60 



SOME INSECTS INJURIOUS TO TRUCK CROPS. 



field and at the insectary at Washington, D. C, show that this 

 species is undoubtedly a continuous breeder, as in the case of the 

 variegated cutworm {Peridroma marcjaritosa Haw.), the larvse being 

 present in the field throughout the long summer season of the South. 

 Juh^ 30, by request of the county commissioner, Mr. H. H. Dick- 

 son, the junior author went to the County Home and found a sweet- 

 potato patch badly infested, thousands of larvae present, and the 

 leaves turning brown and drying out. Superintendent Harris stated 

 that an earlier brood did great damage to cowpeas, but this could 

 not be verified by specimens. In the sweet-potato field the larvae 

 started on the south side and, after stripping the first four or five 

 row^s, moved over to the next rows and eventually infested the entire 



Fii;. 10. — TIk' semitroiiical army worm (I'rodciiid criildiiin) : I'ield of late Irish potatoes 

 showing vines entirely stripped by larvoe ; Orlando, Fla., July 6, 1907. (Original.) 



field. A Mr. Porter, near the County Home, reported 5 acres 

 stripped in three days after the larva? were noticed at work, these 

 having started at one side of the field and swept it clean. The 

 larvae of a third generation were observed at Mr. Cheney's place at 

 this time; most of them, however, had already gone into the earth 

 to transform. 



August 3, adults that had pupated about July 25 began to emerge. 

 Thus the pupal period occupied about nine days. At this time a 

 number of young larvae were noted feeding upon amaranth, wild 

 Solanum, and castor-oil plants. ^Vlien disturbed they dropped and 

 hung by threads. 



