()2 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 1 
Promising results were obtained in the control of the red berrj ml «• (J 
phycs essiffi Hassan) In the Puyallup Valley of Washington bj applying lime- 
sulphur sprays during the dormant period of the plant, followed by sprayg 
taining wettable Bulphur or emulsions of n fined petroleum or coal-tar oil, during 
the growth of the plants and np to the time when the fruit begins to ripen. 
BEET LEAFHOPPEB 
In the southern Idaho beet-growing area early-season indications were that 
light Infestation by the beet leafhopper could be expected. This I was 
borne out, but the small number of the Insects from the wild-land breeding areas 
that entered the cultivated fields did not do so until later in the season than 
normally. Consequently this pest did not seriously affect production of beets in 
this section. Progress \v;is made in outlining and mapping the critical breeding 
an ;i- of the Leafhopper. Previously obtained evidence was substantiated to the 
effect that, if given an ample opportunity, the native grasses which are not hosts 
of the leafhopper will replace, through proper land-utilization methods, the intro- 
duced wo.ii hosts of the leafhopper in the desert breeding areas and in aban- 
doned areas that have formerly been under cultivation. Work was continued in 
California, in cooperation with state workers and sugar companies, on the spray- 
ing of desert host plants npon which the leafhopper congregates during certain 
seasons and in the elimination of Russian-thistle, a favorite wild host plant of 
tins insect. The evidence so far indicates that these control methods | •: 
direct benefit in reducing the damage caused by leafhoppers and the curly top 
disease of which they are the vectors. 
Experiments on the control of the beet leafhopper on sugar beets grown for 
seed in Arizona, New Mexico, and Texas, in cooperation with the beet-seed pro- 
ducers, demonstrated that two different pyrethrum extract-oil combinations 
applied in an atomized form to SUgar-beel seed plants and directed against the 
adults or nymphs of the beet leafhopper killed an average of approximately !••"» 
percent of the leafhoppers present. Emphasis during the past season has been 
placed on the relation of leafhopper movements in southern Idaho to curly top 
Injury t«> beans and tomatoes. 
TOBACCO INSECTS 
Experiments in Florida and Tennessee disclosed that a derris or cuhe dust 
mixture containing l percent of rotenone was effective in controlling the tobacco 
Ilea beetle in the plant bed as well as on newly set plants and on the growing 
crop. Tests with different diluents for the derris or cuhe root powder indicated 
that Sterilized tobacco dust was the most suitable for this purpose and did not 
leave unsightly deposits on the harvested plants. 
In laboratory and held experiments in Florida and Tennessee designed to 
determine a satisfactory substitute for lead arsenate or paris green for the con- 
trol of tobacco hornworms, many different types and dilutions of Insecticides, 
Including standard insecticides as well as some of the more recently developed 
materials, were tested. No promising substitute for arsenical compounds pas 
been found, hut field experiments demonstrated that dust mixtures of paris 
green and bydrated lime, when applied properly, gave effective control of the 
hornworms and reduced to a minimum the degree of injury to the plants and 
the quantity of objectionable residues on the harvested product. 
Continued control work in Florida and Georgia against the tobacco budworm 
demonstrated that under commercial conditions this pest could he controlled 
sii cessfullj with a properly applied bait composed of lead arsenate am: 
meal. No success was obtained in attempts to substitute a cheaper carrier for 
corn meal in t he budworm bait 
i [( id and laborators tests in Florida with various Insecticides directed against 
the tobacco thrips yielded Inc lusive results. 
Under conditions of light Infestation In Kentucky and Tennessee, a poisoned 
bait containing paris green, corn meal, and oil of mirbane gave g 1 control «.f 
bworm (Crambua caliginosellua Clem.), when applied soon after 
the plant - \\ ere Bet In the held. 
\ ' of the areas In North Carolina, South Carolina, and Virginia 
flue curing is produced disclosed that the principal 
tobacco in those area* were flea beetles, hornworms, and budworma 
Btudli control of these pests In these areas were initiated during the 
