INSECTS AND PLANTS 73 



means by various washes and insecticides, and this fact 

 has led to less attention being paid to natural methods 

 of control. Eight species of true parasites are known in 

 America, and of predaceous insects, practically all the 

 native ladybirds devour the scale. 



One species of ladybird was introduced from China and 

 Japan by Mr Marlatt, and, although he imported a large 

 number, all but two died on the voyage or during the first 

 winter. The two survivors, however, nobly rose to the 

 occasion, and, during their first summer in America, re- 

 warded their sponsors with a brood of five thousand 

 individuals, a sufficient stock from which to rear colonies 

 for despatch to various states in the three succeeding years. 

 A small colony, sent to Georgia in 1902, increased to a 

 number estimated approximately at forty thousand by the 

 following summer, and, incidentally, materially lessened 

 the numbers of the San Jose scale : a consummation not to 

 be wondered at, for although the adult Chilocorus similis, 

 for that is the ladybird's name, feeds actively on the scale, 

 its larvae are apparently never satisfied, feeding incessantly. 

 Five or six scale insects a minute is what may be termed 

 the eating rate of a Ckilocorus larva, and an average of 

 only one a minute would give a total of one thousand four 

 hundred and forty a day. Ckilocorus similis, however, 

 was not destined to repeat the triumphs of its Australian 

 relative, Novius cardinalis, against the cottony cushion 

 scale. The success of artificial remedies against the scale 

 placed Chilocorus in an invidious position, and, as if that 

 were not sufficient, a native parasite arose, after its first 

 year in America, and practically exterminated it in some 

 parts. 



CODLING MOTH 



Wherever apples are grown and where in the temperate 

 regions do they not occur ? " wormy apples " are known. 

 They and their contained grubs are familiar to everyone, 



