Robber Fly

Robber Flies, sometimes called Assassin Flies, belong to the Asilidae family of insects and there are many species. They are large, bristly flies (flies have just one pair of functioning wings) that are fearsome predators of other insects which they mostly capture in flight. They also prey on spiders and ants. Most Robber Fly species are distinguished by their robust build, large eyes, and a hairy ‘moustache’.

Robber Flies inhabit urban parks and gardens, woodlands, and forests – wherever there are other insects and spiders to feed on.

They capture their prey with their hairy legs and strong claws. They use their large proboscis to inject the victim with a toxin and an enzyme that dissolves its innards. After ingesting the meal, there is only the exoskeleton of the prey left behind.

Because Robber Flies often take leaf-eating and sap-sucking insects for prey, they help keep populations of these pest species under control. Some references suggest they can bite us humans if they are mishandled, but they do not seek us out like blowflies and mosquitoes.

Trigger Plant

A Grass Trigger Plant 'meadow' on the slopes of Mt Baw Baw

The Trigger Plant, or more correctly, Grass Trigger Plant, Stylidium graminifolium, is a fascinating Australian endemic plant that in our district grows on the Baw Baw Plateau, behind the sand dunes of Westernport Bay and Bass Coast, and all sorts of places in between. It seems to like gravelly-sandy soils in open woodlands and heathlands. At certain times, some locations are awash with the pink flower heads and sometimes you can fluke an occasional white one.

The most ‘fascinating’ characteristic of the Trigger Plant is the way it has evolved to achieve pollination. Under the petals of the flower is a sensitive column that has a pollen ‘club’ attached to its end. When an insect is attracted to the nectar in the throat of the flower, the column is ‘triggered’ to rapidly spring upwards and ‘club’ the insect, covering it with pollen. The insect flies on to the next flower and spreads the pollen and the process is repeated.

A further fascination of this amazing plant is that some glandular hairs under the flower can trap insects giving rise to the argument that the plant may in part be carnivorous.

Grass Trigger Plants are readily cultivated. They have a long flowering period and make a perfect wildflower addition to any native garden.

What’s not to like?

Australian Admiral

The Australian Admiral butterfly, or Yellow Admiral, or just Admiral, Vanessa itea, is generally one of the first butterflies to appear in this district as the weather warms up a bit.

Admirals are a mostly fast-moving handsome species and are easy to identify among the range of ‘brown’ butterflies we have in southern Victoria. They tend to inhabit more open ground on the edges of woodlands, home gardens, parklands, etc.

Vanessa itea is endemic to Australia and New Zealand and there is a close relative, the Red Admiral, that is found in Europe, Africa and America.

Australian Admirals often feed facing down and can be found sometimes on the trunks of trees lapping on oozing sap. Adults are good pollinators of course as they visit a wide range of flowering shrubs seeking their dose of nectar.

The favoured host plant for the larvae is the Native Pellitory or Shade Nettle, Parietaria sp.

Long-billed Corella

A couple of long-bills visited my garden again today. As usual, they were amongst a small flock of Little Corellas that ‘drop in’ every now and then and resist my attempts at persuading them to evacuate the premises due to their usual destructive and noisy behaviours.

Long-billed Corella

‘Corella’ is thought to have indigenous origins but exactly from which language is not certain. ‘Garala’ from Wiradjuri is most likely, but ‘garila’ and ‘caralla’ are also quoted in historical references.

The Long-billed Corella, Cacatua tenuirostris, has adapted well to agricultural and semi-urban environments, particularly in western Victoria where they became, and still are in some places, significant pests around farms and other rural properties. Anecdotally they are steadily spreading this side of Melbourne.

Long-billed Corella - Birdata

That long upper mandible is used to dig for roots and bulbs. It isn’t hard to appreciate the damage that could be done to crops, orchards, even hard surfaces like outdoor furniture, with such a tool. There are many records of property owners trying to solve that problem by culling the birds by various means (careful – distressing images).

Corella numbers can fluctuate wildly according to conditions. If you think the flocks of Little Corellas in West Gippsland are of concern, have sympathy for some residents in WA in 1878 who estimated a flock size of 50,000 birds!

Little Corella                                           Long-billed Corella

In the 1970’s, in some parts of its range where their numbers were of concern, Long-billed Corellas were ‘officially’ trapped and sold to the pet trade. Ultimately this had the effect of birds being released, deliberately or accidentally, into new areas. Long-billed Corellas are long-lived with life-spans greater than 20 years. Many caged birds outlived their owners.

There are numerous references by federal, state, and local government agencies that provide advice on ‘Cockatoo, corella and galah wildlife management methods’, their efficacy notwithstanding.

 

 

 

 

Eastern and Crimson Rosellas

I guess it is because they are relatively common, but it has always seemed a shame that we often take these two beautiful endemic parrots a little bit too much for granted. I’m guessing that many birdwatchers around the world would be envious of the fact that these two beauties can often be found in our backyards. Depending on which is your favourite field guide, there are 6 to 8 species of rosellas, all endemic to Australia.

The name ‘rosella’ has interesting etymological origins. It seems that as early settlers journeyed from Sydney Town to Paramatta, they passed through a district called Rose Hill (now a densely settled suburb of course). They would regularly glimpse flocks of small green, yellow, and black ‘parrakeets’ with a red head and white cheeks. The settlers referred to the birds as Rose Hillers. ‘Rose Hiller’ ultimately became corrupted into ‘rosella’ which is what the bird was eventually named and of course they were seeing flocks of what we now call Eastern Rosellas.

Eastern Rosella: Platycercus eximius. ‘Platycercus’ = broad tail, ‘eximius’ = excellent. No argument with that.

Eastern Rosella

The Eastern Rosella is probably a more urbanised bird than the crimson and is usually easily seen in our urban parks and reserves, backyards, etc., however, easterns are never far from lightly wooded habitat. They mostly feed on seeds of the heads of grasses and herbs at ground level. Eastern Rosellas are quite conspicuous when they are feeding on the ground, but despite their colourful plumage, they can fly into the canopy of a eucalypt and become nearly invisible.

Eastern Rosella checking its nesting hollow

There are several races of Eastern Rosellas. Our Gippsland birds are the nominate form. They are usually seen in small family groups. Eastern Rosellas are a sedentary species and are mostly restricted to the lower altitudes. Like all our parrots and many other species, Eastern Rosellas need a decent tree hollow in which to breed.

Crimson Rosella: Platycercus elegans. ‘Elegans’ = fine, elegant, or handsome. Some say all three.

Crimson Rosella

Crims like to inhabit tall timbered woodlands and rainforests. Periodically they will venture into farmland and urban reserves. It is not unusual to find Crimson Rosellas on the edge of alpine regions – or in coastal woodlands. They feed both on the ground and in the canopy. Eucalypt seed is a favourite food but fruits, lerp, and pollen are taken as well.

Crimson Rosella bathing in a puddle

There are several races, sub-species or forms of the Crimson Rosella. It is not unusual to come across an eastern-crimson hybrid.

Hybrid Eastern-Crimson (on the right)

Crimson Rosella - yellow form

Potoroo

No, I didn’t see one here in West Gippsland – sorry. That would be good, wouldn’t it? A little earlier this year, I was privileged to be invited by Moonlit Sanctuary at Pearcedale to have an ‘up close encounter’ with these endearing little mammals.

The Long-nosed Potoroo, Potorous tridactylus, is one of four species in the genus. Both the Victorian Flora and Fauna Guarantee Act and the Australian Environment Protection and Biodiversity Conservation Act list the Potorous tridactylus as ‘vulnerable’.  Highly-fragmented populations exist down the eastern seaboard, western Victoria and Tasmania. Their principal threats are habitat destruction by us, and predation by cats and dogs (us again!), and foxes.

Interestingly, it is thought the decline of the dingo has contributed to the reduction of potoroo numbers – the potoroo is exposed to increased competition for food and shelter by animals such as kangaroos and wallabies, and to increased predation from feral cats and foxes.

At first sight, the potoroo is a bandicoot-like marsupial until it moves with a kangaroo-like hopping motion. They are mostly nocturnal and usually solitary animals. Their diet consists principally of fungi, roots, seeds, and invertebrates.

The Long-nosed Potoroo is a promiscuous and opportunistic breeder - they may have 3 or 4 pregnancies a year. The new-born joey will spend up to 4 months in its mother’s pouch.

Thank heavens for recovery programs like those at Moonlit Sanctuary.

 

 

 

Planthoppers

Planthoppers or leafhoppers are a sapsucking species that are generally unwelcome in the garden. There are many varieties - bugs, aphids, cicadas, leafhoppers, and scale insects, etc. – and they all belong to the order of Hemiptera. Despite their variety, they all have specialised mouthparts for piercing plant stems and sucking up the sap of the plant. If their numbers are great enough the plant will eventually die.

As they feed, planthoppers leave behind a coating of honeydew on the stem. The honeydew can attract beneficial insects like bees, or it can encourage the growth of sooty mould which damages the plant as well.

Hemiptera have three life stages – egg, nymph, and adult. Beetles, butterflies, and bees for example have four stages – egg, larva, pupa, and adult.

The moth-like Passionvine Hopper, Scolypopa australis, has a wide range of host plants with soft stems, native and exotic, apart from the obvious Passion Vine species. The adults with their transparent wings are typically just 6-7mm long.

The nymph of the Passionvine Hopper looks like a miniature cicada and feeds on the plant in the same way as the adult. They are often covered in tufts of waxy filaments extending from their posteriors giving them their name of fluffy bums. It is assumed that this is to deter predators by proffering them a mouthful of sticky wax.

The adult Green Planthopper, or torpedo bug, Siphanta acuta, has a bright green, flattened, triangular body. It holds it wings shut in a vertical position, resembling a small green leaf or thorn.

Like the Passionvine Hopper, when disturbed, the Green Planthopper springs away and flies off to another nearby plant, its camouflage properties rendering it almost invisible.

At 9-10mm, adult Green Planthoppers are a little larger than Passionvine Hoppers. The nymphs of Green Planthoppers also have waxy tufts extruding from their hindquarters. Both species are native to Australia but are found pretty much world-wide these days.

Many garden pest websites spend a lot of time referencing chemical control of these sap suckers. It would be nice though if we could rely on natural biological control. For example, some birds and other insects do prey on adult planthoppers, their nymphs, and their eggs. Large infestations can be dealt with by applying a weak soapy water solution.