6 SCALE INSECTS. 



known by their songs, are good examples. Not all of this 

 suborder are so conspicuous for size or music. In this 

 group there are nine families, the least of which, in numbers, 

 is by no moans the Coccidiie, which comprise the scale in- 

 sects, mealy bugs, bark lice, and many others with no fa- 

 miliar names. T. D. A. Cockerell, in a recent check-list of 

 the family, enumerates almost one thousand described 

 species of scale insects. Though classed together, they are 

 •quite irregular in many respects. The female is wingless, 

 and conforms to its order in having incomplete metamor- 

 phosis. The male is winged, possesses but one pair of deli- 

 cate transparent wings, the second pair replaced by hooked 

 balancers or halteres, resembling in this respect the flies, 

 and passes through the four stages of growth before 

 mentioned as complete metainorphosis. The inconspicu- 

 ous size, remarkable tenacity of life, and high reproductive 

 powers of these insects make them insidious and formidable 

 enemies of trees, both deciduous and evergreen, conse- 

 quently demanding close observation and a thorough knowl- 

 edge of their actions from the successful horticulturist. 



Those wholly unacquainted with any of the forms of 

 these insects can find some of the less injurious species by 

 looking upon the long-spined pine tree {Pinus strobus), 

 a favorite tree among the ornamental trees upon lawns and 

 along driveways, and upon the twigs and outer branches of 

 the elm trees. Search upon the willow close up under the 

 winter buds may reveal the presence of another species. 

 The form upon the pine will be more readily observed 

 upon the green spines as a small whitish oblong scale with 

 a very small light brown spot at one end. The one on wil- 

 low is much the same, and belongs to the same genus, Chi- 

 ouaspi.s. On elm are to be found the naked scales, so 

 called from freedom from cottony covering. These are 

 larger, more nearly round, and favor the bark of the tree in 

 color. 



In this paper the life-history given and species di.scussed 

 will be confined to the most destructive forms, the sub- 

 family L)iax])ina', or armoured scale insects. The females 

 are protected by a waxy secretion which renders them 



