INSECT PESTS 251 



Plant lice, or aphids. Plant lice are small, usually wing- 

 less insects, black, green, orange, or white in color, that are 

 found on the stems, the underside of the leaves, and even on 

 the roots of plants. They increase in number with incredible 

 rapidity, and when a colony gets crowded, winged individu- 

 als are produced that may spread the species to other plants. 

 They suck the juice from the tender parts and weaken or kill 

 the plants upon which they are allowed to thrive. One species 

 that frequents lettuce, peas, and other cultivated crops is known 

 as the green fly or green bug. Plant lice excrete a sweetish 

 fluid that is greatly relished by ants, and the latter may usu- 

 ally be found in attendance upon them. Ants also contribute 

 to the spread of the aphids by carrying some of them off to 

 new pastures when the colony on a given leaf becomes crowded. 

 The attendant ant of the corn-root louse actually carries the 

 aphids off to a safe place and cares for them 

 until the corn is up and then places them on 

 the roots of the young plants, where they 

 spend the rest of the summer. 



Squash bug. The squash bugs are large 

 angular insects found on the underside of the 

 leaves of squash, pumpkin, and the like. They F 



have an exceedingly disagreeable odor and ^ squash bug 

 are commonly known as " stinkbugs." The 

 egg masses are conspicuous as large, shining brown patches 

 and may be gathered by hand and burned. Kerosene emulsion 

 may be used as a spray for the mature insects. 



Mealybug. House plants and the specimens of the florist 

 often become infested with mealy bugs. These are small 

 fuzzy insects, white in color, that suck the juices from plants 

 and are hard to exterminate because ordinary sprays do not 

 harm them. No absolutely certain remedy seems to be known. 



Scale insects. In appearance scale insects are minute scale- 

 like objects clinging close to the bark of young trees of many 



