NO. 3533 CHALCID WASPS OF GENUS EURYTOMA — BUGBEE 493 



collections consisted of only one or two specimens. Too often the 

 host was not indicated or only the host plant was named from which 

 the parasite Avas bred. Exact relationships of host and parasite, 

 therefore, were impossible to determine in many cases. 



The results of this study must be considered as only tentative. 

 The need for more material from additional localities, plus more 

 exact determinations of host relationships, will lead to clearer defini- 

 tions of the species of the complex in the future. Nevertheless the 

 importance of these parasites, occurring as they do on many hosts 

 of economic importance, makes it necessary to make some attempt to 

 put the classification of the parasites on a more realistic basis. The 

 redescription is based on the holotype female, allotype male, and an 

 additional series of 7 females in the U.S. National Museum collection, 

 Washington, D.C. 



This species has its closest aflanities with the Eurytoma pini, E. 

 diastrophi, and E. bolteri group of species. The whole complex is 

 probably associated with the larvae of weevils and small moths that 

 live in stems of various species of plants. They act as either primary 

 or secondary parasites. Hosts listed for the specimens of E. tyloder- 

 matis exammed include: Trichobaris texana, which is reported to 

 occur in stems of Solanum rosiratum; Lixus scrobicollis in stems of 

 Ambrosia trijida (Pierce, 1908 a, b, and c; Pierce, Cushman and Hood, 

 1912); Tyloderma Joveolatum in the stems of Oenothera biennis; Mom- 

 pha eloisella also m stems of 0. biennis. Additional possibilities 

 reported in the Hterature include Trichobaris trinotata in Solanum 

 carolinense (Chittenden, 1911) and Lixus musculus, in Polygonum 

 pennsylvanicum (Pierce, 1907); Coleophora malivorella and Tricho- 

 baris rostratum. 



59. Eurytoma gossypii, new species 



Map 26 

 Female: Black. Length averages 4.2 mm. (3.8-4.6). Abdomen 

 plump and oval in lateral view; averages 2.2 mm. (1.9-2.4) in length; 

 long sixth abdominal segment averages .68 mm. (.62-.75); surface 

 of sixth covered by fine shallow pitting which covers all of lateral 

 surface for lower half to three-fourths, then sculpturing recedes 

 toward anterior margin and may continue over dorsal surface in a 

 narrow band. Ninth tergum, mediumly long and pointed; averages 

 .26 mm. in length (.25-.30); anterior half naked and with finely 

 shagreened or smooth surface; posterior half with shallow pits and 

 covered with white pile. Internal genitalia average 2.1 mm. in 

 length; in height 1.2 mm.; anterior expanded plate of dorsal valves 

 averages .20 mm. in width at widest point; dorsal and ventral valves 

 bend dorsally, anterioriy, at about a right angle and stylet arch is in 



