The Cuckoo Wasps – some of nature’s artworks

More Lockyer Valley wildlife

Large Cuckoo Wasp – Stilbum cyanurum (Vinegar Hill)

Some of the most spectacular wildlife in the Lockyer Valley isn’t necessarily the big stuff like kanagroos, koalas or kookaburras.  The small stuff can be absolutely entrancing.

The Large Cuckoo Wasp above is one example.  It was found dead on the floor in our house (hence the bits of detritus caught up in its exoskeleton).  Before you start thinking that we are a bit casual with our housekeeping, the critter itself is less than 20mm long, so the “fluff” is actually fairly minute particles.  Having said that this species is so small, it is known as the Large Cuckoo Wasp, which suggests that in general Cuckoo Wasps are pretty small insects.

Just how small they are can be seen in the image below.

20160103_Cuckoo Wasp_GFC_P1000969_small

The individual in the photo at the top of this page is on the right here. The one on the left is a different species (one of the two shown below). This Australian 20 cent coin has a diameter of 28mm.

The females of these wasps parasitise the nests of mud wasps, laying their egg in the mud nest next to that of the host species.  If they are discovered in the nest they roll into a ball like an armadillo, to protect themselves from the sting of their much larger host with the armour plates of their outer skeleton.  It seems to be a common feature of Cuckoo Wasps that the surface of the exoskeleton is pitted; perhaps to increase its strength, or to foil the probing sting of an angry mud wasp?  The defensive posture is often also used if they are threatened in some other way – such as a human trying to capture them.

The “appendage” at the rear is the ovipositor, used for laying eggs.  I’m curious about the structure of this ovipositor – you’d think that an insect that just lays its egg in the open nest of another wasp wouldn’t need something as robust as this to do the job.  Some other species of parasitic wasp have large teeth on the ovipositor in order to ‘drill’ through wood to reach their host(1).  For example, in the sawflies the ovipositor is saw-like and is used to insert the eggs into plant leaves, stems or wood(2).  Is this a relic from a previous evolutionary stage?

Large Cuckoo Wasps feed on the nectar of flowers in the woodlands, heaths and urban areas which are their habitat.

For a beautiful image of this species, have a look at this shot from Stanley and Kaisa Breeden.

After we found the second, smaller Cuckoo Wasp (dead on a window ledge in the house), and than another small one, I contacted Ken Walker at Museum Victoria and offered to send him the specimens to be identified.  Ken was happy to do this and to send me photos of the specimens.

Not only did Ken take fantastic photos, he also spent a lot of time cleaning up all the dust and debris off the specimens and then “relaxing” them so that they could be properly displayed.  Compare the photo on the left immediately below to the one at the top of this post – they are the same specimen.

Here are some of his photos.  These are photos of the most “diagnostic” parts of the bodies.  The scale bars for the whole body photos are 5mm for the top photo and 2mm for each of the others.

Stilbum cyanurum

Stilbum cyanurum (Photo Ken Walker)

Praestochrysis lusca

Praestochrysis lusca (Photo Ken Walker)


Chrysis lincea

Chrysis lincea (Photo Ken Walker)

You can find more about this species at the following links:



Thanks to Ken Walker from Museum Victoria for his willing assistance with identifying these species, and for the many other times when he has provided helpful advice on invertebrate wildlife.  Ken is the driving force behind Bowerbird, a huge job which he undertakes in addition to his many other duties, and he manages to produce the monthly issue of the Bowerbird Bugle newsletter.

The Soup Kitchen is open again

Following the bushfire (more on this later) that burned out about 80% of our bush 13 days ago, there is very little food for the our wallaby population.  As in the 2009 fire, we have set up a “soup kitchen” to tide them over until enough grass comes through to feed them.

The menu is simple: water (we always put out water pots for them because it is very dry here on the sandstone ridge), pony pellets, and racehorse-grade lucerne (alfalfa).  They much prefer the pony pellets over the lucerne, which is OK with us as the pony pellets cost $10 per bag, while the top-grade lucerne is $10 per bale wholesale and would not last as long as a bag of pony pellets if they decided to eat it.  Any leftover lucerne will make good mulch for the garden.

It’s hard to know how many wallabies we are feeding. They come and go for much of the day and all night, but there are four feeding stations, and there are sometimes 3-4 animals at each at the same time.  Probably nearly half of the females coming to the food are carrying well advanced joeys in their pouches.

Female Red-necked Wallabies at a feeding station

We set up a couple of camera traps (trail cameras) to check whether we are also feeding pigs and deer, but so far there aren’t any signs of them at our feeding stations.  We can see by their tracks that they are moving through our property from the National Park (also burned out) to get to the stone-fruit orchard next door.  The windfall fruit lying on the ground there are a favourite of the pigs, and the succulent leaves on the trees  attract the deer.  Our pony pellets and lucerne probably can’t compete with either of those.

One thing we did discover was that at a certain age the young male Red-necked Wallabies get around in a group.

A “gang” of young males takes over a feeding station.

In addition to checking for feral animals, the camera records provide us with great entertainment in the form of interactions between the wallabies, confrontations they have with possums, and views of joeys (baby wallabies) hanging their heads/tails/legs out of the pouch.

Wallaby vs Possum stand-off

Even the possums get possessive about the feeding stations sometimes.

Mother Brush-tailed Possum defends the feeder (and her young one) from an interloper

Some surprising things get into the camera trap images.  The data on the bottom right of the photo shows date (ddmmyyy) and time.

A bat zooms over one of the feeding stations – possibly a Flying Fox (one of the Megachiroptera).  Its image is distorted by the relatively slow shutter speed.

There is “green pick” coming up already in the burnt areas, and some of the wallabies are starting to feed there, though it would be hard work for a mother with a large joey in the pouch or “at-heel” to get enough of this to sustain herself and the joey.  Some of the females will have a joey at-heel but still getting milk from the mother, another in the pouch, firmly attached to a nipple, and another in the early stages of gestation, and their nutrient needs will be even greater.

We’ve had 69mm of rain since the fire went through, so the grass should come back relatively quickly.  We plan on starting to gradually reduce the food we supply in the next couple of weeks.