FIGHTING INSECT PESTS 



181 



trees were unfortunately infested by a few small degenerate 

 sap-sucking insects called, from the curious white waxen 

 egg-masses which they produce, cottony cushion scale insects. 

 These insects evidently found California and its orange 

 orchards congenial in climate, rich in food and devoid of 

 enemies for them, because by 1880 the cottony cushion scales 

 were so abundant and wide-spread as to be a serious pest. 

 By another ten years they had become a menace to the whole 



FIG. 89. The cottony cushion scale, Icerya pnrchasi, attacked by the 

 Australian lady-bird beetle, Norius cardinalis. (Upper figure slightly 

 enlarged, lower figure much enlarged; drawn from life.) 



orange industry of the state. 



In 1888 an entomologist was sent to Australia to hunt 

 for native natural enemies of the cottony cushion scale. 

 He found a very small red and black lady-bird beetle, called 

 Novius cardinalis, feeding on the cottony cushion scales, 

 and doing this so effectively that the scale insects were kept 

 within safe numbers in Australia. Almost all the lady-bird 

 beetles are "beneficial insects" in that their food consists 

 chiefly of other insects and mostly such injurious kinds as 

 plant lice and scale bugs. 



The entomologist collected a few of the little black and 

 red lady-bird beetles and sent them to California where 

 they were enclosed under netting with orange branches 

 infested by cottony cushion scales. The beetles began 



