46 ANNUAL REPORTS 01 DEPARTMENT 01 AGRICUI/TURB, 1 
also is believed to have been responsible for a reduction in injuries by 
the oriental fruit moth in commercial peach orchards. Mact\ 
Rohw. was the principal parasite, although five other 
• involved. 
Ladybird Beetles Withstand DDT Sprays 
I . dybird beetles-jpredators of mites on apples in the Yakima, Wa 
area, recovered sufficiently after two DDx sprays to effect adequate 
control of the mites during the Latter part oi the season. The study 
showed for the Erst time that beneficial insects are effective in 
trolling mites after spraying with I > I > T. 
Progress Wade Toward Eradication of Hall Scale 
Progress toward tin' eradical ion of Hall scale from the limited 
California where it has been found continued. No living scale was 
found during the inspection of an isolated infestation at Oroville. 
A- this infestation ha- now received three fumigations, it ha- been 
dropped from the fumigation schedule, hut will be reinspected from 
m time. All trees known to have scale <>n them have beej 
d from the infested area at Davis. In the main area near Chico 
intensive inspection revealed the presence of -'"111' on four additional 
properties, involving about 700 trees. All the properties are within 
the area known to be infested. Severe weather in the winter of L95 
and unusually early development of tin- trees in the spring interfered 
with the fumigation program. Approximately l. ,M trees were fumi- 
I. L,280 01 them for the third and last time unless live scales re- 
appear on them. Tin- rest received their first or second fumigation. 
A hoi it 2,000 1 rees remained 111 .treated. All trees left on the treatment 
schedule were sprayed to retard spread of scales. 
Frosl in Texas Groves Makes Control Measures igainsl Mexican 
Fruit Fly Unnecessary 
freezing weather for several days late in January 1951 
isly curtailed the production of citrus fruit in Texas gn 
I second consecutive year that the groves had 1 erely 
8 ; 1 of the fruit remaining on the trees was damaged to 
such an extent that it could not he shipped a- fresh fruit. The trees 
themselv) \ large number of young tree- not 
1 • 1 \ banked were killed outright. Most of the older trees, weak- 
'm\ previous cold weather, were either killed outright or wei 
rely damaged that many 01 them will be removed. Lo\^ tempera- 
tures struck just as control activities against the Mexican fruit Ely 
ell under way. [nspections throughout the earlier 
of the year had indicated that the fruit flies were beginning to 
build u|> and that the annual migration from M \ was in prog 
No infested fruit had been found and no sterilization activities were 
undei it the time of the freeze, I e ti • that remained in the 
nade rai her sl< to\* ard n coi ery, ov< b 
unusual drought. By the beginning of summer indications were that 
many old trees and a large number of young banked trees had sun 
wit h f< >: :i small fi u:i crop. 
