is why we rarely see them. The fact that their lifespan is measured in weeks rather than months doesn’t help either. Depending on the species adult antlions eat nectar and pollen or small invertebrates.

Even though you’ve now met the parents it’s hard to see the family resemblance in the larvae.

Is the coast clear?

January 31, 2019

One of the dangers of watching and more-so writing about nature is that one can tend to anthropomorphise what we see  i.e. assign human characteristics and behaviours to the actions of animals. Doing so however can sometimes make a good story.

Our property is populated by Garden Skinks (Lamproholis sp.), pictured left. Watering the veggie patch results in a stampede of the little critters from underneath the straw mulch. We even have a few that slip in and out under the patio doors and live inside the house.

Skinks are one of the five broad groups of lizards, the others being Geckos, Legless Lizards, Goannas and Dragons. Only geckos have a larger number of species. Skinks are typified by a shiny, snake-like appearance and include not only Garden Skinks but also larger lizards such as Blue-tongues. In Australia there are 11 species of Garden Skinks. They are found in eastern and south-eastern Australia.

Garden Skinks feed on small invertebrates such as insects and spiders. The ones in our house patrol the window ledges for flies and other insects trapped in the house behind the glass. They also make a meal of the plentiful Daddy Long-legs (Pholcus sp.) who set up their webs in the same location hunting the same food.

Is the coast clear?

Last week whilst being entertained by one of our resident skinks devouring a fly, we noticed it stopped eating and raced to the window looking out. Sliding past was an Eastern Brown Snake (Pseudonaja textilis), pictured above right, another one of our reptile neighbours.

Now I might be anthropomorphising but tell me it’s not checking that the coast is clear.