ICHNEUMONID FINAL INSTAR LARVAE — SHORT 421 



Tribe Thymaridini (=Eclylini) 



Figure 12a, b 



Members of this tribe are parasitic mostly on small Lepidoptera. 

 Eclytus omatus Holmgren is a parasite of Tenthredinidae. 



The species examined were E. omatus Holmgren (CD A) (fig. 12a), 

 E. pleuralis (Provancher) (CD A), Hyhophanes scahriculus (Grav- 

 enhorst) (GCV) (fig. 12b), and Neliopisthus elegans (Ruthe) (GCV). 



All the head sclerites are present with the exception of the prelabial 

 and the dorsal part of the labral sclerite is absent in Hyhophanes and 

 Neliopisthus; the epistomu is slender in Eclytus but relatively broad, 

 although lightly sclerotized, in Hyhophanes and Neliopisthus; the lat- 

 eral parts of the labial sclerite meet the ventral almost at riglit angles 

 in Eclytus but the ventral part of this sclerite is rounded in Hyhophanes 

 and Neliopisthus; in Hyhophanes and Eclytus omatus each maxillary 

 and labial palp has three sensilla, one large, one small and one minute, 

 but in E. pleuralis each palp has two sensilla, one round and one cres- 

 centic; the mandible has a prominent row of teeth on the dorsal sur- 

 face of the blade; the closing apparatus of the spiracle is small and 

 the length of trachea which separates it from the atrium is twice as 

 long as the closing apparatus in Eclytus and three times as long in 

 Hyhophanes and Neliopisthus; the setae on the skin are prominent, 

 especially in Hyhophanes and Neliopisthus, and there are small spines. 



Eclytus fontinalis Holmgren is figured by Beirne (1941). 



Larval Key 



1. Setae on skin of thorax equal in length to blade of mandible .... Eclytus 

 Setae on skin of thorax as long as or longer than hypostonria 2 



2. Epistoma sharply arched Hyhophanes 



Epistoma not sharply arched Neliopisthus 



Tribe Idiogrammatini 



Figure 12c 



Idiogramma sp. was examined. The species of this genus are 

 parasitic on the larvae of Xyela feeding in the staminate cones of 

 Pinus. Idiogramma is an isolated genus showing no close resem- 

 blance to other Tryphoninae. 



The dorsal part of the epistoma is unsclerotized ; the pleurostoma 

 is very lightly sclerotized; the hypostoma, hypostomal spur, stipital 

 sclerite and labial sclerite are moderately sclerotized; each maxillary 

 and labial palp has two sensilla; there is no prelabial sclerite; the silk 

 press is very lightly sclerotized; a labral sclerite is present; the man- 

 dibles are distinctive in shape, each having a somewhat square base 

 and a curved toothless blade; the antenna has a large central sensillum 



