ICHNEUMONID FINAL INSTAR LARVAE — SHORT 399 



In the following descriptions of larval structure in the various 

 subfamilies, a list of species studied is given. A list is also given of 

 those descriptions in the literature which were thought sufficiently- 

 accurate and detailed to help workers in identifying material. The 

 standard of published descriptions of ichneumonid larvae is still poor 

 despite Beirne's (1941) paper, and many references to descriptions 

 have been omitted since the figures given are too small and vague. 



The biological notes given for the various subfamilies and tribes 

 are based on those of Townes and Townes (1951) and Walkley (1958). 

 The subfamilies, tribes and genera are considered in the order given 

 by Townes and Townes (1951), or Walldey (1958), except in the case 

 of the Mesochorinae, which are moved from a position following the 

 Anomalinae and placed near the Lissonotinae for reasons stated in 

 the section dealing with the Mesochorinae. The species are considered 

 in alphabetical order. When genera are added to the list of Walkley 

 they are placed near what were thought, on larval characters, to be 

 closely related genera. 



Subfamily Pimplinae 



Figures 2-10 



On larval characters the Pimplinae fall into two groups; in one are 

 the Pimplini and in the other are the Ephialtini, Polysphinctini, 

 Neoxoridini, Rhj^ssini, Theroniini, Labenini, and Xoridini. The 

 Acaenitini have a special position. The Pimplini usually have the 

 epistoma well sclerotized, the hypostoma short, and the mandible 

 large and without teeth. The labial sclerite is longer than wide and 

 its ventral side is broad. The labral sclerite is absent. The setae on 

 the skin are small. In the second group the epistoma is, at most, 

 lightly sclerotized, and the hypostoma is long. The mandibles are 

 relatively smaller than in the Pimplini and they usually bear teeth. 

 The form of the mandible is similar in the Ephialtini, Neoxoridini, 

 Rhyssini, and Labenini in having a slender blade and a dorsal and 

 ventral row of small teeth. In the Theronimi and in Delomerista 

 (Ephialtini) the blade of the mandible is bifurcated, one part having 

 dorsal and ventral teeth and the other being toothless. The labial 

 sclerite is basically triangular in shape, although in the Rhyssini and 

 Neoxoridini the labial sclerite is pointed ventrally, and in the Theroni- 

 ini the ventral part of the labial sclerite is broad so that the sclerite 

 resembles that of the Pimplini and Acaenitini. The labral sclerite is 

 present. The setae on the skin are relatively longer than in the first 

 group. The Acaenitini show characters of both groups. The man- 

 dible is similar to that of the Pimplini, and the absence of the labral 

 sclerite and the presence of a sclerotized epistoma also suggest this 



