White Cedar tree and the caterpillar attack

Tree trunk covered with hairy caterpillarsOur urban ecology provides a rich tapestry of interdependencies and sometimes these relationships aren’t immediatly apparent.

The tree Melia azedarach (White Cedar, Cape Lilac) is a lovely tree. In Australia, it has the distinction of being one of the few that are deciduous. This is important for our home. It provides very welcome summer shade but lets in light throughout winter. It looks wonderful in flower and growing right next to the house it is visually important.

However, it has a flaw. It is attacked by one caterpillar species Leptocneria reducta. The caterpillar assembles a population often in the hundreds and they eat the leaves of the tree until there are no more.

caterpillar species Leptocneria reducta

Counts of moths collected under ultra-violet light from a local study suggest that they have two generations a year. I wouldn’t be surprised if it’s more. Often I find the trunk carpeted by the caterpillars, the ground beneath the tree is full of their droppings. Of course, this raises the question, what do you do?

Leaves of the tree showing caterpillar damageThere are no real predators. Apparently Tawny Frogmouths (I heard one a couple of nights ago) will eat them. We have watched the caterpillars completely denude our tree. At which point they crawl off in search another. It has to be a Melia azedarach, this caterpillar is a specialist species. When they devour our tree, they crawl into the house, behind curtains, everywhere.

Our solution is to fight them. Unfortunately, we have had a bottle of pyrethrum spray permanently parked next to the tree. I don’t like spraying, I don’t like pyrethrum and I worry about the food chain and the effect on other species. Our tree has Birds Nest ferns, Elk horns and orchid species growing in and on the tree, lots of habitat. We have lovely skinks and millipedes that also inhabit the tree and there is a chance that they will get sprayed. All in all, it’s a dilemma for us and a minus for a tree which is particularly nice.

However, there is a silver lining. In our urban setting, the birds that reside here are aggressive and dominate, new birds are a rarity. So when something new comes around, it sticks out. Last winter I had noticed a smallish shy bird come in to the garden. It would be gone before I could figure out what it was or what it was doing. After a while, I noticed it would take some food from around the ‘Cedar’ and noticed it was taking caterpillars. I finally managed to get one reasonable photograph of it. It is a Fan-tailed Cuckoo which ‘enjoys hairy-caterpillars in its diet’. Our urban ecology throws up fascinating examples of winners and losers and the caterpillar, a pest species, becomes an important bird attracting species.

Fan-tailed Cuckoo

So, now that it is late summer, I am going to leave the caterpillars that I photographed yesterday alone. Hopefully they’ll provide an abundance of food for the Fan-tailed Cuckoo and some more opportunities to observe this bird.

There is a great site for information on this and other Australian caterpillars http://lepidoptera.butterflyhouse.com.au/lyma/reducta.html

I am a big fan of Birds in Backyards website http://www.birdsinbackyards.net/species/Cacomantis-flabelliformis

Information about the tree can be found at http://www.anbg.gov.au/gnp/interns-2008/melia-azedarach.html which notes that Melia azedarach can be a weedy species. I would agree! I am constantly pulling young seedlings up.

Fowlers Gap

Emu-7095I have had the good fortune to be part of a research project at the University of New South Wales’ 40,000 hectare research facility, Fowlers Gap.

It is vast. It is in arid country, 100 kilometres north of Broken Hill. An incredible place, it encompasses a hilly range, the same one that Broken Hill is a part of, ephemeral Eucalypt dominated creeks and grass or copper bush dominated plains. David Keith, in his excellent book ‘Ocean Shores to Desert Dunes’ (More information on the book) describes two ecological communities that are present here. Gibber Chenopod Shrublands in the hills and Aeolian Chenopod Shrublands on the plains.

Grassland plain at sunrise


The plains are highly variable, sometimes Mitchell Grass dominated (pictured above), sometimes Maireana (Bluebush) and other times a mix. But, they are surprisingly diverse and it appears a healthy ecosytem supporting an array of wildlife. The Marieana, a Chenopod, has a fruit with wings ideally adapted for wind dispersal. I think the species shown is Maireana sedifolia.


Maireana bush

The hills are harsher. Feral goats compete with the Euro kangaroo and other wildlife so that it appears in places over grazed and hostile.


Emus and Broken Hill

Broken Hill town with dranmatic backdrop of mining wasteIt is isn’t everyday that you get to visit arid Australia. It is incredibly ancient, beautiful and harsh. I passed through Broken Hill, a mining town on an ore body. Named after a hill which appeared broken, but which is now a spectacular ‘slag heap’ backdrop to the town. It is a visually startling town.


I love the emus, though they are so common that for the people that I am with, they are just another element in the landscape. Amazing animals, the female is solitary for most of the year and uses all her energy to lay a clutch of up to twelve eggs. The male incubates them and raises the young.