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Suborder APOCRITA 



By Karl V. Krombein 



This suborder includes a vast and diverse assemblage of species-level taxa, and many more 

 genus- and family-level taxa than does the suborder Symphyta. Other names used in the past for 

 the suborder include PetioHventres or Petiolata, Clistogastra and Heterophaga. Common names 

 applied to the major groups of Apocrita include braconid and ichneumonid wasps, chalcid flies or 

 wasps, gall wasps, ants, true wasps and bees. The first three groups are sometimes placed in the 

 Division Parasitica or Terebrantia, and the latter three in the Division Aculeata. More detailed 

 information is included under the divisional headings. 



There are several important characters separating the Apocrita from the Symphyta. The ap- 

 parent thorax is separated from the apparent abdomen by a constriction. What appears to be the 

 thorax actually consists of the true thorax to which is fused the first abdominal segment 

 (propodeum); the apparent thorax is sometimes termed the mesosoma or alitrunk. What appears 

 to be the entire abdomen is termed the gaster or metasoma. The venation, especially that of the 

 hind wing, is reduced in size and has fewer veins and cells than in Symphyta. The larvae are 

 maggot-like and apodous; some have fleshy pseudopods on the thorax or abdomen which assist 

 in very limited locomotion but which are not homologous with the thoracic prolegs found in most 

 sawflies. 



The majority of larval Apocrita, including the most primitive, are entomophagous. However, 

 phytophagy has developed independently in many higher groups such as some Chalcidoidea, 

 most Cynipoidea, a few Vespoidea and the Apoidea. 



There are some fifteen times as many Apocrita recorded from North America as Symphyta. 

 However, it is virtually certain that this ratio will be substantially increased in the future when 

 the smaller Parasitica are more thoroughly collected and studied. 



Taxonomy: Rasnitsyn, 1975. Akad. Nauk SSSR, Palaeont. Inst., Trans. 147: 1-132, 8 pis. 

 (Mesozoic Apocrita). —Rasnitsyn, 1975. Akad. Nauk SSSR, Zool. Zhur. 54: 848-860, 1 pi. 

 (early evolution). 



Biology: Clausen, 1940. Entomophagous Insects, 688 pp., 257 figs. 



