190 Bugs, Cicadas, Aphids, and Scale-insects 



of kerosene and churning violently until a thick white cream is formed. 



Let this cool and jelly; it is the "stock," and will hold for a few weeks; when 



ready to spray, dilute stock with twelve 

 to fifteen times its own bulk of water 

 and spray finely over the foliage. The 

 spraying should be done when the 

 young scales are hatching and crawl- 

 ing about. They are then easily killed 

 by contact with even a single fine drop 

 of kerosene. For peach-trees dilute 

 the stock twenty times. 



Some of the scale-insects present 

 such unusual conditions of structural 

 modification and of habits that they 

 are, when first met with, difficult to 

 recognize as insects at all. The 

 waxen covering may be so irregular and 



FIG. 258. Female red orange-scale, Aspi- 

 diotus auranhi. (Photomicrograph by 

 George O. Mitchell; much enlarged.) 



curiously shaped that it gives no clue to the character of the enclosed insect 

 (Fig. 261), but seems to be simply a secretion of the plant in which the insects 

 are found. Or the globular shape and absence of distinct body-parts may 

 make the insects with their hardened blackish cuticle look like small plant- 

 galls; indeed certain scale-insect species were first described by botanists as 

 galls. Some scales live under ground, either in 

 ants' nests or independently; the curious so-called 

 "ground-pearls," small spherical shining bodies 

 found loosely scattered in the soil in certain tropic 

 regions, and really collected to be strung on threads 

 or necklaces, are the strangely modified bodies of 

 Margarodes formicarum, a scale-insect. Taken alto- 

 gether, probably no other family of insects exceeds 

 the Coccidae in the extremes of strange specializa- 

 tions. 



Closely related to the plant -lice and scale- 

 insects are the mealy-winged flies, constituting the 

 family Aleyrodidae. The adults (Fig. 262), except 



of two or three of the most abundant species, are 



i , , . i i , i L FIG. 2 so. Female 



rarely seen even by professional entomologists, but sca ie, Diaspis 



careful search will reveal in almost any locality the (Photomicrograph b y 

 curious little box-like elliptical bodies of the young ^uclTen^ged.^ 

 (Fig. 263), usually shining black, with pure- white 



waxen rods, filaments, or tufts. Examined under a good magnifier, the 

 wax-tufted cases are exquisite objects. These young mealy-wing flies look 



