144 Hymenoptera in America North of Mexico 



ignore the revolutionary advances in classification made possible by the work of Jurine and 

 reverted to lumping all of the Ichneumonoidea under the generic name Ichneumon (see in- 

 troduction to Ichneumonidae). Consequently, Thunberg's work was largely ignored prior to 

 Roman's (1912) study of his type specimens. 



The actual number of species in the Ichneumonoidea can only be estimated. The Braconidae 

 contains about 2,000 described species in North America and about 10,000 worldwide; the Ichne- 

 umonidae about 3,000 in North America and about 15,000 worldwide. However, the total number 

 of species is estimated to be 60,000 worldwide in the Ichnuemonidae (Townes, 1969, p. 7) and 

 40,000 in the Braconidae. 



Except for Hybrizontidae and Stephanidae, the families of Ichneumonoidea occur in all zoo- 

 graphical regions and in all terrestrial habitats. In the Ichnuemonidae the Western Palearctic 

 fauna is best known followed by the Nearctic, whereas the reverse seems to be true for the 

 Braconidae. As in the case of Chalcidoidea, most of our knowledge of the Ichneumonoidea has 

 been derived from species of economic importance to agriculture. For the vast majority of spe- 

 cies, there is little or no knowledge of biology. 



The ichneumonoids are parasitic on nearly all groups of insects as well as on spiders, and all 

 stages of these hosts are attacked. Aphidiidae, many Braconidae, and possibly Hybrizontidae 

 (hosts of latter unknown) attack paurometabolous insects, while no paurometabolous hosts are 

 known for Ichneumonidae or Stephanidae. The only ichneumonoids which attack adults of 

 holometabolous insects are certain euphorine and blacine Braconidae. Aside from the limitations 

 which have been mentioned, large numbers of Ichneumonoidea are polyphagous and the limits of 

 the host range seem to be related more to the host habitat than to the taxonomy of the host. 



The only families of Ichneumonoidea which are known to include hyperparasitic species are 

 Ichneumonidae and Braconidae, but only a very few Braconidae could be regarded as hyper- 

 parasitic (i.e. a few Euphorinae which attack adult Ichneumonidae). The fact that hyper- 

 parasitism is much more prevalent in the Ichneumonidae than in the Braconidae is explained lar- 

 gely (but not in the case of mesochorine and eucerotine Ichneumonidae) by the fact that certain 

 Ichneumonidae have the habit of attacking hosts which are confined within silken cocoons (e.g. 

 sawfly prepupae, ichneumonoid prepupae, spider eggs, chrysopid eggs, etc.), while this habit has 

 not developed among Braconidae. Further discussion of host relations is deferred to the in- 

 troductions to the various taxa. 



Taxonomy: Jurine, 1807. Nouv. Meth. Class. Hym. Dipt. v. 1, 324 p. and 14 pi. — Gravenhorst, 

 1819 (1818). Nova Acta Leopoldina 9: 281-298. — Nees ab Esenbeck, 1819 (1818). Nova 

 Acta Leopoldina 9: 299-310. — Thunberg, 1822; 1824. Acad. Imp. des Sci. St. Petersburg, 

 Mem. 8: 249-281 (key); 9: 285-368. -Ashmead, 1900. U. S. Natl. Mus., Proc. 23: viii and 220 

 p. (classification of Ichneumonoidea and Evanioidea). —Roman, 1912. Zool. Bidr. Uppsala 

 1: 231-293. -Viereck, 1914. U. S. Natl. Mus., Bui. 83: v and 186 p. (type-species of 

 Ichneumonoidea and Evanioidea). —Viereck, 1921. U. S. Natl. Mus., Proc. 59: 129-150 (sup. 

 to Viereck, 1914). —Townes, 1969. Amer. Ent. Inst., Mem. 11: 2-7. — Eady, 1974. Jour. Ent. 

 (B) 43: 63-72. —Townes, 1975. Ent. News 86: 123-127. —van Achterberg, 1976. Tijdschr. v. 

 Ent. 119: 33-78. 



Family BRACONIDAE 



By Paul M. Marsh 



This is a large and important group of mostly primary parasites. They are closely allied with 

 the Ichneumonidae and can be distinguished by the absence of the second recurrent vein in the 

 forewing. The classification used in this catalog departs somewhat from the former catalog but 

 is, nevertheless, a conservative arrangement and is based on studies made by Telenga (1952), 

 Tobias (1967) and Capek (1969, 1970). This arrangement reflects as much as possible relation- 

 ships among the groups with respect to morphology-larval as well as adult-and biology. The 

 subfamilies Doryctinae, Braconinae, Exothecinae and Rogadinae form a morphologically similar 

 group of unspecialized Braconidae called the Cyclostomi in reference to the circular opening 

 formed by the clypeus and mandibles. The Doryctinae, Braconinae and Exothecinae are ec- 

 toparasites of cryptic host larvae, usually permanently paralyzing the host, and are considered 

 to be the most primitive groups. The Rogadinae, which are endoparasites of lepidopterous lar- 

 vae, represent the transition from external to internal parasitism which is exhibited by the 



