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It is busy in ant world

March 12, 2020
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I am not a rock roller. When looking for invertebrates in the landscape I am reluctant to turn over logs or rocks to find things to photograph. Even if I gently put the rock back where I found it I feel that I am destroying something’s home, let alone the fact that the revealed critters could be squashed. I was therefore a little distressed when moving a load of bricks to find  I had disturbed an ant colony, even more so when it was the ‘nursery’.

Uncovering an ant nursery creates a flurry of activity. Ant eggs, larvae and pupae required specific temperature and humidity conditions to develop properly. If those conditions are compromised i.e. someone moving the bricks, the young are quickly moved to an area with the correct conditions.

Eggs, larvae and pupae

The pictures reveal a whole community at work. Female (wingless) worker ants (black) are assisted by unmated (winged) queens and drones to move the young from one area to another. The photo above shows a nursery of ant pupae. Unlike butterfly pupae, ant pupae develop with the appendages (antennae, legs) free. The eyes are also evident. As the pupae near ‘hatching’ they turn from white to pale grey. Newly hatched ergates (young, female worker ants) are light grey in colour (see photo).

The initial role of a worker ant is to look after the young by providing food or transport. As workers mature the tasks change to more energetic jobs like digging and clearing the nest. In the ‘twilight’ of their lives worker ants are given the more hazardous jobs like defending the colony or foraging for food. If they get killed – well, they were old anyway!

I’m glad our local IGA is a safe place to shop.

 

The lost and lonely

March 8, 2020

Twitchers (fanatical birdwatchers) lead a life of quiet desperation, always on the look-out for a ‘lifer’ – a bird species they have never seen before. This explains the phenomenon late last year when hundreds of bird-watchers flocked (pardon the pun) to the Werribee Treatment Plant after the reported sighting of a single Paradise Duck (a species rarely if ever seen in Australia) bobbing among the thousands of birds down there. Sometimes however that special bird comes to you.

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Susan who lives just west of Yea last week reported a Magpie Goose (Anseranas semipalmata) on her property and wanted to know if it was unusual in this area. This bird is neither a magpie nor a goose. The binomial name is derived from the Latin anser meaning goose, anas meaning duck, semi meaning half and palmatus meaning webbed – a half-webbed goose-duck, half-webbed referring to its feet.

Today Magpie Geese inhabit wetlands of northern Australia and southern New Guinea where they feed on water-based and land-based plant matter. Their range once extended this far south but due to systematic destruction of wetland habitas for agricultural purposes the bird has long disappeared from this landscape. Attempts have been made to re-introduce populations of Magpie Geese in the south – at Bool Lagoon near Narracorte, S.A. and in the Serendip Wetlands near Lara. The sighted bird could be a member of one of those populations, though still far from home.

So to answer the question, these days the appearance of a Magpie Goose around here is highly unusual. As Geoff our local bird guru said ‘it looks lost and lonely’. It was only around for a day. On the bright side, it may have been scoping out new territory for its mates – Yea Wetlands maybe?

C’arn the blues

March 4, 2020
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A ‘blue’ on Purple Loosestrife

A  recent blog described the Hesperiidae family of small butterflies, commonly known as Skippers. They are a relatively unknown group of small, generally orange/brown butterflies. Another relatively unknown family of butterflies is Lycaenidae, the Blues and Coppers, also called the Gossamer-Winged Butterflies. They are the second largest group of butterflies comprising about 30% of known butterfly species. The majority of Lycaenids in Australia exist in tropical areas. There are less than a dozen species in Tasmania. Most commonly around here this family is represented by small blue/grey butterflies which are frequenting flowers at the moment (pictured left).

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Common Grass-blues (Zizina labradus) mating

Ants tending an Imperial Hairstreak caterpillar


The distributions of species are highly localised reflecting the spread of particular plants that the larvae feed on and the relationship many species have with specific ants. Many butterflies of the Lycaenidae family have a beneficial relationship with ants (click HERE to read the previous blog about the Imperial Hairstreak). The caterpillars and pupae have a gland which releases honeydew, a sugar-rich substance secreted by a number of insects including hemipterans such as psyllids and gumtree hoppers. The ants harvest this honeydew and in return offer the caterpillars protection from predators and parasites. In some species the caterpillars enter the ants nest to pupate and the emerging adult has to find its way to the surface.

Even though larger butterflies are more easily seen, a careful look at your flowering plants at the moment will give you ‘the blues’, in a nice way.

Flight of the feather-horneds

February 25, 2020

For two weeks of the year, the last week in February and the first week in March (give or take depending on the season) the Feather-horned Beetles (Rhipicera sp.) take flight and the air is filled with these large, slow-flying insects (pictured below). The male sports large feather-like antennae which it uses to detect a mating pheromone emitted by the female beetle. The female beetle has simple rod-like antennae.

Feather-horned Beetle (Rhipicera femorata) DSCN6934

Little is known about these insects so to repeat a previous blog it is thought the larvae of this beetle are parasitic on the larvae of cicadas. The white patches on the exoskeleton are actually tufts of hairs. I think it is a case of a picture speaks a thousand words!

z Feather-horned Beetle (Rhipicera sp.) DSCN6905

My challenge this year is to take a picture of the female beetle. Not as impressive in the antennae department but a key part of the story.

More tales from the Swamp Gum

February 21, 2020

Following on from reporting about the tiny critters inhabiting the leaves and flowers of a local Swamp Gum (Eucalyptus ovata), the insects I was actually searching for also turned up – Flower Wasps. Regular readers of this blog probably think I obsess about Flower Wasps and they are probably right. They are my favourite insect.

As mentioned in many! previous blogs there is sexual dimorphism in Flower Wasps. The male wasp is winged and is much larger than the female wasp. The female wasp does not have wings so to get to the nectar rich flowers at the top of a tree such as a Swamp Gum it has to entice a male to mate with her. During and after that act the male wasp flies to the higher branches to feed on the nectar and the female wasp hangs on for the ride to also feed. It is one thing to read about and know this but it is truly magic to watch it in action. The local Swamp Gum being bent over offers that opportunity as the flowers are near ground level. Pictured below is a male (winged) and female wasp feeding (and mating) at the flowers. After feeding, the female wasp drops to the ground where it searches for beetle larvae on which to lay its eggs.

The vast majority of adult wasps are nectar feeders (and therefore pollinators). Another species turning up to feed at the Swamp Gum is also a regular to this blog, a Gasteruptiid Wasp. Pictured below is a male Gasteruptiid feeding. The female is recognisable by having a white tipped ovipositor about half the length of its body in size. Female wasps lay their eggs in the nests of Blue-banded Bees. They are a regular at the Blue-banded B&B.

This Swamp Gum could be a source from many stories to come – unless the heavy downpour last night washed out all the flowers. Stay tuned.

All creatures small and smaller

February 19, 2020

Very often we don’t spend the time to stop and smell the roses…or in this case smell the honey. Many eucalypts are flowering at the moment and you can be forgiven for not noticing given the flowers are pale yellow and high up in the trees. Locally there is a Swamp Gum (Eucalyptus ovata) with its crown bent over so that the flowers are at ground level. The heady scent of honey is attracting all sorts of critters, in particular wasps. So I have been staking out the tree to try and photograph some wasps for an upcoming talk.

Whilst sitting and waiting I noticed all manner of small insects also attracted to the rich nectar source. These I would not have noticed (you can get some idea of their size by comparing what they are sitting on) unless I had stopped and watched. Pictured left and below is an Ant Fly (Family Sepsidae), so called because they usually gather in large groups and from a distance look exactly like ants. The adults are nectar feeders. The one pictured is ‘bubbling’, the practice of evaporating all the water out of the nectar so that it can consume more of ‘the good stuff’. These flies are usually found around manure where they lay their eggs. The larvae are efficient composters of it.

Smaller still was this Chalcid Wasp pictured (right) on a eucalypt leaf. Again the adults are nectar feeders. Most species from this family of wasps are parasitoid – they lay their eggs on a live but paralysed host i.e. they are parasitic but resulting in the host’s death. Some species though are termed hyperparasitoid (now focus) they lay their eggs on the eggs of wasps that lay their eggs on a host. Small in size…large in confusion.

I wonder what the term is for a wasp that lays its eggs on the eggs of a Chalcid Wasp?

More Swamp Gum tales to follow!

A prickly story

February 16, 2020

Just after we put a post about Short-beaked Echidnas on this blog in early January, we discovered an echidna burrow with a puggle (young) in it only 30m from our house, and the adult featured in that post was most likely the mother. We only located the burrow when we noticed a small patch on an old pile of top-soil was moving up and down, as if it were “breathing”. When a bit of soil was brushed away, a creature with short sharp spines was revealed.

Puggle being fed

Puggle’s first outing


After setting up a remote camera, we were able to record the comings and goings of the mother over the next month or so, and occasionally watch her during the daytime. Her visits to the burrow were an average of 4 days apart (maximum of 7 days), and after uncovering the entrance and getting in with the puggle, she spent an average of 2 hours feeding it, before packing the entrance with soil and heading off to forage for ants and termites. With such intermittent feeding the echidna milk is necessarily very rich (imagine being fed only once a week!) and the puggle ingests up to 20% of its body weight.

When first discovered the puggle was probably about 4 – 5 months old, and is now almost fully spined and getting ready to leave the nest. In fact a few days ago we watched as the young one appeared and ventured off on its first little jaunt. It’s a bit wobbly on its pins, but a capable digger and very attuned to sounds and smells, immediately becoming a partially buried prickly ball when feeling threatened.

It eventually made its way back to the burrow and during its mother’s next visit we were able to sneak up and record the repetitive rasping sound of the puggle suckling on its mother’s milk patch (click audio below) as they lay only partially-buried beside each other.

There is limited knowledge and conflicting reports on echidna weaning. One reference has the young not weaned until about 7 months old after which mother and offspring may continue to share shelter sites and forage together until the puggle is 9 – 12 months old. Another reference states the mother has no further contact with her offspring after weaning it at about 6 months in mid-January to the end of February.

If the latter is the case, we can only hope our puggle’s natural curiosity is sufficient to let it find food and survive out in the big wide world, without heading onto the road!

More photos below:

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