SAC-BEARING LEPIDOPTERA. 33 



or rocks in their vicinity they creep high up on them, and spin 

 down the lower aperture of their dwelling firmly. In passing 

 through the process of moulting also, these caterpillars, like 

 all other Sac-bearers, always spin down their habitations tem- 

 porarily. The evolution of the moth takes place in the same 

 year*. If after some time we examine the spun-down sac of a 



* This Sac-bearer, like the other Psychida, is exposed to the attacks of 

 Ichneumonida. It is remarkable that the Ichneumonidous parasite of Psyche 

 Helix is a Chalcis, whilst I have never yet reared a Chalcis from the caterpillars 

 of the other Psychidce. This Chalcis, which was indicated to me by Kollar 

 under the name of Chalcis nigra, does not, however, appear to occur very gene- 

 rally. Reaumur obtained it from the sacs of Psyche Helix found in France, 

 as appears from his notice, short as it is (see Mem. pour serv. a I'Hist. des Ins. 

 torn. iii. p. 250); the sacs collected near Modling also furnished me with this 

 Chalcis in abundance ; but on the other hand, from more than a hundred sacs 

 which I had obtained from Tegernheim near Ratisbon, no Chalcis, and indeed 

 no Ichneumon at all, escaped. The Chalcis always eats its way out at the side 

 of the sac between the first and second whorls, and leaves a round hole corre- 

 sponding with its size on the outside of the sac (fig. 1 6). This Chalcis (figs. 

 13, 14) belongs, according to Nees von Esenbeck's Hymenopterorum Ichneu- 

 monibus ajfinium Monographic?, vol. ii. p. 27, to the species of the genus Chal- 

 cis described in Sectio II. (abdominis petiolo brevissimo) ; its specific character 

 may be diagnosed in the following manner : nigra, pubescens, scutello in me- 

 dio marginis dente obtuso, femoribus posticis subtus obsolete unidentatis, tar- 

 sis piceis. Long. lin. 1 1. The other Ichneumons reared by me from the 

 caterpillars of PsychidcB are as follow : 



Campoplex difformis, Gr., from Fumea nitidella, Ochs. 

 - Iretus, Rtzb., from Fumea betulina, Zell. 



lugens, Rtzb., from Fumea nitidella and betulina. 



psilopterus, Gr., from Solenobia lichenella, Linn. 



Cryptus eborinus, Rtzb., from Fumea nitidella. 



spiralis, Gr., from Talasporia pseudobombycella, Ochs. 

 Hemiteles albipennis, Rtzb., from Solenobia triquetrella, Fisch. v. R. 



areator, Gr., from Psyche calvella, Ochs. and Fumea nitidella. 



elongatus, Rtzb., from Talaeporia pseudobombycella. 



gastrocoelus, Rtzb., from Solenobia triquetrella and lichenella. 



imbecillus, Gr., from Fumea nitidella. 



leucomerus, Rtzb., from Solenobia triquetrella, Fisch. v. R. 



melanarius, Gr., from Solenobia triquetrella. 



similis, Gr., from Psyche calvella. 



tristator, Gr., from Fumea nitidella. 



1 nov. sp. from Fumea betulina. 



2 nov. sp. from Talaeporia pseudobombycella. 



Microgaster longicauda, Wesm., from Solenobia lichenella. 

 Pezomachus agilis, Gr., from Psyche calvella. [Pezomachus 



D 



