304 JOURNAL OF ECONOMIC ENTOMOLOGY [VoL 1 



pact, she would deposit them in shallow cre\'ices, or even right on the 

 surface. The female certainly shows a preference for a crack or 

 crevice as a place to deposit her eggs. She oviposits in the soil any- 

 where Avithin a radius of five or six inches of the stem of the young 

 plant. Although the eggs are frequently laid between the plant stem 

 and the surrounding earth, we have found no evidence to show that 

 this is a favorite place. In instances where oviposition was observed, 

 and this happened to be on damp soil, she simply brought the tip of 

 her abdomen down nearly or quite to the surface of the ground, and 

 pushed the eggs out, or. finding a furrow, she crawled into it and 

 deposited eggs on the sides and bottom. 



Experiment has shown that while the eggs are generally deposited 

 on moist soil, they can withstand some desiccation if again returned 

 to moist conditions, but that they never hatch if kept continuously in 

 a dry situation. 



A dissection of 18 gravid females collected at different times from 

 late June to September showed an average of only 33 well-developed 

 eggs per individual, with the upper extreme as 59. Yet in the breed- 

 ing-cages, five females produced an average of 88 eggs each, with 54 

 and 117 as extremes. The cage records indicate that, once the beetle 

 begins to oviposit, she continues at frequent intervals until her supply 

 of eggs is exhausted. 



Careful records of 32 eggs show that an average of 8.75 days is 

 required under an average mean temperature^ of 74° F. with an 

 accumulation of 653.8° F. (read) or 651.03° F. (measured) to bring 

 them from deposition to hatching. 



Inasmiich as recent studies point to the fact that each insect has 

 a different critical temperature, no effort has been made to compute 

 the effective temperature, but the amount given represents all the 

 degrees above 0° F. 



iThe average mean temperature has been computed by (1) averaging the 

 mean temperature of the days through which eacli egg passed before hatch- 

 ing, and then (2) averaging the average mean temperature of all the eggs. 

 The mean temperatures of the days through which each egg passed were 

 summed for each egg, and the average sum of the temperatures for all the 

 eggs was taken as the sum temperature of the egg stage. Finding that the 

 daily mean derived by measuring the irregular polygon made by the thermo- 

 graph pen on the revolving record-sheet showed less variation, and hence was 

 likely to be freer from the variation to which any such instrument is likely 

 to be subject, I have given it as the measured sum, and also to conform to 

 common practice, the sum derived in the usual way has been given as the 

 read sum. In case the average means were practically the same, only one 

 has been given, but when both axe given, they are distinguished by the same 

 method as that used in distinguishing the sum temperatures. 



