THE APPLE-BAEK SCALE. 77 



CHAPTER XII. 



THE APPLE-BAEK SCALE. 



(Mt/tilaspis pomorum.) 



Order : Semiptera, Section Homopiera. — Family : Coccidce. 



Tins most formidable enemy of the apple-grower is an 

 importation from either Europe or America, and has long 

 been known in those parts as one of the worst pests 

 aiFecting the apple. 



The large family of the Coccidce are, unfortunately, too 

 well known, the life-history of most of them being very 

 singular ; and if only for the purpose of stud3dng their 

 habits with the view of endeavouring to find out some 

 weak spot in their economy so as to be able to take 

 advantage of it by preventative or remedial measures, the 

 time so devoted would, by the knowledge gained, be 

 amply repaid. 



Mr. Maskell, whose valuable work on the " Scale Insects 

 of New Zealand" is so well known, tells us that "the 

 male of this species is unknown in New Zealand and 

 Europe, and doubtful in America," so that although the 

 Mussel-scale of the apple is a well-marked species, its 

 resemblance to other kinds of the same germs feeding 

 upon certain native plants is so great, that to distinguish 

 them would require the aid of a specialist, otherwise 

 important mistakes in identification may happen. 



Every orchardist whose apple-trees are infested with 

 the Mijtilaspis will have observed both stem and branches, 

 and often the fruit also, to be covered with a small mussel- 

 shaped Scale of about one line, or less, in length (see 

 Plate VII., Fig. 1 ), the cluster generally being thickened 

 where a joint occurs in the branches ; these are the female 

 Scales, the male Scales, according to Professor Comstock 

 and others, being much smaller. I have not yet heard of 

 a perfect male having been found here. 



