418 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 7 



temperature changes upon the oviposition of the beetles, a series of 

 experiments was begun to compare the variation in mean daily tem- 

 perature throughout the oviposition period of the weevils, with the 

 rate of oviposition of the beetles kept in confinement. An opportunity 

 was also afforded to obtain accurate information upon the average 

 number of eggs deposited by each female during the season. 



The life history of the alfalfa weevil has been thoroughly worked 

 out in Utah by Dr. E. G. Titus of the Utah Agricultural College and 

 Experiment Station, and by agents of the United States Bureau of 

 Entomology. A full account of this work can be found in Bulletin 

 No. 110 of the Utah Agricultural College and Experiment Station, and 

 No. 112 of the Bureau of Entomology, United States Department of 

 Agriculture. 



The beetles commence depositing eggs the first warm days of spring. 

 The oval, lemon-yellow eggs are placed in clusters inside the alfalfa 

 stems, through punctures in the stem made by the beak or snout of 

 the beetle. They are placed in a row, being crowded both above and 

 below the puncture, the last one often filling up the puncture made by 

 the beetle. From two to thirty may be placed in one mass, though six 

 to eighteen is the usual number. From one to four minutes elapses 

 between the passage of each egg through the ovipositor and in each 

 case the preceding egg is crowded up or down the alfalfa stem giving 

 a symmetrical arrangement to the group (pi. 12, fig. 2). In early spring 

 many eggs are deposited in punctures made in dead stems of the pre- 

 vious season's growth and which are lying on the ground where the 

 beetles first crawl about. Later, a few are placed in green weeds and 

 grass stems in alfalfa fields. By far the greater number are deposited 

 in the green alfalfa stems, and these were used in the temperature 

 experiments exclusively, the plants being grown under cover and care 

 taken to have them free from infestation. 



The beetles used in the experiments in 1912 were collected March 

 26 from alfalfa fields where they hibernated, and were placed out of 

 doors in small cylinder cages kept in the shade, and kept outside from 

 the time the beetles were taken from hibernation until they ceased 

 ovipositing and died. A male and a female were placed in each cage, 

 and fresh sprigs of alfalfa introduced frequently, and upon which they 

 fed and in the stems of which they deposited their eggs. The eggs 

 were counted daily, or every second day as the opportunity afforded, 

 and fresh alfalfa added. Sixteen pairs of beetles were used through- 

 out the spring and summer, individuals being replaced when they died 

 by other over-wintering beetles kept in reserve, so that the average 

 daily oviposition record remained unbroken. The beetles began depos- 

 iting eggs March 26 and continued until August 10, as shown by the 



