Compost critters

Brown Centipede
Centipede

Gardening is always a good way to come across the small wildlife around us and sifting compost can be among the most rewarding jobs in this way because it reveals many critters (‘bugs’, if you prefer) which rarely see the light of day.

Centipedes live in leaf litter and other moist shady habitats, and the one above was perfectly at home in the compost until we disturbed it. And why not? Cool, damp, dark, and full of small insects to eat … just about perfect. It wasn’t enormous but at just under 60mm long it was probably big enough to give someone a nasty nip and was treated with due caution during the photo shoot before being released. For more about centipedes, visit the pages of CSIRO or the Queensland Museum.

Fat white elephant beetle larvae are common in the compost, too, and we sometimes see larvae of smaller scarabs – or even the emerging adult, like this beautiful green one. We saw another of these today but it flew off before I could get a photo. All these beetles spend time underground as grubs and dig their way out after metamorphosing into their adult form. They sensibly wait until the soil softens before doing that, so they emerge in great numbers at the beginning of the Wet; we call the pretty ones Christmas beetles but I’ve got to say they are too late for that this season.

A few days ago I found a large beetle pupa (not a cicada nymph as I first thought and said) when I was emptying a plant-pot which had nothing much in it but weeds. We often see the cast-off exoskeleton of the cicada nymph, hanging on a plant like this with its back split open where the adult has emerged, and the elephant beetle larvae, but I had never seen either a living nymph or an elephant beetle pupa. One big difference which I should have noticed is that the cicada nymph has strong digging claws on its front legs but the beetle doesn’t.

Cicada nymph
Beetle pupa extracted from its underground cell
Cicada nymph on its back
Another view

This illustration of the beetle’s whole life cycle depicts a different species but the resemblance is clear.

Ouch?

Australia is known for the number and diversity of its dangerous wildlife. Crocs may come to mind first but we have spiders (red-backs and funnelwebs among others), snakes (over half of the world’s ten most poisonous species – one list gives us all ten!) and more.

I was helping clear up around a house on Hervey’s Range, in the hills forty minutes out of Townsville, on Saturday. We picked up an old door which had been on the ground near an outbuilding and saw a scurry. I scurried for my camera and was able to get this:

centipede
Centipede against the door it had been living under

The boards of the door are about 120mm wide, so the centipede is about 150 mm long.

Centipedes are not (strictly speaking) insects, since insects have only six legs, but are similar in many ways. They are predators, eating anything they can take, and have a pair of poison claws near the mouth to assist them. “Although a bite to an adult human is usually very painful and may cause severe swelling, chills, fever and weakness, it is unlikely to be fatal. Bites can be dangerous to small children and those with allergies to bee stings,” according to Wikipedia (which will tell you much more about them if you’re curious enough to click on this link). They need to be treated with caution but, like most animals, will not attack unless they have no better option. We allowed this one to get away … but we might be careful about picking up anything on the ground nearby in future.

Also under the door was the biggest spider I have seen in the wild. I know some folk don’t like them so I won’t put its picture here but clicking this link will take the rest of you to a group of shots of it on my Flickr photostream. It’s one of the so-called ‘Primitive Spiders’, a group (Mygalomorphae) to which funnelwebs, trapdoors and tarantulas belong. They are mostly ground-dwellers, as mine is. Many are large and hairy, as mine is, and some are very poisonous – and I don’t now whether mine is, but we treated her with as much caution as we treated the centipede.

And we had a great day and no-one got bitten. I did see some non-dangerous critters up there too – a wallaby, scrub turkeys wandering around, a huntsman which only looked small after the other spider, a hawk soaring overhead and insects including a robber fly, a small wasp, a brown katydid and many butterflies.