240 



Journal of Agricultural Research 



Vol. XVI, No. 9 



third-stage larva can then be seen attached to the inner ventral wall of 

 the puparium. 



Table V. — Distinguishing characters of the larval stages of Pegomyia calyptrata 



THE LESS COMMON SPECIES, PEGOMYIA AFFINIS 

 HISTORICAL REVIEW 



This species has almost escaped the keen eye of the systematist. It 

 was described by Stein (1897)* as Pegomyia vicina Lintner. Later 

 he noticed his mistake and in the same paper * named the new species 

 "Pegomyia affinis." Since that time there has been no reference to 

 this species. The writer describes for the first time the habits of this 

 interesting anthomyid. 



DISTRIBUTION 



Little or nothing is known about the distribution of P. affinis. Stein' 

 records it rather abundant in Pennsylvania, Vermont, and Illinois. 

 The writer has reared and collected specimens at Ithaca and Florida, 

 N. Y., and Arendtsville, Pa. 



HOST PLANTS 



P. affinis, mines exclusively on Rumex spp. Adults have been reared 

 from R. crispus and R. ohtusifolius. It is possible that other species of 

 Rumex are attacked. 



LIFE HISTORY 



Eggs. — The eggs are much more beautiful than those of P. calyptrata 

 and are pure white in color. They are laid in neat transverse rows of three 

 to five, rarely six or seven, on the under surface of the leaf. They have 

 never been found as abundant as those of the preceding species and 

 never more than three or four groups have been found on a single leaf. 

 The incubation period is given in Table VI. 



•Stein, P. nordamerekanische anthomyidicn. /;z Berlin. Ent. Zeitschr.. Jahrg, 4_>, p. 239-241, 286. 

 1897. 



