Over the last four years we have seen some weird and wonderful parasites emerge from our newly collected specimens from northern Queensland. The rainforest seems to be a hotbed for a wide range of parasites, in fact it seems amazing that some species are able to survive at all due to the high rate of parasitism we see within them.

On occasions it has been very frustrating to find a prized specimen writhing as a huge maggot eats it way out of its body. Flies, wasps, worms, and mantispids are among those parasites we have seen in action.

Yesterday a tiny black head was observed poking out of the abdomen of a dying katydid. The head retracted when it was touched, but after being left alone for 30 minutes a 37 cm Gordian Worm emerged from its depleted host. Gordian Worms lay their eggs in water, which ultimately find their way into the body of its host; in our case a katydid. The worm then develops to maturity by feeding within the body cavity of the host animal, by which time it has usually done enough damage to kill it. Amazingly at the time of emergence the host animal is often driven to find water, which the worm will then move into to breed.

The 37 cm long Gordian Worm and the katydid it just emerged from. Photo: Alan Henderson Souce: Museum Victoria

The tiny head of the worm which had been feeding internally on the katydid. Photo: Alan Henderson Source: Museum Victoria