]() WMAI. REPORTS 01 DEPARTMENT OF AGRICULTURE, 1 
virtual cleanup with five applications and without tree injury. Speed- 
sprayer tests showed thai an application of the xylene-kerosene-DDT 
formula followed in 30 days by an application of an oil-cube formula 
was better than the reverse order previously used. Using the oil for- 
mula lasl also cut down the buildup of scale. Experiments showed 
that formulae with DDT or parathion arc most effective at the peak 
of adult emergence, the oil-cube formula 1 month Later; hence the 
reversal of the previous system. 
ORIENTAL FRUIT FLY INVESTIGATED 
Bioclimatic cabinets furnish valuable information on oriental fruit 
fly behavior 
>f\r]\ walk-in type cabinet- for the study of the effect of climatic 
condition- on the oriental fruit fly are now in operation in Honolulu. 
This study is being carried on jointly by the Bureau and the Univer- 
sity of California Agricultural Experiment Station. 
Each cabinet provide- an interior working space measuring 6 x G x G 
feet and is capable of cont rolling temperature through a range of from 
— 5° to 125 c F. with an accuracy of plus or minus 1° F. Relative 
humidity in 6 of the cabinets can be controlled through a range of 
from 20 to ( .C> percent at temperature- from 35° to 125 c F. : in the 
seventh humidity can be controlled .n subfreezing temperature-. Ul- 
traviolet and infrared lights simulate very closely the radiant energy 
and natural light of the sun. Flies are contained in globular screen 
3. Adult (lie- have access t<> synthetic materials and natural 
food to assure development of sexual maturity and for maximum pro- 
ductivity, fertility, and length of life. Daily mortality count- are 
made. 
Temperature and humidity conditions representat ive of the climates 
of Oceanside, Fresno, and Riverside, Calif.: Charleston, S. ('.: Fort 
Pierce, Fla.; ami Vincennes, End., were simulated in the initial cabi- 
net st iidies. 
Results of 1 year of continuous operat ion of the cabinets -how that 
the lowest average temperature at which tin- eggs or larvae of the 
oriental fruit fly can develop is about 57 F.,that average temperatures 
above 70 are necessary \'<>v the fly to attain sexual maturity without 
the preoviposition period becoming unduly extended, and that areas 
with twilight temperatures lower than <'>o may impose limitations 
on the mating of the oriental fruit fly which usually copulate- only 
at dusk. Temperature at which the fruit fly was able to reproduce 
efficiently ranged from 65 t<» s(l . It was learned that the growth 
of I he fruit fly was more rapid w hen subjected to fluctuating tempera- 
tures than in constant temperatures. Fruit flies were able to survive 
and reproduce for at least part of a year"- climatic cycle corresponding 
to t hut of each of t he local i I ies simulated. 
Tiie Vmcennes climate provided the shortest period favorable for 
laying and reproduction and consequently it was the least ac- 
ceptable climate \'<>v fruit fly establishment. The length of the period 
favorable for reproduction during the simulated year was progres- 
sively longer in the cabinets representing conditions at Riverside, 
Oceanside, Fresno, Charleston, and Fort Pierce, In comparison 
