Rail — The Biology of Stagmomantis Carolina. 9 



The accompanying table shows the number of insects 

 that hatched each day from each of the 39 egg-cases. It 

 will be seen that in just about one-half of them practi- 

 cally all of the occupants emerged at one time, with only 

 a few stragglers, and that in the remainder the emerg- 

 ence continued through two or three mornings. The 

 mean as well as the mode of emergence falls practically 

 upon June 10. 



A number of egg-cases were partially or entirely par- 

 asitized by Podagrion mantis. In some cases these 

 parasites emerged before and sometimes after the usual 

 time for the emergence of the host. They do not leave 

 by the openings provided, but bore their own exits in the 

 top and sides of the case. These holes are to be clearly 

 seen in Y, Z, BB and NN in PI. XV. Not a great deal is 

 known of the life history of this Chalcid. The eggs are 

 deposited in the egg-case in the fall and the adults 

 emerge during the following May and June; just how 

 the parasites spend their life from this time until the 

 following September or October when the ootheca are 

 again deposited and hosts supplied would be an inter- 

 esting discovery. The fact that they are mature at 

 emergence would lead one to conclude that they should 

 be ready at once for mating and oviposition. 



A few were infested by the larvae of Anthrenus (sp?). 

 Whether these beetle larvae feed upon the ootheca as well 

 as on the living eggs is not known, but at any event they 

 injure the egg-case sufficiently to destroy the develop- 

 ing embryos. 



Four egg-cases, while apparently not parasitized, gave 

 forth only 5, 1, 1 and 5 insects respectively. Five others 

 of apparently similar condition produced no young 

 whatever. I suspected that these latter ones contained 

 infertile eggs, and later in the season discovered that 

 unfertilized females construct normal egg-cases. 



Our table shows the greatest number to hatch from 

 any one egg-case to be 140 and the minimum in seven 



