294 Phylum Ar thro poda 



The extraordinary and diagram-like color patterns, the good size of 

 their chromosomes and, perhaps, a few other features justify the extreme 

 effort necessary in breeding the grouse locusts for genetics studies. I 

 believe that it would be easier and more economical to breed 100,000,000 

 Drosophila than 1,000,000 of these Orthoptera. 



As already stated they eat mainly algae. In a humid climate, and 

 where they are available, the scrapings from the pots in greenhouses 

 serve very well. In the climate of Manhattan, Kansas, the filamentous 

 algae only are available, Hydro diet yon sp. being the most satisfactory. 

 Much difficulty is exerienced from the invasion of black or blue-green 

 algae, fungi, and masses of decayed algae, and the acidity and other 

 chemical conditions of the soil which render it unavailable. 



It has been ascertained that an extra, winter generation of the Man- 

 hattan, Kansas. Acrydium arenosum may be secured by exposing parents 

 and then the offspring to continuous lights, either the ordinary white 

 light from Mazda bulbs or mercury vapor radiation through ordinary 

 glass, the latter being somewhat more effective (Sabrosky, Larson, and 

 Nabours, 1933). It is believed that these insects offer very fine op- 

 portunity for irradiation work of various sorts. 



The females of P. texanus, A. eurycephalus, and others reproduce 

 also parthenogenetically, the unfertilized eggs, with rare exception, pro- 

 ducing females. The females are generally about three times as pro- 

 lific when mated as when unmated. A mated female may have part of 

 her ova fertilized, and also produce from unfertilized ova, by partheno- 

 genesis, an additional number of offspring which are nearly always 

 females. 



Bibliography 



Hancock, J. L. 1902. The Tettigidae of North America 



Nabours, R. K. 1925. The grouse locust Apotettix eurycephalus. Kan. Tech. 



Bull. 17. 



1929. The genetics of the Tettigidae. Bibliographia Genetica 5:27. 



Nabours, R. K., and Robertson, W.R.B. 1933. An X-ray induced translocation in 



Apotettix eurycephalus, Hancock (Grouse Locusts). Proc. Nat. Acad. Sci. 19:234. 

 Robertson, W. R. B. 1935. Demonstration of effects of X-rays on male germ 



cells in Apotettix eurycephalus; Amer. Nat. 69: 

 Sabrosky, Larson, and Nabours. 1933. Experiments with light upon reproduction, 



growth, and diapause in grouse locusts (Acrididae, Tetriginae) ; Trans. Kan. 



Acad. Sci. Vol. 36. 



