38 DESTRUCTIVE INSECTS OE VICTORIA: 



Icei^a Purchasii^ then, is one of the very worst of the 

 known scale insects, and is, as Mr. Maskell states, allied 

 to Icerya saccharic which damages sngar-cane in the 

 Mauritius, but differing scientifically from that insect. 



There has been some discussion and a great difference 

 of opinion as to the real native country of this pest, and 

 I feel quite certain that its real hal^itat is Australia, and 

 probably Victoria, as more than thirty years ago it was 

 as common, if not more so, throughout the colony, and 

 especially near Melbourne, than it is at the present 

 moment. Now, as then, it subsists mostly on the branches 

 of the silver wattle, A. dealbata^ especially where those 

 pretty plants overhang a river. 



In the early days, in Victoria at least, no one thought 

 this pest to be capable of doing such enormous damage 

 as it has done, to oranges and lemons especially. For 

 upwards of twenty years specimens of its natural little 

 enemy, Lestophonus iceryce^ have been in the National 

 Museum collection here, these having been collected by 

 Mr. W. Kershaw, senior, one of our best collectors and 

 observers. 



The Lestophonus fly, the species named after its host 

 by Mr. A. Skuse, of the Australian Museum, Sydney, is 

 a small bluish-black fly (see Plate XIX., Figs. 6, 7, and 

 8), which makes great havoc amongst the gravid females 

 especially of the cottony-cushion scale, so much indeed 

 that anywhere around Melbourne it is often very difficult 

 to find a perfect specimen of the latter, the great majority 

 having been attacked by the Lestophonus insect. The 

 dense bushes of Pittosporum undulatum is a favorite 

 food plant of Icerya ; still the little fly seems to penetrate 

 into the darkest and most difficult crannies in the tree, 

 and the numerous holes from which the flies have escaped 

 from the body of the Icerya will testify to the destructive 

 powers of so tiny an insect. 



Of late years a small Hymenopterous insect (see Plate 

 XIX., Figs. 9 and 9a) have been found to attack the 

 cottony-cushion scale, my friend, Mr. Brittlebank, having 

 reared the insect from which he made the drawings fi*om 



