ICHNEUMONID FINAL INSTAR LARVAE SHORT 401 



5. Ventral part of labial sclerite broad and without lobes on ventral surface. 



Theroniini 

 Ventral part of labial sclerite, if broad, has lobes on ventral surface ... 6 



6. Mandible triangular with no sharp differentiation between base and blade. 



Xoridini 

 Mandible with sharp differentiation between base and blade . . EphiaJiini 



Tribe Ephialtini 



Figures 2-4 



The epistoma is absent except in Tromatohia where it is present as 

 a thin, hghtly sclerotized arch; the pleurostoma is lightly sclerotized; 

 the hypostoma is well sclerotized and may be enlarged posterior to 

 the hypostomal spur; the spur of the hypostoma meets the stipital 

 sclerite at its point of meeting the labial sclerite; the stipital sclerite 

 is always present but it may be short; the cardo is visible in some 

 genera as a lightly sclerotized plate; the labial sclerite is roughly 

 triangular in shape; the labral sclerite is present and its median part 

 is lightly sclerotized and often bilobed; the mandible in most genera 

 has a slender blade with a row of fine teeth on the dorsal and on the 

 ventral surfaces (but Tromatohia appears to have only a dorsal row 

 of teeth, and in Delomerista di'prionis Cushman the blade is bifurcated) ; 

 the antenna is papilliform; the closing apparatus of the spiracle is 

 narrower than the atrium and is usually separated from the atrium 

 by a length of trachea equal in length to that of the closing appa- 

 ratus, although in Alophosternum the closing apparatus is long and 

 slender; the skin has well developed setae which are usually equal 

 in length to the blade of the mandible; in Tromatohia the setae are 

 very small and groups of spines are present; spines are absent from 

 other genera of the tribe. 



Larval Key 



1. Small lobes present on ventral edge of labial sclerite ^ 2 



Small lobes not present on ventral edge of labial sclerite 3 



2. Hypostomal spur as broad as or broader than posterior part of hypostoma. 



Calliephialtes, Ephialtes 

 Hypostomal spur more narrow than posterior part of hypostoma . . Scambus 



3. Mandible with blade bifurcated 8 Delomerista 



Mandible with blade not bifurcated 4 



4. Enlargement present on posterior part of hypostoma Iseropus 



Enlargement not present on posterior part of hypostoma 5 



5. Slender epistomal arch present Tromatobia 



Epistomal arch absent Alophosternum 



' Except Scambus pomorum (Ratzeburg) (Imms, 1918; Speyor, 1920) and Calliephialtes dimorphus Cush- 

 man (Sauer, 1939). 



' Except Delomerista sp. (Morris, Cameron and Jep.son, 1937). 



