Apr. 3-sept. 25, 1916 Illustrations xxiii 



Page 

 Fig. 3. Graph showing the effect of heat on the nitrogen-fixing power of soil 



treated and not treated with arsenic 409 



4. Effect of various arsenic compounds in the ratio of 400 parts of the 



compound to r, 000,000 parts of soil on the activity of various soil 

 organisms 411 



5. Graph showing parts per million of various arsenic compounds in the 



soil at which the greatest stimulation occtu-red 412 



Transmission and Controi, o? Bacterial Wilt op Cucurbits 



Fig. I. Comparison of the amount of wilt with striped-beetle prevalence and 

 with meteorological phenomena in three fields, East Marion, Long 

 Island, N. Y., season of 1915 421 



2. Comparison of relative wilt control of Bordeaux mixture plus lead 



arsenate, Bordeaux mixture alone, and lead arsenate alone in field i. 



East Marion, Long Island, season of 1915 430 



3. Curves showing relative wilt control of Bordeaux mixture and lead 



arsenate with date of first application as a variant in field i, East 

 Marion, Long Island, season of 1915 431 



Aleyrodidae, or White Flies, Attacking the Orange, with Descrip- 

 tion OP Three New Species of Economic Importance 



Fig. I. Aleurocanthus citriperdus: A, Pupa case; B, egg; C, polygonal mark- 

 ings of egg; D, vasiform orifice of pupa case; E, spine from dorsum 

 of pupa case; F, margin of pupa case; G, genitalia of adult male; 

 H, forewing of male; /, antenna of pupa case; /, leg of pupa case; 

 K, L, marginal teeth, much enlarged; M, central swollen spine from 

 dorsal area 460 



2. Aleurocanthus woglumi: A, Egg; B, polygonal markings of egg; C, pupa 



case; D, margin of pupa case; E, vasiform orifice of pupa case; 

 F, forewing of adult female; G, same, showing variation in markings; 

 H, costal margin at base of wing of female; /, forewing of male; 

 /, male genitalia 462 



3. Aleurothrixus porteri, A. howardi, and A. floccosus: A, Akurothrixus 



porteri: Larva, first instar. B, A. porteri: Caudal spine of pupa 

 case. C, A. porteri: Clasper of male. D, A. porteri: Egg. E, A. 

 howardi: Caudal spine. F, A. porteri: P*upa case. G, A. porteri: 

 Forewing of adult. H, A. floccosus: Vasiform orifice of pupa case. 

 7, A . porteri: Vasiform orifice of pupa case. /, A . houardi: Vasiform 

 orifice of pupa case. K, A. porteri: Margin of pupa case. L, A. 

 Porteri: Margin of early larva 467 



Relative Water Requirement of Corn and the Sorghums 



Fig. I. Curves of the evaporation at Garden City, Kans., for the growing period 



of 1915 474 



California Green Lacewing Fly 



Fig. 1. The California green lacewing fly: Adult 515 



2. Chrysopa californica: Eggs 518 



3. Chrysopa californica: First instar 519 



4. Chrysopa californica: Third instar 521 



5. Chrysopa californica: Pupal case 522 



6. Chrysopa californica: Pupa 522 



7. Chrysopa californica: Pupa freshly emerged from its cocoon 523 



