230 ~ JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



this date the material was moved to Clarksville, Tenn., where the tem- 

 perature was very much lower than at Tampa. At the present writing, 

 December 27, the remaining larvse in the exposed and check lots are 

 perfectly normal in appearance and are feeding. 



On November 2, nine of the exposed pupse had become adult, 

 one was crushed during an examination. By November 8, five of 

 the check pupse had become adult, the other five had died. December 

 27, eggs deposited by adults developing from exposed pupse have 

 hatched. 



It is evident from the above experiments that neither the "hard" 

 nor the ''soft" rays used gave any indications of affecting any of the 

 stages of Lasioderma. 



X-rays are known to have a very decided injurious effect upon 

 certain tissues and functions of the higher animals, and it seems 

 strange that this effect should not be noticeable upon insects. Since 

 there are other rays, little understood and little studied — said to be 

 associated with the hard and soft rays, the question naturally arises, 

 would any of these, if properly isolated, produce any effect upon 

 insects. 



SOME NOTES ON LAPHYGMA FRUGIPERDA S. AND A. IN 



PORTO RICOi 



By Thomas H. Jones, Assistant Entomologist, Experiment Station, Porto Rico Sugar 

 Producers' Association, Rio Piedras, P. R. 



The so-called "southern grass worm" or "fall army worm," the 

 local Spanish equivalent of which is "el gusano de yerba," is a pest of 

 considerable importance in Porto Rico. Because of this, and because 

 any data concerning this insect will be of timely interest, on account 

 of its unusual abundance in the eastern United States during the past 

 season, the following article has been prepared. This account deals 

 with its occurrence, life history, and enemies in Porto Rico, and in- 

 cludes a short note on an experiment with poisoned bait. There is 

 also appended a brief statement regarding another Noctuid, Remigia 

 rejmnda Fab., since, because the larvse of this species are sometimes 

 found accompanying those of Laphygma frugiperda, it has been nec- 

 essary, in this article, to include more or less data concerning its 

 occurrence. 



This paper is a summary of the field and breeding notes on La- 



1 Published by permission of Mr. J. T. Crawley, Director of the Experiment Station 

 of the Porto Rico Sugar Producers' Association. 



