When I went out to check the water troughs this morning, I was delighted to find a Diamond Weevil (Chrysolopus spectabilis) perched on a Silver Wattle. This gorgeous bug is also commonly known as the Botany Bay Diamond Weevil or the Sapphire Weevil. I like weevils. They look like tiny, humble elephants, with their lumbering gait and long snouts.
Weevils are the most successful and abundant family of creatures on earth. There are estimated to be over 10,000 species in Australia alone, with only 5,000 having been named. The Diamond Weevil has a proud history. A specimen was collected by Joseph Banks at Botany Bay during Cook’s voyage of discovery in 1770. It was the very first Australian insect to be scientifically described.
Diamond Weevils are specialist feeders, living only on a few species of wattle. Females lay eggs inside the stems. They hatch into grubs which feed on roots and then undergo metamorphosis. The adults or imagines (what a lovely name!) emerge during spring in all their brilliance. They are black, but beautifully patterned with palest, iridescent green. Put a Diamond Weevil on your hand, and it it so bright and shiny, one wonders how it ever escapes predators. But back on on the feathery, silver-green foliage of the Silver Wattle, it is surprisingly hard to see. The map above shows the distribution of the Diamond Weevil on mainland Australia.
Indian Mynas are one of the most invasive animal species in the world. Introduced into Australia in the late 1860s to control insects in market gardens, they have now spread to most of coastal Australia and New Zealand. Mynas are a serious environmental threat to native wildlife, taking over nesting hollows, evicting birds and small mammals, and preying on nestlings.
I admire these adaptable little birds, I really do. Their success is testament to their intelligence and devotion to their young. They are also great songbirds and mimics. Nevertheless, I am a member of a landcare group that routinely destroys these birds. I have personally trapped sixty six mynas at Pilyara in just three years, handing them over to be euthanased.
This makes me very sad. Each time a group is consigned to be gassed, I say a little prayer and apologise to them. After all, this isn’t their fault. We brought them here.They are innocent, just surviving – doing what mynas do, and making a pretty fair fist of it. And that, of course, is the problem. For one myna becomes ten in just three years. That means my sixty six birds would have become six hundred and sixty by now. Local wildlife could never cope with such an onslaught. So I continue my involvement with the program, and monitor the skies for mynas. I just never forget who the true culprits are.
Tall spikes of Pink Hyacinth Orchid (Dipodium roseum) are blooming all over Pilyara’s shady messmate gullies at this time of year. It is by far the most spectacular and abundant ground orchid on the property. As a Saprophyte, it has no leaves or green colour at all, hence no way to photosynthesise. Each stout reddish brown stem bears a spike of up to fifty delicate pink flowers, that resemble Hyacinths.
The Hyacinth Orchid relies on mycorrhizal fungi growing in association with eucalyptus tree roots to provide it with all the nutrients it needs. The plant reverts to dormancy as an underground tuber in late summer, when its life-cycle is complete. Seed capsules are sometimes produced and can be seen for several more months.
I am always fascinated by these sorts of symbiotic relationships. They demonstrate the vital, but often invisible interconnectedness of living things in our world. Any foolish person who tried to grow this showy orchid in their home garden would inevitably fail. It can only live in association with its specific fungus, and therefore cannot be cultivated.