79 



Scale triangular, greenish when fresh Acuminate Scale 



Covering cottony, sack containing insect globular, yel- 

 lowish Globular Mealy Bug 



Long, v,^hite, fluted cottony-sack at rear end of insect, 



which appears to stand on its head 



Full-Grozun Cottony-Cushion Scale 



HOW TO USE THE TABLE. 



Following the tabic it is not impossible to locate the names of 

 most of the insects therein without the use of instruments. In 

 the case of some of the insects, however, it is absolutely essential 

 to resort to mechanical aids. These are of a very simple charac- 

 ter and inexpensive. A pocket lense, the first requisite, may be 

 secured in any optical or photo-supply establishment for from 50 

 cents upwards. The uses of a pocket lense are so numerous 

 these days, especially to plant breeders and teachers, that none 

 should be without it. The use of the lense and' what observations 

 one can make with the aid of it are an education of no inconsider- 

 able merit. If the insect is active a small vial with a cotton or 

 cork stopper, or a glass with a cloth or paper cover, will be found 

 convenient. A penknife or pin is the other requisite, and the lab- 

 oratory is complete. Armed with these two simple implements 

 one can readily determine some of the finer points of structure 

 that had to be drawn upon for differentiation between closely- 

 allied species. An insect that is normally active, but stationary 

 at the moment of observation, can be induced to move with the 

 touch of pin or penknife point. One that is normally stationary, 

 however, will fail to respond to the hard point, and thus be 

 thrown into another portion of the table. 



Indentures are used' for the various groupings, so that when 

 the appearance of an insect does not correspond to the description 

 given in a certain line, we turn to the next line that is the same 

 distance from the margin. For example. Suppose v/e have be- 

 fore us the larva of the yellow-shouldered ladybird, but do not 

 know what it is. We turn to the table, where the first line reads : 

 "i. On very young, soft growth." Yes, we say, there is where 

 we found it. The next line reads : ''Dark, small, smooth-bodied, 

 winged ana* wingless, usually in large numbers." Now, our in- 

 sect may, after a fashion, answer to the entire description, but we 

 did not find it in "large numbers,'' hence we proceed to the next 

 line. ''Among the aphis usually." Yes, we found it "among the 

 aphis." The next line begins, "Stationary," but we have ascer- 

 tained after brief observation that our insect is not "stationary." 

 It is not the next one because is is not "green." Nor is it the next 

 one, because it is scarcely "alligator-like," and bears no "whitish 

 markings." We find the next line to read, "Brown, spiny grub, 

 over twice as long as broad," a description that corresponds fairly 



