466 PROCEEDINGS OF THE NATIONAL MUSEUM vol. no 



of the Ophioninae, Campoplegini, and, •with the exception of Opheltes, 

 differs from that of the remaining Mesoleiinae. 



It has not been found possible to separate the ^Mesoleihii and Eury- 

 proctini on larval characters. Lamachus and Hypsantyx with their 

 incomplete labial sclerites, the dorsal ends of which hare bubble-like 

 projections, resemble the Eurvproctini rather than Opheltes, Mesoleius 

 and Lopkyroplectus. 



Townes and Townes (1951) place Opheltes in a subtribe Perilissina 

 and Mesoleius and Lamachus in a subtribe Mesoleiina of the Mesoleiini. 

 The larval characters do not appear to support this grouping. 



Larval Key 



1. Mandible ^-ith rounded and very lightly sclerotized base and very small 



sclerotized blade of length less than radius of base Pionini 



Mandible not of this form 2 



2. Labial sclerite with ventral part expanded into plate constituting almost half 



length of sclerite Euceratini 



Labial sclerite not of this form 3 



3. A hghtly sclerotized plate is present across labrum, and the labral setae are 



situated on this plate Scolobatini 



A Ughtly sclerotized plate not present on labrum 4 



4. Labial sclerite vrith ventral part well sclerotized or, if not, then as well 



sclerotized as lateral parts. 



Opheltes, Mesoleius, and Lopkyroplectus of Mesoleiini 

 Labial sclerite with ventral part unsclerotized or not as well sclerotized as 

 lateral parts. 



Eiiryproctini, and Lamachus and Hypsantyx of Mesoleiini 



Tribe Scolobatini 



Figure 41a 



Members of this tribe are parasitic on argid sawflies. 



Scolobates auricnlatiLS (Fabricus) (CDA) was examined. The 

 mandibles of this species resemble those of the Ophioninae, 

 Campoplegini, but the remaining characters are similar to those of 

 many Mesoleiinae. 



Distinctive structures are the hghtly sclerotized bar across the 

 labrum and a lightly sclerotized plate which appears to be present on 

 the dorsal surface of the food meatus. This may be the suspensorium 

 of the hypophar\Tix (see Short, 1952, figs. 6-8) but, as seen in a cast 

 skin, it appears to be present on the dorsal surface of the food meatus 

 and therefore distinct from the suspensorium. Living material 

 could not be obtained for sections to decide this point. 



