70 



INSECTS INJURIOUS TO THE APPLE. 



FIG. 03. 



brought to the ground and destroyed. Fall ploughing has 

 been recommended to destroy the chrysalids by turning them 

 up, when they are likely to be either killed by exposure or 

 devoured by birds. Hogs also are very useful in destroying 

 this pest by rooting up the chrysalids and eating them. 



These insects have many natural enemies. A small mite, 

 Nothrus ovivorus Packard (Fig. 63), destroys the eggs? A 

 minute parasitic fly deposits her eggs 

 within the eggs of the canker-worm and 

 destroys them. In the larval state they 

 are preyed on by a small four-winged 

 fly, a species of Microgaster, which, after 

 having fed upon its victim to full growth, 

 eats its way out, and constructs a small 

 oval white cocoon attached to the body 

 of the caterpillar. A species of Tachina, 

 a two-winged fly similar to Fig. 46, No. 

 21, is also a parasite on these worms. Predaceous insects 

 also feed upon them, especially the Green Caterpillar-hunter 

 (Fig. 47), the Copper-spotted Calosoma (Fig. 48), and the 

 Rapacious Soldier-bug, Sinea diadema (Say) (Fig. 64). The 



Fraternal Potter-wasp, Eumenes fraternus Say (a, Fig. 65), 

 stores the cells for her young with canker-worms, often placing 

 as many as fifteen or twenty in a single cell. In the figure, at 



