176 



Elementary Principles of Agriculture 



been seriously damaged by the green bug. In other 

 parts, the entire grain crops have been almost destroyed 

 several times because the cool weather retarded the 

 multiplication of the parasites. 



Ichneumon flies are parasitized by other ichneumon 

 flies, and these in turn by others, reminding one of the 

 old adage that "Large fleas have smaller fleas to bite 



'em." 



246. Ants. Many 

 species of ants live on 

 the eggs and larvae of 

 other insects. They 

 are very useful in cot- 

 ton fields because they 

 destroy many boll- 

 weevils. The common 

 red stinging ant lives 

 on weed seeds and wild 

 grain. 



247. Lady Bugs are 

 another class of insect- 

 eating insects. They 

 feed on eggs of the 



* Colorado potato bugs, 

 chinch bugs, and plant- 

 lice. They are easily 

 recognized by their red 

 and black-spotted color. There are two kinds of lady 

 bugs found in the Southwest. One species, Megilla 

 maculata (Fig. 114), is especially active in feeding on 

 the green bug on grains, while another, Hippodamia 

 convergens, is more active on the plant-lice on cotton 

 and melons. The latter will lay about fifteen eggs per 



Fig. 114. Two common species of lady bugs, 

 a, hippodamia; 6. megilla; c and d, larva 

 stages. After Chittenden, United States 

 Department of Agriculture. 



