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NA TURE-STUD Y RE VIE W 



[6:6-Sept., 1010 



conceptions of the habits of insects and of 

 the injuries inflicted by them. Moreover, 

 by such personal studies the student can 

 get something- that is more important than 

 the particular facts that he learns, and 

 something that he gets too little of in the 

 schools, namely, the habit of trusting his 

 own senses and his own reason. 



The best part of the school year for the 

 study of insects is autumn. Among the 

 more important insect pests available for 

 study at that time are the following: 



Corn root-louse, Aphis maidiradicis. 



(Fig. 8.) A bluish green plant louse on the 

 roots of corn, attended by ants. The 

 aphids can be kept alive in the laboratory 

 on the roots of seedling corn, and their 

 eggs obtained. 



Northern corn root-worm, Diabrotica 

 longicornis. (Fig. 9). The injury by this 

 insect is common in old cornfields, but by 

 autumn the larvae have transformed to 

 small grass-green beetles, that are abund- 

 ant on the blossoms of thistle, sunflower, 

 clover, etc., and on the rinds of squashes. 



White grubs, several species of Lachnosterna. Larvae and 

 fresh beetles can be found by following the plow in early fall, or 

 by digging up injured corn plants or strawberry plants. 



Wireworms, Melanotus, etc. (Figs. 10,11.) The larvae 

 are common in the soil, and the adults also plentiful, many of the 

 species hibernating as beetles. 



Corn worm or cotton boll worm. Heliothis obsoleta- 

 The caterpillars, familiar objects on ears of sweet corn, 

 are common in autumn on ears of field corn, under the husks. 

 The larvae burrows and the pupae are not difficult to find in the 

 soil of a cornfield that has just been badly infested. 



Chinch bug, Blissus leucopterus. (Fig. 12.) This pest has 



FIG. 6. 



A— MOSQUITO LARVA; 

 B — PUPA 



