466 Phylum Arthropoda 



Chapman, R. N. 1918. The confused flour beetle {Tribolium confusum Duval). 



Minn. State Ent. Rept. 17:73. 



— : 1928. Quantitative analysis of environmental factors. Ecol. 9:111. 



Chapman, R. N., and Baird, Lillian. 1933. The biotic constants of Tribolium 



confusum Duval. J. Exper. Zool. 68:293. 

 Good, Newell E. 1933. Biology of the flour beetles, Tribolium confusum Duv. 



and T. ferrugineum Fab. /. Agric. Res. 46:327. 

 Park, Thomas. 1934. Observations on the general biology of the flour beetle, 



Tribolium confusum. Quart. Rev. Biol. 9:36. 

 1934a. Studies in population physiology III. The effect of conditioned 



flour upon the productivity and population decline of Tribolium confusum. 



J. Exper. Zool. 68:167. 



1935. Studies in population physiology IV. Some physiological effects 



of conditioned flour upon Tribolium confusum Duval and its populations. 

 Physiol. Zool. 8:91. 

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A METHOD OF OBSERVING THE DEVELOPMENT OF 

 TRIBOLIUM CONFUSUM 



Herbert S. Hurlbut, Cornell University 



EGG LAYING may be observed by using a paraffin oviposition tray 

 prepared with a double row of cells on a piece of glass (6 inches 

 long by 3 inches wide is a convenient size). 



Cover one side with paraffin about % inch thick, save for a longi- 

 tudinal strip % inch wide on one edge. In the paraffin two longitudinal, 

 parallel rows of cells are made, by rotating on it with pressure the 

 warmed mouth of a 6 drachm homeopathic vial. The cells should then 

 be excavated down to the glass. Cover the cells with individual squares 

 of ordinary glass. To close a cell, warm a square of glass and press it 

 down with forceps. 



Use only one row of cells at a time, changing each day. Number each 

 pair of cells on the bare glass at the side. Prepare the cells for the 

 beetles by dusting very lightly with the food material. Whole wheat 

 flour or whole milk powder may be used. After two beetles (a pair) 

 have been in a cell for a day, remove them to the opposite cell and ex- 

 amine the cell they have occupied for eggs. The eggs may be identified 

 by their ovoid shape and yellowish color. They may be removed with 

 a needle, the end of which has been ground flat and bent at an angle of a 

 little less than 90 degrees. 



The larvae may be reared in petri dishes dusted with the food ma- 

 terial. Dust very lightly at first, so that the small larvae may not be 

 hidden. Neither larvae nor adults will escape from uncovered dishes 

 if the sides are clean. 



Reference 



For the culture of Tribolium ferrugineum and mealworms see p. 242. 



