34 J- T. PATTERSON. 



given credit for having first discovered long ago that certain 

 butterflies belonging to the genus Solenobia lay unfertilized eggs 

 which develop into normal imagines, and later von Siebold not 

 only confirmed this observation, but also discovered that Psyche 

 helix reproduced parthenogenetically. It has since been shown 

 by several workers that the silk moth, Bombyx mori, may under 

 certain conditions reproduce by parthenogenesis. 



III. PARASITES OF GNORIMOSCHEMA SALINARIS. 



Riley reports six hymenopterous parasites for Gnorimo schema 

 gallcesolidaginis , and in addition to these he found a beetle larva 

 and another lepidopterous larva which intrude as inquilines 

 within the cavity of the gall made by this species. At least five 

 hymenopterous parasites have been found associated with 

 G. salinaris. The most important of these is Copidosoma 

 gelechice, which is by far the most common parasite attacking 

 the moth. The other four species are CalUephialtes notanda 

 Cress, Epiurus sp., Eurytoma sp. (pupa), and Pseudacrias sex- 

 dentatus Girault. The first of these four occurs most frequently, 

 while the last has been observed but a few times. However, it 

 is of special interest, inasmuch as it is the only observed case of a 

 second parasite emerging along with Copidosoma, although the 

 larvae of other species have been found associated with the larvae 

 of Copidosoma. On September 3, 1914, six individuals, all 

 females, emerged together with a brood of about one hundred 

 Copidosomas from a single carcass. The small pupae of Pseu- 

 dacrias lying among those of Copidosoma were observed through 

 the transparent chitin of the carcass of the host some days prior 

 to their emergence. They were not grouped together but scat- 

 tered about in different parts of the carcass. Each pupa was 

 inclosed in a chamber very much smaller than, but exactly similar 

 to that containing a Copidosoma pupa. 



Usually Pseudacrias larvae do not pupate until after the larval 

 host has undergone this process. About a dozen Gnorimoschema 

 pupae have been found containing Pseudacrias pupae, which later 

 emerged. It is not probable that Pseudacrias is polyembryonic. 

 First, because both male and female individuals usually emerge 

 from the same pupal host; and second, because the individuals 



