178 



partially immune, plants are : Most of the fine grasses, including 

 crabgrass ; most of the varieties of maize and wheat ; rye ; some 

 varieties of oats ; velvet beans, and beggarweed. Iron and Brabham 

 cowpeas are usually resistant ; onions, parsnips, strawberries and 

 turnips are slightly affected. When growing any of these plants to 

 free the land from root-knot, it is important that all weeds (especially 

 careless weed or Amaranth) should be destroyed. A hst of forty 

 Florida plants liable to severe attacks is given. 



Euthrips tritici projectus (the grain thrips) occasionally does a great 

 deal of damage to tomatoes. The eggs are laid just beneath the sur- 

 face of the plant tissue in a shallow slit, and under favourable conditions 

 a generation occurs every two or three weeks. Upon hatching, the 

 young at once attack the tenderesfc part of the blossom or bud. Tobacco 

 decoctions are very effective against this insect, but in spraying, care 

 must be taken to cover the blossom or bud so thoroughly with the 

 solution that the insects cannot emerge without getting wet. As. 

 much pressure as possible should be used, for the double purpose of 

 driving the spray into the blossoms, and of frightening the thrips out 

 by force of the impact of the liquid against the flower. Black Leaf 40 

 should be used in the proportion of about one part to 1,000-1,800 

 of water ; the weaker solutions in about one to 100 ; while one part of 

 home-made tobacco extract should be used with about ten of water. 

 It is advisable to use an adhesive. In April 1912, the author used 

 the following mixture on tomatoes : Black Leaf 40, 3| oz., commercial 

 hme-sulphur, 2^ qts., and water, 50 U.S. (41| Impl.) gallons, with the 

 result that about 75 per cent, of the thrips present were killed. Lead 

 arsenate or zinc arsenite can be substituted for the lime-sulphur if it 

 is wished to kill the tomato worms or other gnawing insects at the same 

 time ; four or five pounds of whale-oil soap may also be substituted 

 for the lime-sulphur. Flour paste makes an excellent spreader for 

 these tobacco extracts [see this Review, Ser. A, ii, p. 82]. 



Cutworms are mentioned as attacking newly-set tomato plants, and 

 two species, LycopJwtia {Agrotis) saucia and Scotogramnm trifolii 

 (Mamestra chenopodii), are figured. Early ploughing, and the use of 

 poisoned bran or cottonseed meal are recommended. The two Sphingids 

 most hkely to prove destructive to tomatoes in Florida are Proto- 

 parce qumquemaculata (Northern tobacco worm) and P. sexta 

 (Southern hornworm), the latter being much more common in that 

 State. The pupae from the first brood of larvae appear in North 

 Florida in July. The caterpillars are partially controlled by Tachinids. 

 and by the Braconid, Apanteles glomeratus. Hand-picking is effective, 

 or the plants may be sprayed with lead arsenate or zinc arsenite ; 

 Paris green may also be used. 



Eriophyes caladadophora, the mite which causes " white-mould," 

 a disease giving the tomato plants a white, fuzzy appearance of the 

 upper portion of the stem, is rarely seen as a tomato pest outside 

 Florida. The following sulphur spray is recommended against it : 

 Caustic soda (98 per cent.) 10 lb., flowers of sulphur 20 lb., and water 

 20 U.S. (16| Impl.) gallons. Other good remedies are : Lime-sulphur 

 solution and dry sulphur, with or without lime. Kerosene emulsion, 

 whale-oil or fish-oil soap, tobacco decoctions, and tobacco extracts 

 are recommended against the tomato aphids, Megoura solani and 

 Myzus persicae ; while flea-beetles, which often attack the leaves and 



