ICHNEUMON-FLIES — GELINAE : MESOSTENINI 9 



visit flowers with exposed nectaries. We have no records of females 

 drinldng blood of hosts, as is common in some other groups of para- 

 sitic Hymenoptera. 



The Mesostenini share all these general characteristics of their 

 subfamily. More specifically, the tribe contains most of the larger 

 species of the subfamily, and species usually more definitely associ- 

 ated with foliage rather than with the soil surface or ground Htter, as 

 in a fair percent of the Gelini and Hemigasterini. Most of the Meso- 

 stenini occur in warm climates, while the Gelini and especially the 

 Hemigasterini are better represented in temperate and cold climates. 



In the tropics Mesostenini are the most conspicuous of all ich- 

 neumonids. A large proportion of the tropic and subtropic species 

 have ruptive and mimicking color patterns and are very attractive in 

 appearance. The southeastern United States has a good represen- 

 tation of species with tropical affinities. Their bright and varied 

 color patterns usually are diagnostic of the species and the majority 

 of our species of this group are illustrated in this paper for easy 

 recognition. The species of Holarctic affinities usually have the 

 black and red or fulvous colors with restricted white markings that 

 are common to ichneumonids of more northern habitats. 



Some of the Mesostenini, particularly those with tropical aflSnities, 

 are more adept than most ichneumonids at stinging when captured. 

 The collector soon learns to handle these with a little care. 



Generic Groupings 



The normal hosts are lepidopterous cocoons. One group {Hi- 

 dryta, Idiolispa, and Trychosis) parasitizes spider egg cocoons. Some 

 of the species of more northern distribution attack sawfly cocoons 

 mainly or exclusively. In these the ovipositor tip tends to have the 

 dorsal valve compressed and rather high, sharp along its dorsal 

 edge, and strongly decurved beyond the nodus. Trachysphyrus 

 luctuosus and Habrocryptoides tsugae have this style of ovipositor. 

 One group of genera parasitizes mainly (or exclusively?) the thin 

 but hard cocoons of Eucleidae. In these the dorsal valve of the 

 ovipositor tip has a series of teeth or transverse ridges and is usually 

 subcylindric. This group is separated as the new subtribe Baryce- 

 ratina. In the Baryceratina we include also Lamprocryptus and 

 Glodianus. These likewise have ridges on the dorsal valve of the 

 ovipositor tip, but the tip is strongly compressed. Their hosts are 

 unknown except that Glodianus bombycivorus was reared from a 

 "bombycid cocoon." 



Some of the genera regularly or occasionally parasitize borers 

 of various kinds, and the adults, especially the females, show various 



589900—62 2 



