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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.

Bubbling

March 20, 2017

At the moment Flowering Gums are swarming with insect pollinators. The greatest in number are the Honey Bee (genus Apis) but if you look carefully there are many smaller insects also buzzing around. Many of these are Australian native bees.

There are over 1600 species of native bee. Unlike honey bees which live in large colonies, many of the native bees are solitary. The female bee constructs a burrow either in wood or the earth. A single egg is laid in a cell which is then sealed. This process is repeated until the burrow is filled.

The egg is laid on a mound of pollen and nectar which acts as the food source when the egg hatches. Different native bees collect this pollen in different ways. Some collect it on combs on their legs whilst others collect it on the hairs on their abdomens. Certain types of native bee swallow the pollen and nectar. To concentrate this food source they undertake ‘bubbling’ – regurgitating the liquid mixture into a bubble to evaporate off the water (see photo below).

1-DSCN2960

It is a great opportunity to observe native bees because they remain stationary to do this, and they are usually such flighty critters.

I wonder if I could employ the bubbling technique at an all-you-can-eat smorgasbord restaurant?

It’s a wrap

March 13, 2017
by

All wrapped up

Spider and package on (wilted) oregano

You’ve no doubt noticed the current abundance of grasshoppers and also spider webs strung inconveniently across paths, the latter proving to be quite a trap for the former. Near our vegie patch we disturbed a Wingless Grasshopper (Phaulacridium vittatum) which jumped right into the web of what looked like a Garden Orb-weaving Spider (Eriophora sp.), which in a flash reached the grasshopper and wrapped it in silk.

A few minutes later it had transferred the package to the edge of its web, on a stalk of oregano, where it rested with its legs drawn under its body and stayed there all through the heat of the day. Although predominately nocturnal hunters, these spiders are clearly not going to knock back the chance of a good daytime meal.

European Wasp stealing the spider’s meal


 
 
At another web, we thought the spider had achieved a double whammy with a grasshopper and a European Wasp (Vespula germanica), apparently both caught together in the web. Closer inspection revealed that the wasp was not trapped but was in fact feasting on the grasshopper right under the nose of the spider, so to speak!

Giant Green Slantface caught


 
 
 
A third web nearby had ensnared a different grasshopper with the amazing name of Giant Green Slantface (Acrida conica), an insect we had come across previously. So although maybe not making a big dent in the grasshopper population, the spiders are certainly being well-fed.

Garden Orb-weaving Spider resting


Click on any of the photos for a better look.