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JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 3 



or two of which have been plotted by Bachmetjew (2a). Thus the 

 rate of pulsation of the heart of the silk worm has been given by 

 Tichomirow (26) figure 15, and the food eaten by the larvge of Den- 

 drolimus pini by Regener (21), figure 16, all indicating the same gen- 

 eral relation of temperature to insect activity. 



10° c. 



20° c. 



10° C. 



20° C. 



10° c. 



20° c. 



Days 



Fig. 14. Relation of temperature to different stages of Toiuicns typographus 

 Linn; solid line represents 55 per cent and dash line 96 per cent moisture; 

 as given by Hennings (1907), original. 



Recent records of some of our own workers have also given data from 

 which we have been able to plot curves which are approximately cor- 

 rect, though the diverse conditions and lack of exact temperature 

 records, make them only approximate. Thus we have taken the 

 weather records for Paris, Texas, for 1904 and have determined the 

 average temperatures for the egg. larva and pupa stages of the Boll 

 Worm as given by Quaintance and Brues, which are shown in figures 

 17 and 18. The excellent work of Jenne upon the life history of the 

 Codling INIoth in Arkansas has given us the best data concerning the 

 egg stage of that insect, which we have plotted in figure 19.^ 



^ Unfortunately no temperature records are available for Siloam Springs, 

 Ark., where the work was done, but we have used the weather records of 

 Fayetteville, which is but twenty-five miles east and has practically the same 

 climate, so that the average temperature would be almost identical. 



