193 



make use of* the bag paper, nor have all individuals of rubiginosus 

 learned the labor-saving trick, as I repeatedly saw them during the 

 summer still gathering fibers of wood from fence posts and boards after 

 their time-honored fashion. 



THE METHODS OF PUPATION AMONG THE CHALCIDIDiE. 



By L. O. HowAKD. 



As a rule Chalcidid larvae which are internal feeders on their hosts 

 transform internally into naked, more or less coarctate pupae. 



With certain Encyrtin*, for one of which Dr. Riley has proposed the 

 excellent descriptive name of the '■'■ inflating chalcis-liy," particularly of 

 the genus Copidosoma, but also of Bothriothorax, Homalotylus, and per- 



ha])s others, the larva? inhabiting i , 



the host insect in great numbers, 

 when about to i)upate, cause a 

 marked inflation in the host larva 

 by the formation of oval cells 

 around the i)arasite. This inflation „ ,^ , „-..^, ,, ^. , . , , , 



' IMG. 16. — Larva of Litnocolletis, which has been in 



and the pupal cells which cause it fested by Copidosoma, enlarged (original). 



are very noticeable in thin-skinned host larvae. With a small larva like 

 that of Lithocolletis the ai)]xnirance of a string of dipterous puparia is 

 produced, as shown in Pig. 10. The nature of this cocoonlike cell and 

 the method by which it is produced are unknown. Its structure shows 



it not to be silk, nor yet 

 the last larval skin of the 

 parasite, and whether it 

 is an adventitious tissue 

 of the host larva or a 

 secretion of the jiarasite 

 or is explicable upon other 

 grounds I can not say. 

 It is a point for some ex- 

 ])ert histologist to decide 

 with fresh material, which 

 is not at hand at ]>reseut. 

 An exami)le of one of the inflating parasites in a thick-skinned host 

 larva is shown in Fig. 17. It is a Coccinellid larva infested with Homa 

 lotylus obseio-us m. The outlines of the parasitic cells are not so evident 

 as in the previous figure, but the host larva is very distorted and evi- 

 dently contains these cells. 

 Species parasitic upon endophytous larvae, and therefore feeding 



Fig. 



17. — Coccinellid larva infested by Homalotyltis ohscunis. 

 enlarge<l (original). 



