Water Scorpion grow to over 50mm long they can extend the tube on their backs out of the water to breathe air like a snorkel while swimming. They can ambush fast swimming prey such as small fish catching them between their front legs and stabbing them with their pointed probiscus. Known as Toe-biters able to inflict a nasty nip although this specimen played dead when disturbed. Water Scorpions are also capable fliers and inhabit waterholes over much of Australia.
” A beetle not a bug. It is certainly one of the diving beetles in the family Dytigcidae, but there are a few black and yellow genera and species. This beetle could be in the genera Megaporus or Sternopriscus.” Found in the dam feeding on small aquatic organisms.
One of perhaps 3-4,ooo species of this family occuring in Australia. Its larvae feed as a parasite internally on other insects. On sunny days in summer the adults often rest on smooth Eucalyptus trunks and similar structures such as pipes and poles.
I.D. courtesy of Martyn Robinson. Naturalist. Australian Museum.
Further reading; http.www.brisbaneinsects. com/brisbane_flies/FlowerFeedingMarch.htm.