BAKER, PLANT LOUSE PARASITES 25 



Legs throughout, mandibles face, first article of antennae and tips only of 

 second, honey yellow. Metanotum smooth and shining, with an undivided 

 median carina and two large shallow pits behind. 

 Ormsby County, Nevada. Coll. C. F. Baker. 



Genus Diaeretu.s Forst 



Among several California species there is one common form which is quite 

 different from any described eastern species, and which is as yet undescribed. 

 It is nearest to D. americanus Ashm. , but lacks any trace of cubitus, and has 

 antennae far shorter than the body. 



Diaeretus calif ornicus n. sp. 



Female: Length 2.5 mm. Black, shining, petiole and metanotum piceous, 

 the latter with a strong median keel, which is split behind, the lateral faces 

 posteriorly each with a large circular, bordered depression. Legs ferruginous, 

 the hind coxae black. Antennae H-jointed, piceous, the first two articles 

 yellowish. 



Reared from plant lice on wild mustard, at Claremont, California, and also 

 taken commonly in general collecting. 



