FAMILY RUGACEAE 



1219 



RODIDAE). Not through egg of insect 

 vector. Not by inoculation of expressed 

 juice. Not through soil. Not through 

 seeds from diseased plants. 



Literature : Bailey, Empire Cotton 

 Growing Rev., 11, 193-4, 280; Kirkpatrick, 

 Bull. Entom. Res., 21, 1930, 127-137; 22, 

 1931, 323-363. 



3. Puga bemisiae H. (Holmes, loc. 

 cit,., 117; Ochrosticta bemisiae McKinney, 

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

 149.) From New Latin Bemisia, generic 

 name of insect vector. 



Common names : Cassava-mosaic virus, 

 cassava Krauselkrankheit virus. 



Hosts: EUPHORBIACEAE—Mani- 

 hot utilissima Pohl, cassava; M. palmata 

 Muell.; M. dulcis. 



Geographical distribution: Gold Coast, 

 Belgian Congo, French Cameroons, Rho- 

 desia, Liberia, Madagascar, probably 

 throughout Africa and adjacent islands; 

 Java. 



Induced disease : In Manihot utilissima, 

 leaves unsymmetrical, curled, distorted, 

 mottled; internodes shortened, plants 

 stunted. Axillary buds produce an extra 

 number of side branches. 



Transmission: By white-flies (ALEY- 

 RODIDAE), Bemisia nigeriensis Corb., 

 in Southern Nigeria, and B. gossypiperda 

 Misra and Lamba, in Belgian Congo and 

 Tanganyika. White-flies infect only 

 young leaves. Not by needle-puncture, 

 rubbing, or hypodermic-needle injection 

 of juice expressed from diseased plants. 



Literature : Dade, Yearbk. Dept. Agr. 

 Gold Coast, 1930, 245; Dufrenoy and 

 Hedin, Rev. Bot. Appl., 9, 1929, 361-365; 

 Golding, Trop. Agric, Trinidad, 13, 

 1936, 182-186; Kufferath and Ghesquiere, 

 Compt. rend. Soc. Biol. Beige, 109, 1932, 

 1146; Lefevre, Bull. Agr. Congo Beige, 

 26, 1935, 442; McKinney, Jour. Agr. Res., 

 39, 1929, 557-578; Muller, Bull. Inst. 

 Plantenziekt., 24, 1931, 1-17; Pascalet, 

 Agron. Colon., 21, 1932, 117; Staner, Bull. 

 Agr. Congo Beige, 22, 1931, 75; Storey, 

 East Afr. Jour., 2, 1936, 34-39 ; Storey and 

 Nichols, Ann. Appl. Biol., 25, 1938, 790- 

 806; Zimmermann, Pflanzer, 2, 1906, 145. 



4. Ruga verrucosans Carsner and Ben- 

 nett. {Chlorogenus eutetlicola (in error 

 for eutettigicola, from New Latin Eutettix, 

 genus name of a vector, and Latin -cola, 

 dweller in or inhabitant of) Holmes, 1939, 

 loc. cit., 11 ; Carsner and Bennett, Science 

 98, 1943, 386.) From Latin, meaning: 

 causing rough swellings. 



Common name : Sugar-beet curly-top 

 virus. 



Hosts : Very wide range in many fami- 

 lies of dicotyledonous plants. Among 

 the horticulturally important host plants 

 are the sugar beet {Beta vulgaris L., 

 CHENOPODIACEAE); bean {Phase- 

 oliis vulgaris L., LEGUMINOSAE); 

 squash {Cucurbita species, CUCURBI- 

 TACEAE) ; and tomato {Ly coper sicon 

 esculcntumUiW., SOLAN ACE AE). 



Geographical distribution : Western 

 North America; in Argentina a strain of 

 virus thought to belong here has been 

 reported but has not yet been fully de- 

 scribed. 



Induced disease : In beet, clearing of 

 veins, leaf curling, sharp protuberances 

 from veins on lower surface of leaves, 

 increase in number of rootlets, phloem 

 degeneration followed by formation of 

 supernumerary sieve tubes, retardation 

 of growth. In tomato, (western yellow 

 blight or tomato yellows), phloem de- 

 generation followed by formation of su- 

 pernumerary sieve tubes, retardation of 

 growth, dropping of flowers and buds, 

 rolling, yellowing and thickening of leaves, 

 root decay, usually followed by death, 

 sometimes by recovery. Occasionally 

 there is relapse after recovery. In cucur- 

 bitaceous plants, stunting, bending up- 

 ward of tip of runner, yellowing of old 

 leaves, abnormally deep green in tip 

 leaves and stem; Marblehead squash is 

 tolerant, showing only mild witches' 

 broom formation and phyllody. In bean, 

 infected when young, thickening and 

 downward curling of first trifoliate leaf, 

 which becomes brittle and will break 

 easily from the stem; leaves become 

 chlorotic, plant stops growing and usually 

 dies soon; older plants are also suscepti- 

 ble to infection; they may survive until 



