238 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



while recently at Puente, counted between 40 and 50 adults 



on a single plant of Nicotiana glaucti infested by the bean 



thrips and it is now almost impossible to collect Heliothrips 



fasciatus at Compton, where this parasite was first discovered. 



A TENDENCY TOWARDS POSTERIOR ERYTHRIZATION IN 

 THE PSAMMOCHARID^. 



(Hymenoptera.) 

 BY NATHAN BANKS. 



Recently in examining some of our psammocharid wasps I 

 noticed that there were forms that were practically mutants 

 of the typical form of the species, and that in all cases this 

 mutant was distinguished by having more red on the hind legs 

 or abdomen than in the normal form of the species. I exhibit 

 seven examples of this in six genera. 



(1) Psammochares fuscipennis, and a mutant, var. georgi- 

 atia, which has the abdomen all red and the hind legs reddish. 



(2) Aporinellus fasciatus, a common black species, and a 

 torm, A.ferrugineipes, with reddish legs. 



(3) Ceropales bipunctata, which normally has hind femora 

 red, and a variety (tibialis} in which the hind tibia; are also 

 reddish. 



(4) Pseudagenia niexicana, which typically has b'.ack 

 coxae, and a variety {jlavicoxce) in which the coxae are yel- 

 lowish red. 



(5) Pseudagenia mellipes, with normally black coxae, and 

 a variety {adjunctti) with the coxae n and in reddish. 



(6) Episyron atrytone, all black, and a species almost ex- 

 actly the same, except with reddish hind temora.(E.posterus). 



(7) Batazonns algidus, with black legs, and a variety with 

 reddish legs. 



These are not examples of extremes of variation; I have 

 seen several of each, always alike, and without gradations. 

 The species or varieties differ from each other in scarcely any 

 character except this increase of red; therefore it seems evi- 

 dent that in this family there is a tendency to produce mutants 

 with more red posteriorly than in the typical form. 



I have not noticed such a form of mutation in any other 

 group, although doubtless there are such. 



Various spiders that in the East are green become more or 

 less marked with red in the West, but the amount of red is 

 extremely variable. 



These mutants of the Psammocharidae all come from the 

 South, while the typical form occurs much farther north, as 

 well as in the South. 



