128 



APPLIED ENTOMOLOGY 



Destroying the descending larvae and the pupse on the lower part of the trunk 

 and on the ground, with a strong kerosene emulsion spray is an auxiliary treat- 

 ment, but as these individuals have completed their feeding, this affects only the 

 abundance of the next generation. Power sprayers are a necessity for spraying 

 tall trees in the way here described. 



The Tortoise Beetles are interesting members of the Chrysomelidse 

 (Fig. 119) because of their resemblance in form to tortoises and inmost 

 cases, on account of their golden color, which is 

 lost after death. Some species attack the sweet 

 potato but are not usually serious pests. They are 

 small insects, usually not over a quarter of an inch 

 long, nearly as wide, and often with black mark- 

 ings. If they become injuriously abundant, spray- 

 ing the leaves on which the larvae feed, with arsenate 

 of lead will control them. 



Family Bruchidae (Pea and Bean Weevils). In 



FIG. 119. Tortoise . .. . . 



Beetle (Deioyala davata this group of small beetles the head is extended 

 Fab.) about 2^ times downward into a broad but short snout. The 



natural size. (Original.) ,1111 ,, , - i 



elytra are snorter than the body leaving the hinder 



end of the abdomen exposed above. The larvae feed in the seeds of 

 leguminous plants such as peas and beans, and frequently cause a great 

 amount of damage. Several kinds are abundant in the United States, 

 the pea weevil and the common bean weevil being perhaps the most 

 important. 



The Pea Weevil (Bruchus pisorum L.) . This pest of field and garden 

 peas winters as the adult beetle (Fig. 120a) either in peas or in protected 

 places, and after the pea pods 

 begin to form, lays its eggs on 

 them. It is about one-fifth of 

 an inch long, brownish, with 

 black and white spots. The 

 larvae (Fig. 1206) bore their way 

 into the peas, the holes they 

 make either closing up or being 

 too small to be noticed, and feed 

 on the contents of the pea until 

 full-grown. They then pupate 

 (Fig. 120c) and upon the pro- 

 duction of the adult, those in the South leave the peas, while in the 

 North they remain in them over winter. Only one weevil usually feeds 

 in a pea and the insect cannot reproduce in dried peas. There is there- 

 fore only one generation a year except where spring and fall crops of peas 

 are grown. 



FIG. 120. Pea Weevil (Bruchus pisorum L.) : 

 a, adult beetle; b, larva (grub); c, pupa. 

 Greatly enlarged. (From U. S. D. A. Farm. 

 Bull. 983.) 



