BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 
raining 8 pounds of tartar emetic and 5 gallons of molasses in 100 gallons 
of spray have caused severexmjury. Mist sprays of the same mixtures, < 
the other hand, have not caused appreciable injury. No effect on fruit com- 
position has been observed thus far. Similar experiments have been c 
ducted in the Rio Grande Valley with the cooperation of the Division of 
Mexican Fruit Fly Control, with similar results. 
Further extensive work is being carried on by the Whittier, Calif., station 
with the control of the citrus thrips (Scirtothrips citri Moulton). A number 
of materials other than sulphur are being tested this season, including dusts 
containing rotenone, zinc sulphate, pyrethrum, and zinc oxide. Tests are also 
under way with bentonite and blood albumen as stickers for sulphur dusts. 
\ The Whittier station has continued to obtain data on the biology of the 
(California red scale as a basis for a study of the resistance of this insect to- 
(fumigation with hydrocyanic acid gas. 
FRUIT FLIES 
Investigations on various fruit flies that are potential pests to fruit culture 
in the continental United States have been continued at laboratories in Hono- 
lulu, Hawaii; Mexico City, Mexico; Mayaguez, Puerto Rico; and Balboa, 
Canal Zone. 
In Honolulu studies to determine the effects of high and low temperatures 
on the immature stages of the Mediterranean fruit fly in various host fruits 
have received special attention. Hundreds of thousands of larvae and thou- 
sands of infested fruits have been used in these tests. These have centered 
around the time interval required at 31° to 32° and 108° to 112° F. Laboratory 
and field studies have also been made to determine the effect a wide variety 
of poisons may have on adults when used in sweetened sprays. Among the 
materials tested were various nicotine compounds, copper arsenite, copper tar- 
trate, copper sucrate, and certain salts of cadmium, Some of these are more 
effective than lead arsenate but none were as to^fc as tartar emeti c. Experi- 
ments to develop and determine the usefulness^ diffe*fent types of traps and 
baits in controlling and detecting the presence of adults have been continue .1. 
special attention being directed to those containing or releasing ammonia. 
At Mexico City, attention has been directed principally to baits and poisons 
for the Mexican fruit fly (Anastrepha ladens Loew) and related forms of 
Anastrepha. The studies on baits indicate that a product of the metabolism 
of yeast or other organisms presents one of the attractive principles. Copper 
compounds, particularly copper sucrate, have shown a high degree of toxicity, 
and a special study has been made of them. Attention has also been given 
to determine the host preference of various fruit flies occurring in Mexico 
and to experiments to determine the effect of climatic factors, especially low 
temperatures, on survival. Adults of both A. ludens and A. Serpent inn Wied. 
survived in outdoor air temperatures as low as 22° F., but both are killed 
when exposed to temperatures reaching a minimum of 14° for a period of 7% 
hours. A. ludens appears to be more resistant to low temperatures than does 
A. serpentina. 
At Mayaguez, Puerto Rico, the studies have been concerned with Anastrepha 
acidusa Walker and A. suspensa Loew and have consisted principally of tests 
to determine host relations and the effectiveness of various poisons and bait- 
under Puerto Rico conditions. 
- Twenty-two species of fruit flies are known to occur in the Canal Zone, ai 
work at the Balboa laboratory has been concerned principally with th< 
termination of facts on the habits and host preferences of the various sp 
PHONY PEACH DISEASE CONTROL 
The phony peach disease, a virus disease intercommunicate anion- peach, 
plum, apricot, almond, and several other species, is known to have existed in 
peach plantings in Georgia for more than 50 years. It was not. however, until 
about 1920 that serious economic damage occurred. The disease is now recog- 
nized as a potential menace to the commercial growing of peaches in this 
country. The limited amount of scouting from 1926 to 1934 showed thai the 
disease had spread to other States, and it is now known to bo wide-spread 
throughout Georgia, Alabama, Mississippi, Louisiana, eastern Texas, ami 
northern Florida, and scattered in South Carolina. Tennessee, and Arkansas. 
A few cases have been found in North Carolina, .Missouri, and Illinois, and In 
