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Stick nest

December 18, 2017

Recently we received a couple of queries about birds seen around Strath Creek which turned out to be Dusky Woodswallows. We then encountered the same species towards the end of the Upper Goulburn Landcare Network’s Rail Trail Nature Walk on 8th December. The walk was part of Birdlife Australia’s annual Challenge Count where teams of observers count the number of bird species and individuals in a chosen area during early December. It is the third year that the UGLN’s Chris Cobern has organised the event along a section of the Great Victorian Rail Trail near Cheviot, east of Yea.

Our small team was close to beating the 2015 species total of 35 when we came across a flock of woodswallows. We then noticed one visiting what appeared to be just a small bunch of sticks caught above the fork of a tree just a metre off the edge of the rail trail (photo at right). This was in fact the nest of a Dusky Woodswallow, and despite its dishevelled outer appearance and precarious position, it would actually be a neatly shaped and lined bowl for the bird to nestle into (main photo above).


A short distance further on we came across a second nest, again only a metre or so off the path, but this time in a more stable position. Foot and bike traffic is obviously not a deterrent to these nesting woodswallows!

And for the record, we ended up with a count of 208 birds of 36 different species.

To see a picture of what the juvenile birds will look like if the breeding is successful, see a previous post Woodswallows around.

Neither Mantis nor Fly…but feisty enough

December 13, 2017

This is the time of the year that insectophiles like myself start closely examining the young leaves of eucalypt trees. The leaves are a mecca for insects like eucalyptus beetles, emperor gum moths and cup moths to eat, play and mate on.

Mantis Fly 1-DSCN7017

It was on one casual gum leaf observation trip I came across the insect pictured above. It is a Mantis Fly (order Neuroptera) but it is neither a mantis nor a fly. The Mantis Fly is a type of lacewing. The mantis reference pertains to the large raptorial forelegs which the mantis fly uses to grasp prey. They are most active at night and are active predators hunting sizable insects.






Usually when photographing insects, at some point in time the insect gets sick of the camera lens getting closer and closer and takes off either by flying or crawling away or dropping to the ground. I was therefore surprised when this Mantis Fly decided that the best form of defense is attack and started to rake the lens with its forelegs (pictured right). Feisty!

I must learn to pick on someone my own size next time.

Fly on the wall

December 8, 2017

This rather large and strikingly-patterned fly was spotted resting on the brick wall of our house the other day. Thanks to fellow Focus on Fauna blogger Ronlit, we think it is a Golden Head Rutilia Fly, Rutilia argentifera. The species name argentifera would suggest silver, not gold, but perhaps it refers to the whitish/silver spots on the body, rather than the yellow head.

The Golden Head Rutilia Fly is primarily a nectar feeder, but was unfortunately not seen during our participation in the recent Wild Pollinator Count, a citizen science project which involves observing which insects visit a selected flower or group of flowers over a ten-minute period. What we did see is the native bee fly pictured at right (click on the photo for a closer look) which, with the help of Karen at the WPC, we think may be an Australiphthiria species. Bee flies (family Bombyliidae) are also nectar and pollen feeders and our example was seen on Sticky Everlasting, Xerochrysum viscosum. We tend to think of bees and perhaps wasps as the main plant pollinators, but flies also play a major role. In fact we’ve just learnt that flies won the most numbers in this spring’s Wild Pollinator Count!

Together with Ronlit’s previous post on Long-legged Flies, you can begin to get an idea of the wonderful diversity and value of flies (order Diptera) – there’s a great deal more than just blowies and bushflies!

Fairies in the foliage

December 3, 2017

I always thought that there were fairies in the foliage at my place. Quite often, especially whilst walking through grasses in Spring I would notice brief flashes of colour out of the corner of my eye but when I looked around saw nothing – until I looked closely.

Dolichopodid Fly 1-DSCN6336


The flashes of colour weren’t from fairies at all but from a group of insects known as Dolichopodid Flies (pictured). These flies have long legs, hence the alternative name of Long-legged Flies, and bright iridescent green bodies which when they are not moving seem to blend in perfectly with the foliage on which they are sitting.

The adults are predators feeding on soft-bodied insects such as aphids and mosquito larvae (depending on species). The larvae are ground dwelling and are also predatory.

So, they are not fairies but just like fairies are kind of pretty and useful to have around the garden.

Looks can be deceiving

November 28, 2017

Spring is the time for planting the vegie garden and with that comes the influx of insects all keen to lay eggs on the lush new vegetation. But not all insects are pests in the garden. Some insects and their young are beneficial and predate on those things that harm your plants. The difficulty is telling apart the good guys from the bad. This is made all the more complex because different insects develop in different ways.


The vegie patch – a predator playground

Take the preying mantis for example, one of the good guys in the garden. The mantis is an ambush predator. Both the nymphs and the adults wait motionless until prey comes within reach and then grab it with their raptorial forearms. Baby mantis are easy to recognise because they look exactly like the parent, only wingless and smaller (see picture left). Their lifecycle is known as partial metamorphosis (hemimetabolism). The young are called nymphs and hatch looking very similar to the adult. They grow larger through a series of moultings until the final moult when the winged adult emerges. Other insects that develop in this way include grasshoppers, crickets and earwigs.

Common Spotted Ladybird (Harmonia conformis) larva

Ladybird Beetles are a different proposition. Both the adult beetle and the larvae are voracious eaters of aphids and scale insects and may eat up to a hundred insects a week. They are also good guys in the garden. The problem is the larvae look nothing like the adult (see picture right). Like butterflies and moths, beetles go through a grub (caterpillar) stage after hatching. Then they pupate and emerge as adults. This is called complete metamorphosis (holometabolism). The trouble is the very beneficial Ladybird Beetle larvae look like pest grubs, ugly ones at that.

So be aware when you wage war on insect pests in your garden that you don’t kill your allies with friendly fire. Looks can be deceiving.

Now you see ’em…

November 23, 2017

The basic survival skills in nature are the ability to elude the predators hunting you and to remain unseen by the prey that you are stalking. There are many ways animals can do this but one of them is by camouflage, using shapes and colour to blend into the background. One has to wonder then what is happening when you see an extremely white spider sitting on a brown stalk of vegetation trying to catch a meal. Has evolution gone astray?

White Crab Spider (Thomisus spectabilis)

Observed at Murchisons Gap Lookout, the spider in question was a White Crab Spider (Thomisus spectabilis), pictured above. The White Crab Spider is an ambush predator. It waits within the structure of a flower and then grabs any pollinator that stops by. This may seem at odds with its striking white colour. This spider however belongs to a family of spiders, Thomisidae, which can change colour from white to yellow depending on the colour of the flower on which it is hiding. It does this by secreting a yellow pigment into the outer skin layers. The colour change can take up to three weeks to complete and about a week to reverse.

So on what was this spider perched? A dead stalk of St John’s Wort, a striking but unwanted yellow-flowered plant in the district. Like my dress sense, this spider’s colour is out of season. My next challenge will be to try and find one of these critters in full yellow dress.

Not more about lerps!

November 18, 2017

Psyllids are tiny winged insects that look like small cicadas. In fact both psyllids and cicadas are Hemipterans meaning that they are characterised by sucking mouthparts. Adult and nymph psyllids suck the sap of plants. The psyllid nymph extrudes a mix of wax and sugar-rich honeydew from which it constructs a shelter under which it hides from predators and parasites. This ‘house’ is called a lerp. Lerps provide a food source for a variety of birds such as pardalotes and bell miners and are also an indigenous food source.

Different species of psyllids build lerps of different structures and composition. The Sugar Psyllid (Glycaspis sp.) builds a conical sugar-rich lerp.  The Lace or Basket Psyllids (Cardiaspina sp.) builds a scallop-shaped lerp. A current infestation of them is causing the large-scale browning of eucalypt leaves in the district.

While on a bird survey with the Murrindindi Birdwatchers last weekend we found a grove of Red Box supporting a large population of White Clam Psyllids (Hyalinaspis sp.). If you look carefully in the photo above you can just make out the nymph underneath the lerp.   The White Clam Lerp presents as a white, flat structure and although there were many of them the trees and their leaves did not seem to be affected.

Peeling back the lerp revealed the psyllid nymph underneath (pictured right). It didn’t harm the nymph but there is a spot of house reconstruction needed!