THE ALFALFA CATEEPILLAR. 



25 



scribed by him x as new. This is supposedly a new record of habit 

 for this species, but according to Mr. Wilson it was reared time and 

 again from pupse which were alive when collected; thus the flies 

 could not be acting as scavengers, but must have been true parasites. 



OTHER INSECT ENEMIES. 



Fig. 16. — Bollworm {Heliothis obsolete), an 

 enemy of the alfalfa caterpillar. Twice 

 natural size. (Author's illustration.) 



A large green caterpillar, known as the bollworm, Heliothis obso 

 leta Fab. (fig. 16), which can be 

 distinguished from the alfalfa 

 caterpillar because it is of a 

 lighter green color, about one- 

 fourth larger, hairy, and rough 

 in appearance rather than 

 smooth, with three black lines 

 traversing its body lengthwise, is quite prevalent in the Imperial 

 and Salt River Valleys, and is often mistaken for the alfalfa 

 caterpillar by many farmers. As observed by the writer,. and later 

 by Mr. T. Scott Wilson, it was found to do very little damage to al- 

 falfa, but to be a ravenous enemy of the alfalfa caterpillar, never eat- 

 ing alfalfa as long as it could find the larva? 

 or pupse of Eurymus. Messrs. E. O. Gr. Kelly 

 and T. H. Parks noted this species at Welling- 

 ton, Kans., in the summer of 1909, and re- 

 ported it as being of a predaceous habit. 2 



The writer observed a bollworm larva to 

 eat five large larvae of Eurymus during a 

 single day, and both the writer and Mr. T. 

 Scott Wilson counted dozens of pupal cases 

 with the contents eaten out (fig. IT) and 

 many times with the Heliothis larva still 

 feeding upon and devouring the pupse. Mr. 

 Wilson, on July 15, 1913, remarked in his 

 field notes that "Heliothis was observed in 

 fig. 17.— chrysalis of alfalfa p- rea t numbers feeding upon Eurvmus pupse, 



caterpillar that has been fe . *= r J ■, 



eaten out by a boiiworm. and m a few instances on Eurymus larvae. 

 Enlarged about two diam- The Heliothis makes a hole in the side of 



eters. (Original.) 



the pupa, through which he puts his head 

 and eats out the contents of the pupa." The writer has observed the 

 end of the abdomen eaten off the pupa ; again, an opening would be 

 made on the side, often the entire side being destroyed. 



1 Malloch, J. R. The insects of the dipterous family Phoridaa in the United States 

 National Museum. Proc. U. S. Nat. Mus., v. 43, p. 459-460, 1912. "AphiocJiwta perdita,. 

 new species," p. 459. 



2 This cannibalistic habit has also been observed in Texas by Quaintance and Brues. 

 (U. S. Dept. Agr., Bur. Ent, Bui. 50, p. 79-80, 1905.) 



