The typical Genus _Syrphus_ is well represented in Australia by several fine species, all of which are aphid eaters, and fly about in the bright sunshine but shelter among the foliage at other times; whenever aphis appear the syrphid flies soon follow, and I have seen them round the aphid-infested briar bushes in countless thousands. _Syrphus pusillus_, figured in the Agricultural Gazette N.S.W. 1904 under the name of _Syrphus viridiceps_, is our commonest species found upon aphis-infested rose bushes, orchard trees, and wheat fields. It measures about ⅓ of an inch in length; has large reddish eyes, yellow face, and dull metallic green thorax with yellow scutellum; the darker abdomen is banded with three interrupted transverse yellow bands, and smaller marks on the apical segments. _S. viridiceps_ is a more slender form, with a green face; the whole of the thorax is shining lead colour, with fine yellow bands on the abdomen; the legs are dark, and the whole fly is lightly clothed with fine hairs. Both these species may be taken on the same bush, and both have a very wide range over Australia. [Illustration: =Fig. 146.=--_Syrphus viridiceps_ (Macquart). A common Hover-fly that destroys rose and peach aphis. (“Agricultural Gazette,” N.S.W.)] The Drone or Bee Fly, _Eristalis tenax_, is another common garden fly with a very wide range, and is an introduced European species. It measures over ½ an inch in length and is broad in proportion; the head and thorax are clothed with yellowish brown down, and the smooth shining abdomen is mottled with black and brown. The larvae are dirty white maggots with slender rat-tails at the tip of the body, and they live in all kinds of rotten or semi-liquid refuse.