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over paints applied in March, April, and May, gave 100 per cent woolly 
aphid control throughout the remainder of the season; (5) each of the 
paints giving satisfactory woolly aphid control had nicotine sulphate 
incorporated in it; (6) woolly aphid colonization, particularly in cleaned 
but unpainted check cankers, became apparent early in May, by early 
June from 25 to 50 per cent of the checks were infested; (7) there seems 
to have been practically no change in the number of cankers infested 
after the mid-October examination." 
"Inability to determine the sex of Conotrachelus nenuphar Herbst 
adults without dissection has handicapped certain phases of biological 
studies by workers at this and a number of other laboratories," writes 
Oliver I. Snapp, Fort Valley, Ga. "Therefore work was started (by Mr. 
Snapp and J. R. Thomson) during the month (December) to determine, if 
possible, a methcd by which the males and females could be distinguished 
accurately and easily without dissection. * * * The only noticeable 
differences in the external anatomy of the male and female found thus 
far is an enlarged tibial spur of the metathoracic leg of the male and 
a difference in the shape of the supra—anal plates." 
A. C. Mason, of the Mediterranean fruit-fly project, Honolulu, 
T. H., submits a summary of the effect of elevation on the infestation 
of guavas by the fruit fly. He says: "By elevation here is meant all 
the environmental factors at the varying altitudes. Temperature, no 
doubt, is the most important single factor, but rainfall and other fac— 
tors have an influence. * * * It will be noted that infestation var- 
ies from 68.7 per cent in fruits growing at less than 500 feet eleva— 
tion to 28.1 per cent in fruits collected at 2,000 feet elevation. . The 
percentage of infestation and also the average number of larvae per in- 
fested fruit decrease in direct proportion to the increase in elevation." 
Mr. Mason and C. B. Keck recently inaugurated a series of feed-— 
ing experiments at the Honolulu laboratory to ‘determine the nature of 
the food fruit flies obtain from citrus, mango, and guava trees when 
no host fruits are present. "Adult flies have been maintained alive 
for 30 days in cages when given only leaves (changed daily) and dis- 
tilled water. We have also shown that they can maintain themselves 
much longer when old, dirty, and sooty leaves are given them than when the 
leaves are fresh and clean. All the flies died in two days when the 
leaves were washed before being fed to them, giving the same results 
as for the checks, which were given water only. The data to date (Dec— 
cember) indicate that the adult flies are living on honeydew excretions 
from scale and other insects on the trees. Since the citrus trees are 
well covered with these excretions and the resulting growth of sooty 
mold, this may account for the attraction of the flies to the citrus 
trees. Such a conclusion may offer an explanation as to why the flies 
remained in the citrus trees in Florida, resulting in the success of the 
poisoning campaign." 
