December, '14] TOWER. LIFE HISTORY OF PROSPALTELLA 427 



tion of large numbers of parasitized scales indicates that the broods of 

 the parasite coincide with those of the scale. 



It has not been possible to work out the length of the egg and first 

 larval stage, as while this work was in progress young scales were not 

 available for experimentation; however, it was possible to work out 

 the other stages, and these subtracted from the total leave an average 

 of from fourteen to nineteen days for the egg and first larval stages 

 combined. Again according to Marlatt the female scale molts for 

 the second time on the average eighteen days from birth and observa- 

 tions made on non-parasitized and parasitized scales show that the 

 majority of the first stage parasite larvae molt at approximately the 

 same time that the non-parasitized scales molt the second time. 



The length of the second larval stage averages from six to eight 

 days. 



The waste passing period, which terminates the growth of the second 

 larval stage and ends arbitrarily with the pigmentation of the antennae, 

 averages from one to two days. 



The pupal stage averages from eleven to twelve days. Internal 

 pupal development commences during the waste passing period. 



Copulation 



Sexual reproduction seems to be the rule as copulation has been 

 observed to take place in hundreds of cases among insects that emerged 

 both in the spring and fall. The percentage of males to females seems 

 to be about equal, as of 463 insects selected at random as thej^ emerged, 

 235 were males and 228 were females. 



Copulation was found to take place as soon as the parasites had 

 dried off after emergence and no doubt oviposition commences at 

 once, for as stated earlier females previous to emergence contain 

 developed eggs. 



Males and females crawling about do not seem to locate each other 

 from a distance by any apparent sense but more by accidentally com- 

 ing very close or in actual contact. In such cases the male either 

 pays no particular attention to the female or mounts her and is then 

 either driven off or copulation takes place. 



In copulation the male stands on the head and thorax of the female 

 and rapidly pats and rubs her antennae with his own and endeavors 

 to draw the antennae of the female to an erect position. The female 

 may resist the male and drive him away; even in cases where copula- 

 tion takes place the female usually resists at first, but occasionally 

 not at all. When the antennae of the female are raised to an erect 

 position by the efforts of the male, assisted by the female, they are 

 held behind and beneath those of the male and their tips are in con- 



