NO. 3533 CHALCID WASPS OF GENUS EURYTOMA — BUGBEE 441 



Propodeum most often at approximately a right angle to the scutel- 

 1am; usually shallowly concave and with or without a median furrow. 



Thorax covered dorsaUy with coarse umbUicate punctures; para- 

 psidal grooves on the mesonotmn complete; pronotum collar-shaped 

 and usually as long as the mesonotum; prepectus alwa3^s present. 



Head usually with umbilicate punctures on vertex, frons, and genae. 



Antenna elbowed; scape attached at the base of a deep scrobal 

 cavity; one small ring joint between pedicle and first joint of the 

 flageUum; flagellum 6- or 7-segmented; if 6-segmented, terminal unit 

 consists of three closely fused segments; otherwise two closely fused 

 segments; antenna usually filiform or wealdy clavate. 



Front coxa always with a shallow oblique depression on anterior 

 face; in a few species depression appears deeper because of a raised 

 carina; foreleg with one cmwed tibial spur and hindleg with two 

 straight tibial spurs. 



Remarks. — The description and summary of the characteristics of 

 the genus Eurytoma are the author's concept of the genus, based on 

 his knowledge of the North American species only. A revision of 

 the genera of the family Eurytomidae on a worldwide basis might 

 narrow or expand the limits of the genus, but as yet such a study 

 has not appeared. 



The genus is worldwide in its distribution with described species 

 from the Arctic Ckcle to Patagonia and southern Africa. Although 

 an accurate count has not been made, there must be in the neighbor- 

 hood of 450 or more described species. 



The author hopes that this treatment of the species of Eurytoma 

 in North America north of Mexico will help increase the knowledge 

 of this large genus and will aid those who are working with the genus 

 in the United States and other countries, presently and in the future. 



The key is restricted to the females because several species of 

 Eurytoma lack males and in some others males occur sporadically 

 in small numbers only. The species are not arranged phylogenetically 

 although some of the more specialized morphologically appear at 

 the beginning of the key and many of the more generalized toward 

 the end. 



Explanation of some of the structures and measurements used in 

 the key appear in a preceding section. 



Key to Species of Eurytoma of North America Based on Female 



1. Abdominal petiole longer than wide; longer than, equal to, or only slightly- 

 shorter than the hindcoxa Group A. Petiolata (p. 442) 



Abdominal petiole short; breadth may be equal to length or greater than 

 length Group B. Brevipetiolata (p. 443) 2 



