1162 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



sect is usually between 11 and 29 days, 

 although shorter periods have been dem- 

 onstrated in a few cases. Virus may per- 

 sist in the insect host until death, but 

 may become exhausted earlier. Not by 

 aphid, Aphis maidis Fitch (APIIIDI- 

 DAE). Not by inoculation of expressed 

 juice. 



Literature: Briton-Jones, Trop. Agr., 

 10, 1933, 119-122; Carter, Ann. Ent. Soc. 

 Am., 34, 1941, 551-556; Kunkel, Bull. 

 Hawaiian Sugar Planters' Assoc, Bot. 

 Ser., 3, 1921, 44-57; 1924, 108-114; 

 Hawaiian Planters' Rec, 26, 1922, 

 58-64; Phytopath., 17, 1927, 41 (Abst.); 

 Stahl, Trop. PI. Res. Found., Bull. 7, 

 1927; Storey, Rept. of Plant Pathologist, 

 Amani Agr. Res. Station, 4th Ann. 

 Rept., 1931-32, pp. 8-13. 



6. Fractilinea avenae McKinney. 

 (Jour. Washington Acad. Sci., 34, 1944, 

 327.) From Latin avena, oats. 



Common name : Pupation-disease virus. 



Hosts: GRAM I NEAE— Avena saliva 

 L., oat; Triticuvi aesiivum L., wheat; 



Echinochloa crusgalli Beauv.; Setaria 

 viridis; rarely, Agropyron repens (L.) 

 Beauv. and Bromus inerviis Leyss. Ex- 

 perimentally, also Hordeum vulgare L., 

 barley; Panicum miliaceum L., millet; 

 Oryza sativa L., rice; Secale cereale L., 

 rye; Zea mays L., corn (maize). 



Geographical distribution : West Si- 

 beria. 



Induced disease- In oat, chlorotic 

 mottling, profuse development of shoots, 

 proliferation pf flowers with change to 

 leaf-like structures. Protein crystals in 

 affected cells have been regarded as 

 accumulated virus. 



Transmission : By leaf hopper, Delphax 

 striatella Fallan (FULGORIDAE), es- 

 pecially first and second instar nymphs; 

 fifth instar nearly immune to infection. 

 Incubation period, 6 days or more. Virus 

 overwinters in insect as well as in plants. 

 Not transmitted from an infected leaf- 

 hopper to its progeny. Not through soil. 

 Not through seeds from infected plants. 



Literature : Sukhov et al., Compt. rend. 

 Acad. Sci., U. R. S. S., 30, 1938, 745-748; 

 26, 1940, 479-482, 483-486. 



