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Hidden treasures

May 9, 2017

We’re used to seeing small bats whizzing around at dusk over the summer period, but at this time of year you are more likely to come across one hiding sleepily in a wood-pile or even up the sleeve of a hanging overcoat, as we found a few years ago.

The microbat pictured here was one of a pair rudely disturbed from a state of torpor in a pile of wool-packs in our shed. It’s a Lesser Long-eared Bat (Nyctophilus geoffroyi) with its long ears curled down much more than if it were active.

The Lesser Long-eared Bat is at home in a variety of habitats and has a wide distribution covering most of Australia. It has adapted well to both agricultural and urban environments, with a willingness to use a range of different roost sites. However, tree hollows and bark fissures are its main natural roosts and, as with other microbats, scattered paddock trees and bush remnants play an important role as both roosting and foraging sites.

Below is another bat (we think also a Lesser Long-eared) found among some stored timber in the shed at almost the same time last year.

Thanks to Lindy Lumsden from the Arthur Rylah Institute for the identification.

The Kraken Wakes

May 3, 2017

The book (or was it the movie?) which most influenced my childhood was Day of the Triffids by John Wyndham. Even today I keep one eye closed when I watch meteorite showers just in case the story is portentous. Another book by the same author is The Kraken Wakes, the kraken being a mythical sea monster.

Well, you don’t have to go as far as the sea to encounter voracious aquatic predators. You have to look no further than your nearby lagoon or in this case horse trough. Judy from Limestone, the individual who recently brought us the maggot eating insects found in carrion has just sent in a photo of a water beetle devouring the floating body of a European Honeybee (Apis mellifera). This water beetle appears to be a Diving Beetle (Dytiscidae sp.).

IMG_0941.jpgDiving Beetles are regarded as beneficial insects as they predate on flies and mosquitos as well as their larvae. The adults eat a variety of insects, frogs and small fish and also keep the water clean by scavenging dead bodies (of animals!). The young of this beetle are known as Water Tigers and have been mentioned in a previous post. The back legs have a number of hairs on them so they can effectively swim and catch prey.

Enough about the beetle – I am hanging out to see which dead-devouring creature Judy comes up with next.

Laying mantis

April 24, 2017

Pruning in the garden can be hazardous for the pruner’s fingers, but in this case it was the well-camouflaged inhabitant of a shrub that was in danger from the secateurs of Susan at Strath Creek. She discovered, just in time, a praying mantid that was in the process of laying eggs, or at least constructing an egg sac known as an ootheca – see photos.

The ootheca is a spongy pouch that is glued to twigs or leaves and hardens to form a protective case for up to 400 eggs, depending on the species. The female uses appendages called cerci at the end of her abdomen to spin and shape the foamy ootheca. These cerci can be seen in the photo below.

Praying mantids (order Mantodea – meaning prophet) can sometimes be confused with other insects with elongated bodies such as stick insects, mantis flies and even some grasshoppers and crickets. Distinguishing characteristics of the mantids include mobile triangular-shaped heads with large compound eyes, strong forelegs with spines for catching prey, long thin antennae and, of course, construction of an ootheca. And a fascinating fact from Michelle Gleeson’s wonderful book Miniature Lives: “Praying mantids have a specialised hearing organ between their hind legs, allowing them to detect the ultrasonic calls used by bats to locate their prey. This provides mantids with an early warning system, giving them time to flee or drop to the ground before the bat can swoop.”

We won’t attempt to identify Susan’s praying mantid as there are about 160 species in Australia, most of which belong to the family Mantidae.

Generally speaking praying mantids should be welcome in the garden because they consume a variety of insect pests, such as aphids and thrips. But Susan will have to wait a while for an increase in her mantid population, because, depending on the species, the eggs can take up to 6 months to hatch!

[Just to clarify (or confuse?): both the terms praying mantis and praying mantid seem to be widely used interchangeably, although perhaps mantis should be confined to members of the genus Mantis, one of a number of genera in the family Mantidae?]

I won’t tell – part II

April 18, 2017

3rd instar

Last month I wrote a post describing how, for a number of reasons, I had secretly released some newly hatched insects into my wife’s vegetable garden. Of course my cover was blown when she happened to read the post in question (who would have thought!). However I got into serious trouble when soon afterwards the little critters which had initially disappeared turned up in great numbers as instars of the vegetable pest, the Southern Green Shield Bug (Nezara viridula) and proceeded to damage our tomato crop.

4th instar

The term instar is used to describe the larval form of insects that moult several times before becoming an adult. The number of instar states differs with species. This shield bug has 5 instar states (some are pictured) each of which last about a week. The lifecycle from the egg to hatching the adult is between four to five weeks.

5th instar

Like all bugs the Southern Green Shield Bug has piercing-sucking mouthparts. They pierce the plant or fruit and pump digestive enzymes into it allowing the bug to suck out the liquefied food. The surface area of the fruit around the puncture mark becomes brownish or black in colour and very often sunken, causing a dimpled appearance – not good for the market value of the fruit.

adult

As we are not selling the tomatoes I feel that there has been no harm done and we have progressed the field of science by identifying what insect the eggs were from.

That opinion is not shared in this household.

The Lady’s many costumes

April 11, 2017

Until recently Ladybird Beetles all looked the same to me but a closer look shows the lady has a number of outfits.

Common Spotted Ladybird

Ladybirds are a family of beetles (Coccinellidae) commonly found on roses and in vegetable gardens. They are considered beneficial insects as the adults and their young are voracious feeders of soft-bodied invertebrates such as aphids and mites but also consume flower nectar, water and honeydew from aphids.

Transverse Ladybird

The majority of ladybirds are red/orange and black but there are a variety of designs. Pictured are three such beetles found in our vegetable garden at the moment – the 23-spotted Common Spotted Ladybird (Harmonia conformis), the Transverse Ladybird (Coccinella transversalis) and the White-collared or Spotted Amber Ladybird (Hippodamia variegata).

Spotted Amber Ladybird

Fungus-eating Ladybird

 

Of course as any lady knows, if you want to stand out in the crowd you have to dress differently.   Also in our vegie garden is the yellow and black Fungus-eating Ladybird (Illeis glabula), pictured right. As the name suggests it feeds on fungus and black mold on leaves.

Vegetarians always stand out in a crowd!

Cute, but …

April 5, 2017

European Goldfinch – in Jean-Paul Gaultier outfit?

A property that adjoins ours abounds with blackberry thickets, some sprayed with herbicide in a half-hearted attempt at control. These thickets, both live and dead, currently provide great habitat for a large flock of European Goldfinches, estimated to be perhaps 100 or more. The goldfinches are primarily seed eaters and spend much of their time on the ground, but they are also often seen in among the blackberries, apparently feeding on the shrivelled berries.

And they are extremely wary, flying off in a swirling flock to the nearest tree when disturbed. This makes photographing them difficult, with our limited zoom capacity – thus the poor long-distance shots shown here.

Just a few of the large flock of goldfinches

Introduced as far back as the 1860s, the Europeant Goldfinch has not been as successful as some other introduced birds in spreading across the country, and they are mostly confined to south-eastern Australia.

It’s hard not to like these pretty little birds with their tinkling song (click on the audio bar below to hear it). Perhaps in recognition of this, the collective name for goldfinches is a “charm”.

A rather drab-looking immature goldfinch

But they do seem to feed on many weed species, dispersing the seeds as they move around. And we have seen very large flocks in this district feeding in the vicinity of, and presumably in competition to some extent with, ground-feeding native birds such as Red-browed Finches, Southern Whiteface and Yellow-rumped Thornbill.

So we feel a bit ambivalent about these birds – cute to look at and listen to, but, as with many other introduced species, we’d probably be better off without them.

For more information on the goldfinch, and a much clearer picture, go to BirdLife Australia’s Birds in Backyards website.

Searching for the Greeblies

March 29, 2017

A neighbour of mine has a farm dam. It has no fringing vegetation and therefore there is no place to hide for the hunted…and for that matter the hunter. Every year a pair of Australasian Grebes (Tachybaptus novaehollandiae) build a floating nest in the middle of the dam and successfully rear chicks. This year was no different.Australasian Grebe 1-DSCN3673

Recently the call came through that the eggs had hatched. The approach to the dam is tricky if you don’t want to alert the subject. One has to walk up the dam wall and peer over the top. On doing so I saw two incredibly small chicks splashing around on the dam. All it took was one squawk from the parent and the chicks disappeared. It took a while to find them but both chicks had hidden under the wings of the floating adult bird (see photos).Australasian Grebe 1-DSCN3675

Australasian Grebes are widespread throughout Australia. Still, shallow fresh water provides the ideal habitat. The scientific name Tachybaptus is derived from two Greek words tachys meaning fast and bapto meaning to dip in water i.e. fast-dipper. This perfectly describes the bird’s response when startled of diving under the water rather than flying away. If the young are under the wing when this happens they go for the dive as well.

I am not sure that Greeblies is the official name for young Grebes but it seems to fit.