78 THE UNIVERSITY OF OKLAHOMA 



and Their Differentiation. Ann. Trop. Med. & Parasit., 

 9:109-162. 

 Wigdor, Meyer, 1918. A New Fluke from the Dog. Jour. Am. 

 Vet. Med. Assoc, 54:254-257. 



XII. EXPERTMENTS ON EGG PRODUCTION IN 



BRUCHUS 



Alfred Brauer 



From the Zoology Department, University of Oklahoma. 



Contribution No. 36, Second Series 



The following observations of Bruchus quadramaculatus were 

 made at the University of Oklahoma betwene June 1 and August 1, 

 1922. The work was preliminary to a study of the embryology of 

 the weevil and was primarily concerned in determining the optimum 

 temperature at vv^hich the v/eevils deposit their eggs. The humidity 

 in each experiment was kept at as near a point of saturation as 

 it was possible to do so. The weevils vised were from the stock 

 of Dr. J. K. Breitenbecher. 



In the first test twelve females were mated and placed into 

 test tubes with cowpeas. They were kept at a temperature of 

 37° C. saturated humidity. This test lasted over a period of five 

 days. The number of eggs layed by the weevils ranged Irora to 

 87. Thirty-eight was the average. Twenty-nine was the largest 

 number of eggs produced by a female in a twenty-four hour period. 

 This occuired tv^fice by the female which laid the 87 eggs. On 

 the fourth day of the test five of the females had died. On the 

 following day all of the remainder were dead. 



The day after this experiment was started, eight other pair 

 were mated in the same way. Here the average number of eggs 

 laid was 39, although three pair failed to produce any eggs. Ninety- 

 seven was the largest number laid by a female. 



An observation was made at this time on the distribution of 

 the eggs over the peas in the bottle. In most cases there was but 

 one egg on a pea. This also is true of the first lot. Only in two 

 or three cases were there mor© than two eggs on a pea, while 

 most frequently where Jess than twenty eggs were laid in one day 

 tliey wp''® ciisinbuted so that there was seldom more than on egg 

 'on a pea. 



On June 19 twenty-five matings were made and run at the same 

 'temperature. This was stock that had been in-bred for several 

 generations. Here the largest number produced by any female for 

 the entire time was 22. Seven had laid only one egg during the 

 entire period. These were active vigorous weevils. Part of them 



