16 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 121 



pseudopods lacking, but strong curved hooks may be present on venter 

 of penultimate and/or antepenultimate segment. 



Key to Larvae of Subfamilies of Stratiomyidae of America North of 



Mexico 



1. Last abdominal segment with a coronet of plumose or pinnate setae at the 



apex STRATIOMYINAE 



Last abdominal segment with coronet of plumose or pinnate setae absent 

 from apex 2 



2. Last abdominal segment with a coronet of plumose or pinnate setae on 



dorsum NEMOTELINAE 



Last abdominal segment lacking a coronet of plumose or pinnate setae . . 3 



3. Pro- and mesothoracic segments with a smooth field on dorsum ; anus bordered 



anteriorly by a transverse row of strong, posteriorly directed teeth. 



XYLOMYINAE 



Pro- and mesothoracic segments with normal shagreened pattern on dorsum; 



anus not bordered anteriorly by teeth 4 



4. Mouthparts highly sclerotized and foreshortened, mandibles well developed, 



no setae or bristles present on mouthparts (fig. 15) ; recorded from San 



Francisco area only CHIROMYZINAE 



Mouthparts with a different combination of characters than those listed 

 above; occurring in San Francisco area or elsewhere 5 



5. Dorsal row of transverse setae surrounded by smaller setae; mouthparts as 



in figure 16; uniformly colored larvae BERIDINAE 



Dorsal row of transverse setae not surrounded by smaller setae; mouthparts 

 different than above; larvae uniformly colored or with a pattern .... 5 



6. Larva with a well-developed labium (fig. 19) ; primarily restricted to south- 



western United States, where found in Opuntia or Agave species. 



CLITELLARIINAE, Tribe CLITELLARIINI 



Larva lacking a well-developed labium; occurring in southwestern United 



States and elsewhere; not recorded from hosts given above 7 



7. Small larva, under 10 mm in length; mouthparts similar to those of Beridinae 



(fig. 18) ; found under bark of trees PACHYGASTRINAE 



Larva over 10 mm in length; mouthparts lacking sclerotized areas .... 8 



8. Mouthparts simple, setae restricted to a linear patch on inner margin of 



mandibular-maxillary complex (fig. 21); large, robust, color uniform. 



CLITELLARIINAE, Tribe HERMETIINI 



Mouthparts more elaborate, setae present on mandibular-maxillary complex, 



in addition to setae restricted to notch on inner margin of complex (fig. 17) ; 



smaller, usually with a vittate pattern SARGINAE 



Subfamily Xylomyinae 



This subfamily is represented in North America by the 2 genera 

 Xylomya Rondani and Solva Walker. It is considered the most prim- 

 itive group of the Stratiomyidae because it shares at least 1 charac- 

 ter of the adult stage with the corresponding stage of the generally 

 more primitive Xylophagidae. 



SuBFAMiLiAL CHARACTERS. — Mouthparts as in figure 14. Other 

 characters as given in key to subfamilies. 



