222 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 7 



tions may start from either end of the body and move to the other end. 

 There are about three contractions starting from the anterior end to 

 two from the posterior end and there are about two contractions per 

 minute. 



The Adult Parasite 



Emergence — In emerging the parasite cuts a zigzag opening, by 

 rasping and tearing with the mandibles, around three fourths of the 

 anterior end of the egg. Then by pushing with the abdomen and legs 

 the cap is pushed back with the head. The head is thus forced out 

 and the parasite feels around with its antennae. Then by continually 

 working the legs within the shell and by extending its abdomen back 

 to the posterior end of the shell it finally gets the front legs free. Then 

 by pulling with the front legs and pushing as before it gradually works 

 the rest of the body free from the shell. The time of day when emer- 

 gence occurs varies with the temperature. During the spring when the 

 temperature at night fell below 50° or 60° F., the emergence occurred 

 between 9.00 a. m. and 9.00 p. m. From June 2 until September 8 

 when the temperature at night was above 55° or 60° F. the emergence 

 occurred for the most part between 9.00 p. m. and 9.00 a. m. From 

 September 8 on with temperature conditions the same as in the spring 

 the emergence occurred during the day. 



Relation and Economy of Sexes — In a number of experiments 

 conducted to determine the relation and economy of sexes it was found 

 that where a male is supplied to each female a higher percentage of 

 parasitism was obtained. It was also found that a greater number of 

 parasites reached maturity under these conditions. Table I gives 

 the results of these experiments : 



TABLE I.— SHOWING THE RELATION AND ECONOMY OF THE SEXES 



Number of Eggs — It was not possible to determine with any degree 

 of accuracy the number of eggs a female could deposit. Nineteen 

 individual females parasitized an average of 6.2 eggs; seventy-six 

 females of the first generation parasitized an average of 4.1 eggs; 

 sixty-three females of the second generation parasitized an average 



