ILLUSTRATIONS. 



Page. 

 Plate I. Leafhoppers {Etitcttix spp.) and their work. Fig. 1. — Eu- 

 tettix tenella: a, Adult; b. nymph; c, wing; d, e, geni- 

 talia; /, eggs (greatly enlarged) ; g, section of beet stem, 

 showing fresh eggs in place; /;, same, showing eggs ready 

 to hatch ; i, old egg scars on beet stems ; j, small leaf of 

 sugar beet, showing characteristic " curly-leaf " condition ; 

 k, enlarged section of back of an extreme case of " curly- 

 leaf,'" showing " warty " condition of veins. Fig. 2.— 

 Eutettix strohi: a. Work of nymphs on lambsquarters; 

 6, work of nymphs on sugar beet. Fig. 3. — Eutettix scit- 

 ula: Adult. Fig. 4. — Eutettix clarivida: a, Wing; h, head 

 and pronotum ; c, d, genitalia. Fig. 5. — Eutettix nigridor- 

 sum: Work of nymphs on leaf of Helianthus. Fig. 6. — 

 Eutettix straminea: Work of nymphs on leaf of another 

 Helianthus. Fig. 7. — Eutettix insana: Wing. Fig. 8. — 



Eutettix striata: a, ft, Genitalia 34 



II. Work of Eutettix tenella on sugar beet. Fig. 1. — Three 

 "curly-leaf" beets, the result of attack by Eutettix tenella, 

 and one normal beet from the same field, showing differ- 

 ence in size. Figs. 2, 3. — "Curly-leaf" beets as seen in 

 the held. Fig. 4. — Normal beets from same field 44 



III. Work of Eutettix tenella on sugar beet. Fig. 1. — A large 



beet becoming " curly." Fig. 2. — Back of a leaf affected 

 by " curly-leaf," showing " warty " condition and curled 

 edges 44 



IV. Work of Eutettix tenella on sugar beet. Fig. 1. — A field of 



beets destroyed by " curly-leaf." Figs. 2, 3. — Cages used 



in the life-history experiments 4G 



(36 — IV 



IV 



