ICHNEUMONID FINAL INSTAR LARVAE — SHORT 459 



(Beii-ne, 1941); the hypostomal spur is very lightly sclerotized; the 

 stipital sclerite is slender and its lateral end has a small enlargement 

 bearing a sensillum; the labial sclerite is slender; the silk press is not 

 sclerotized; each maxillary and labial palp bears two sensLlla,one large 

 and one small; there is no prelabial sclerite and no labral sclerite; 

 two small sensilla are present on the labrum, but labral, maxillary, 

 and prelabial setae appear to be absent; the form of the mandible is 

 distinctive, the base having only the circumference sclerotized and 

 with the blade long, slender, and slightly curved; the width of the 

 base of the mandible is approximately equal to two-thirds the length of 

 the blade ; the spiracle is relatively small and the length of the thin-walled 

 closing apparatus, which adjoins the atrium, is approximately equal 

 to twice the depth of the atrium; the skin bears small projections but 

 setae could not be seen. 



Larval Key 



1. Hypostoma with only median part sclerotized Mesochorus 



Hypostoma with entire length sclerotized Astiphromma i* 



The following are figured in the literature : Mesochorus fulgurans 

 Curtis (Beirne, 1941), M. vitticollis Holmgren (Beirne, 1943). 



The A4esochorinae follow the Anomalinae in the classification by 

 Walldey (1958). The larval characters of the Mesochorinae are very 

 different from those of the Anomalinae and in the present study the 

 Mesochorinae have been placed near the Lissonotinae. The rounded 

 labial sclerite of the Mesochorinae resembles that of the Lissonotinae. 

 The mandible, however, is distinctive in form and differs from that 

 of all other Ichneumonids. On larval characters the Mesochorinae 

 are best regarded as an isolated group. 



Subfamily Lissonotinae 



Figures 38-40 



Members of this subfamily are internal parasites of caterpillars. 



The characters show relationships to those of the Ophioninae and 

 Mesoleiinae. The epistoma is not sclerotized dorsally except in 

 Exetastes; the pleurostoma is lightly sclerotized to well sclerotized; 

 the hypostoma is long in the Glyptini and Banchini, but in the 

 Lissonotini it is short and does not extend laterally beyond the lateral 

 end of the stipital sclerite; the hypostomal spur and stipital sclerite 

 are well developed; the labial sclerite, which is relatively large, is 

 basically round to oval and the ventral part is often lightly sclerotized 

 or unsclerotized; the silk press is large; a prelabial sclerite is usually 

 present and two sensilla are situated on this sclerite; each maxillary 



I'OfBeime (1941). 



