FAMILY CHLOEOGENACEAE 1145 



SuBORDEK II. Phytophagineae suboirlo novus. 



Viruses infecting higher plants; vectors typically homopterous or hemipterous 

 insects (leafhoppers, aphids, white flies, true bugs) or thysanopterous insects 

 (thrips). From Greek phagein, to eat, and phyton, a plant. 



Key to the families of suborder Phytophagineae. 



1. Inducing j-ellows-tj^pe diseases; vectors t^'pically cicadellid or fulgorid leaf- 



hoppers. 



Family I. Chlorogenaceae, p. 1145. 



2. Inducing mosaic diseases ; vectors typically aphids. 



Family II. Marmoraceae, p. 1163. 



3. Inducing ringspot diseases; vectors unknown. 



Family III. Annulaceae, p. 1212. 



4. Inducing leaf -curl diseases; vectors typically white flies. 



Family IV. Rugaceae, p. 1218. 



5. Inducing leaf-savoying diseases; vectors, true bugs. 



Family V. Savoiaceae, p. 1221. 



6. Inducing spotted wilt; vectors, thrips. 



Family VI. Lethaceae, p. 1223. 



FAMILY I. CHLOROGENACEAE HOLMES EMEND. 



(Handb. Phytopath. Viruses, 1939, 1.) 



Viruses of the Yellows-Disease Group; pathogenic in flowering plants, causing dis- 

 eases in which effects on chlorophyll are usually diffuse or stripe-like, no typical spot- 

 ting or spotty mottling being involved. Vectors, so far as known, leafhoppers (CICA- 

 DELLIDAE and F ULGORIDAE) . 



Key to the genera of family Chlorogenaceae. 



I. True Yellows Group. Viruses inducing diseases usually characterized by 

 stimulation of normally dormant and adventitious buds to produce numer- 

 ous slender shoots with long internodes and by chlorosis without spotting; 

 invaded parts abnormallj' erect in habit. Vectors cicadellid leafhoppers 

 so far as known . 



Genus I. Chlorogenns, p. 1146. 

 II. Peach X-Disease Group. Viruses inducing diseases characterized by reset- 

 ting of foliage and sometimes death of host. 

 Genus II. Carpophthora, p. 1151. 

 III. Phloem-Necrosis Group. Viruses inducing diseases characterized by 

 progressive degeneration of the host plant or by wilting and sudden death ; 

 sometimes by root discoloration. Vectors cicadellid leafhoppers so far as 

 known. 

 Genus III. Morsus, p. 1153. 

 IV. Yellow-Dwarf Group. Viruses inducing diseases characterized by chlorotic 

 effects somewhat resembling true mottling but often more diffuse. Vectors 

 cicadellid (agallian) leafhoppers. 

 Genus IV. Aureogenus, p. 1154. 

 V. Fiji-Disease Group. Viruses inducing diseases characterized by marked 

 vascular proliferation. The vector of one is known to be a leafhopper of 

 the subfamily Delphacinae, family FULGORIDAE. 

 Genus V. Galla, p. 1157. 



