VI Journal of Agricultural Research voi.xii 



Interrelations ok Fruit-Fly Parasites in Hawaii 



Plate io. Diachasvm tryoni: A. — Freshly hatched larva with its mandibles Page 

 actually embedded in the body of a newly hatched but dead larva of Opius 

 humilis. B. — Newly hatched larva with its mandibles closed, showing 

 ventral serosal material surrounding the body and the two gill-like appen- 

 dages on the first body segment 296 



Plate h. Diachasma tryoni: A. — Lateral view of larva in the second instar, 

 showing particularly well the f atbody of the host recently taken in as food . 

 B. — Lateral view of a 2 -day-old lai-va engorged with food and about to molt, 

 showing the enlarged and stiffened body 296 



Plate 12. Opiu? humilis: A, B. — Dead larva in first instar; killed by first- 

 stage larva of Diachasma tryoni, showing cut on body made by the attacking 

 larva and mandibles extended in final death struggle. C— Dead larva in 

 first instar; killed by first-stage larva of Diachasma tryoni. D. — Dead larva 

 in first instar; badly lacerated and distorted by attack of first-stage larva of 

 Diachasma tryoni 296 



Plate 13. Opius humilis: A. — Dead larva in first instar, with body shriveled 

 and twisted through attack by first-instar larva of Diachasma tryoni. B. — 

 Dead larva in first instar; killed by first-instar larva of Diachasma tryoni. 

 C. — Dead larva in first instar; killed by first-stage larva of Diachasvia tryoni. 

 D. — Healthy, living larva in first instar. E. — Healthy, uninjured, living 

 larva in first instar 296 



Effect of Season and Crop Growth in Modifying the Soil Extract 



Plate 14. A. — General views of soil containers. B. — Bins for storage of sur- 

 plus soil 368 



Tobacco Wildfire 



Plate 15. Bacterium tabacum: A. — Tobacco leaf, four days after artificial 

 inoculation, showing chlorosis and lesions. B. — Natural infection with 

 brown lesions bordered by tissues of a water-soaked appearance 458 



Plate 16. Bacterium tabacum: A. — Natural infection. Lesions are large and 

 concentrically zonate. B. ^Numerous confluent lesions on one side of 

 the midrib have resulted in distortion of the leaf. C. — Almost the entire 

 leaf is involved and a portion of the rotted tissues have fallen out. Natural 

 infection 458 



Wilt Diseases of Okra and the Verticillium-Wilt Problem 



Plate A. Fusarium vasinfectum on vegetable media: 1-3. — Growth on 

 steamed potato. Both potato cultures show pionnotes. 2, 4. — Growth on 

 rice. Cultures i and 2 were grown in a strong north light; 3 and 4 in a 

 subdued light 546 



Plate 17. A-H. — Verticillium albo-airum: A. — Simple conidiophores and 

 conidia. B. — Same showing, respectively, the collection of the conidia 

 on the sterigma in irregular aggregations in dry air, and in water drops in 

 humid air. C. — Verticillate conidiophores bearing one and three whorls, 

 or virtels, of branches, respectively. D. — Verticillate conidiophore having 

 conidial heads, from humid environment — that is, moisttu-e drops in which 

 the conidia float as in figure B. E. — Mycelium of V. albo-atrum, in the 

 vascular ducts of an okra plant inoculated with this fungus. F, H. — Ger- 

 minating conidia. G. — Swollen, sclerotia-like mycelium. 

 I-M. — Fusarium vasinfectum: I. — Terminal, intercalary and conidial chlamy- 

 dospores. K. — Germinating macroconidium. L. — F. vasinfectum from 

 okra-wilt. M. — F. vasinfectum from cotton-wilt 546 



