FURTHER BIOLOGICAL NOTES ON THE COLORADO 



POTATO BEETLE, LEPTINOTARSA 10-LINEATA* (SAY), 



INCLUDING OBSERVATIONS ON THE NUMBER OF 



GENERATIONS AND LENGTH OF THE PERIOD 



OF OVIPOSITION. II, ILLINOIS. 



By A. A. Girault and James Zetek, 

 Office of the Stat'- Entomologist of Illinois. 



In presenting for publication the results of a third successive 

 year's observations on the biology of this insect made in the 

 latitude of Urbana, Illinois and supplementing those made in 

 Georgia in 1906 (Girault and Rosenfeld, 1907) and in Ohio in 

 1907 (Girault, 1908), it becomes necessary to state that little 

 or no progress has been made in regard to the continuity of 

 observation and experiment, so that they should still be classed 

 as desultory. The observations were made in the open or 

 east insectary of this office at Urbana under as normal conditions 

 as possible, but during odd hours and without previous fore- 

 thought or planning and subject to much neglect at a critical 

 time toward the last. 



They are presented, therefore, mainly to add to the sum of 

 biological data on this insect, which in the end may lead to the 

 discovery of important laws. At present, however, they form 

 but a small beginning and cover but one or two biological fac- 

 tors; as they supplement to a large degree the observations made 

 in Ohio (Girault, 1908), they are presented in the same general 

 manner. 



Those who gather data of this kind cannot help being 

 impressed by our poverty in this respect and by the urgent 

 necessity of accuracy in observation, to the minute as regards 

 time and to the fraction of a degree as regards temperature, 

 though it is true that such errors as occur should be chance 

 errors, hence negligible. And most decidedly other factors 

 should be taken into consideration, for in matters of this kind, 



* This may seem a trivial matter but consistency demands that the specific 

 name of this insect be written as it was originally by Say; I see no necessity for 

 change or reason therefor and certainly stability in nomenclature is not aided by 

 making one. See articles 15 and 19, The International Code of Zoological Nom- 

 enclature as Applied to Medicine (Stiles, 1905). If a change was necessary the 

 form x-lineata would seem preferable to the other, being less radical. A. A. G. 



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