504 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ii» 



The following are figured in the literature: Trichomma enecator 

 (Rossi) (Rosenberg, 1934), Aphanistes armatus (Wesmael) (Beirne, 

 1941), Blaptocampus nigricornis (Wesmael) (Beirne, 1941). 



Tribe Therionini 



Figure 63 

 Larval Key 



1. Ventral part of labial sclerite lightly sclerotized Heteropelma 



Ventral part of labial sclerite not sclerotized Therion 



The following have been examined: Therion morio (Fabricius), 

 T. circumflexum (Linnaeus) (fig. 63a) , Heteropelma fulvicorne Townes 

 (fig. 63b). Therion morio (Fabricius) is figured by Cushman (1947). 



Interrelationships between the Subfamilies 



Although in many cases the larval characters suggest interrelation- 

 ships which are very similar to those which are believed to be shown 

 by the characters of the adults, there are certain discrepancies. 



Some similar adults, such as the Pimplini and Ephialtini, have very 

 different larvae. These differences may be correlated with the fact 

 that the larvae of the Pimplini are endoparasitic while those of the 

 Ephialtini are ectoparasitic. The larval characters of the Ephialtini 

 and similar tribes of the Pimplinae resemble those of other ectopara- 

 sites such as the Tryphoninae and Cryptinae rather than the Pimplini. 



There are certain structural features which appear to be connected 

 with whether the larva is an ectoparasite or an endoparasite. The 

 antenna in most ectoparasites is papilliform. In most endoparasites 

 it is reduced and disc-like. The mandible is toothed in most ecto- 

 parasites where teeth are necessary for holding on to the host and 

 for piercing the host skin. In most endoparasites the mandible is 

 without teeth. The labral sclerite is present in most ectoparasites 

 and absent in most endoparasites. The epistoma and the labral 

 sclerite are rarely present together, except in the Tryphoninae, where 

 the epistoma is slender. It is difficult to suggest a reason for this. 

 The anterior retractor muscles of the labrum insert on the median 

 part of the labral sclerite (Short, 1952, p. 39, fig. 7b). It is not 

 likely that the labral sclerite could brace the cranium in any way as 

 a substitute for the epistoma. The epistoma is well developed in 

 larvae with powerful mandibles. 



The closing apparatus of the spiracle adjoins the atrium in most 

 endoparasites, whereas in ectoparasites it may adjoin the atrium or be 

 situated some distance from the atrium. There is no obvious explana- 

 tion for this. It is generally assumed that the spiracles are open in 

 endoparasites in the final instar larva, which is carnivorous, feeding on 



