58 ANNUAL REPORTS OB DEPABTMEN1 OF AGRICULTURE, 1 
TRUCK CROP AND GARDEN INSEt l [NVESTIGATIONS 
TOM kTO I R1 ITW ORM 
In the summer and fall of L988 the investigations on the tomato 
fruitworm were continued on a comparatively Large scale in Cali- 
fornia, Utah, and southern [ndiana, and the following discussion 
applies to the results obtained during that period. During the course 
oi these investigations a series of experimental tests were performed 
with materials containing rotenone. particularly derris and cube, and 
with phenothiazine, cuprous cyanide, copper arsenate, copper cyana- 
n i id*', cryolite, calcium arsenate, and several other materials. All these 
insecticides, except those containing rotenone, were of some ralue in 
reducing injury done by the tomato fruitworm, but cryolite and cal- 
cium arsenate gave the best results. While the degree of crop protec- 
tion attained by using cryolite and calcium arsenate in dust mixtures, 
spray mixtures, and poisoned baits varied considerably in different 
seasons and on different farms, the indication- were that the best yield 
of uninjured fruit was obtained when a cryolite-dust mixturcLcontain- 
ing 70 parts by weight of cryolite and 30 part- of talc was \\-*'<\. In 
these tests natural cryolite which contained approximately 90 percent 
of sodium fluoaluminate and one brand of synthetic cryolite con 
taming approximately 98 percent and another containing approxi- 
mately ^:'> pi rcent of -odium fluoaluminate were employed. In 
replicated experiments on several varieties of tomatoes and in several 
different fields the application of the cryolite-dust mixture- resulted 
in ;i degree of control which ranged from 30 to ( .h> percent. These 
figures are based on the percentage of fruits damaged by the fruit worm 
in treated plot- a- compared with the percentage damaged in plots 
that were either dusted with a cube dust mixture of left undusted. 
Some of the che.k plots in the fields where these experiments were 
performed were threatened by the tomato pinworm, and in order to 
prevent serious loss to the grower from this source applications of 
cul>e dust were made, as this materia] was known to he partly effec- 
tive against ilii- insect, hut would not affect the tomato fruitworm; 
consequently the application of these cube dusts did not seriously 
affect the results of insecticidal tests against the tomato fruitworm. 
Three brands of calcium arsenate were w^^\ and these gave control 
ranging from 30 to 64 percent on the same basis of comparison as 
stated previously. It will he noted, therefore, that calcium arsenate 
was slightly inferior to cryolite although in laboratory tests it ap- 
peared that the former material was as toxic to quarter-grown Larvae 
of t lie fruit worm a- was cryolite. 
The highest degree of tomato fruitworm control was achieved with 
cryolite-Oust mixture- when three applications were made at '2-week 
intervals, beginning when the foliage of the tomato plant was about 
1 loot in diameter. In California, where on an average an acre of 
tomatoes contained LOO0 plants, approximately L0 pound- of the dust 
mixtures was used for the first application. *J<> for the second, and 
30 for the third, per acre. Both power dusters and fan type hand 
dusters were used to apply the material.-, and the plants were du-tcd 
from both sides at cadi application. A special attempt was made to 
cover all the foliage, since extensive biological observations have 
