REVISION OF STREPSIPTERA PIERCE. 



43 



Genus .4 ndrena sg. 

 A ndrena. 



Genus Stylops. 



Range. 



Season. 



Flowers. 



salicifloris Cockerell. 



salicifloris Pierce. . 



Vancouver, Brit- 

 ish Columbia, 

 Washington. 



Apr. 4 to June 

 3. 



Ribet, Salix. 



hip pot eg Robertson. 



hippotes Pierce 



Washington, Ore- 



Apr. 21 to June 



Angelica, Ctlastrus, Salix, 







gon, Wisconsin, 



2G. 



Spirxa, Prunus, Vibur- 







Illinois, Ohio. 





num. 



Since Andrena cravsfordi is a new species, and the material belonging 

 to Mr. Crawford and the author is typical, it may be of interest to 

 introduce the records taken to date. Sitilias caroliniana is the typical 

 flower. During 1905 none were collected on anything else. During 

 1906 104 male bees and 100 female bees were taken at this flower; 

 9 male bees and 9 female bees were taken at Serinea oppositifolia; 

 34 male bees and 5 parasitized female bees were taken at Lindlieimera 

 texana, 3 male bees at Engelmannia pinnatfida, and 1 male at a 

 species of Aplopappus. 



A few characteristics have been provisionally set down for the 

 divisions of the old genus Andrena, some of which may be of interest. 

 Ptilandrend is supposed to be generally oligotropic and vernal ; Opan- 

 drena and Trachandrena are vernal; Andrena is vernal with the 

 exception of A. nubecula; Pterandrena is autumnal with a few excep- 

 tions. Pterandrena and Opandrena are characterized hy yellow face 

 markings in the males, and hence here are to be found those species 

 which will show color variation on the clypeus of parasitized indi- 

 viduals. By vernal is meant that the bees finish their flight before 

 July 30. 



e. Food habits of immature hosts. — The manner of feeding the young 

 or of starting them into life has a very direct bearing on the economy 

 of the parasites. For purposes of convenience this subject is divided 

 into three groups. 



Autophagous larvae. — Those larvae which are entirely self-feeding and 

 not dependent upon the parent for more than the deposition of the 

 egg in a proper place may be known as autophagous (from wj-bi = 

 self + (fiayfcv = to feed). The homopterous, heteropterous, and 

 orthopterous hosts are all autophagous, and furthermore are open-air 

 feeders, thus enabling the triungulinids to attack them at any time 

 during their larval period. 



Ghilopliagous larvse. — Those young which feed upon stored up or 

 foraged provisions are here designated as chilophagous (from % C ^C — 

 forage + <j>aysiv = to feed). Under this group may be placed the 

 Sphecoidea with the exception of some Bembecidae, and the Apoidea. 

 All hosts which store food for their young, that is trophapothetic 

 insects (from zpocpr) = food + a-bdzocg = storing), w T hich seal the 



