ae ee 
In regard to termite control, Mr. Zetek states: "It is very 
gratifying to note that the Panama Canal (Administration) has followed up 
the recommendations * * * and that the present method of building con— 
struction affords almost perfect protection against these pests, and this 
without any significant increase in cost." 
The distribution of Eretmocerus serius Silv., the parasite of the 
citrus black fly recently introduced into Cuba, hag been carried on ex-— 
tensively during the past month. It is now well distributed throughout 
the island and commercial control has been effected on the groves which 
received the earlier liberations. A number of colonies have also been 
forwarded to the Canal Zone and to Haiti. The Ccoccinellid beetle Cryp— 
tognatha sp., also introduced from Malaya, is occasionally fully as effec— 
tive as the parasite, though in most of the groves it fails to increase 
sufficiently to have any appreciable effect upon the black fly popula— 
iALRth s 
C. C. Plummer, Cuernavaca, Morelos, Mex., who is conducting pre— 
liminary experiments on the hydrogen-ion concentration of soils in con— 
nection with his work on the Mexican fruit worms, reports: "August was 
a month particularly favorable for such studies, because of the numerous 
dried or rotten mangoes found lying on the ground or buried in pits. 
It is believed that if the pH of the soil does change during the year 
it is lower in August and September than it is during any other months 
of the year." Mr. Plummer submits data procured from 12 soil samples 
taken from different places, with the following conclusions: "It is 
interesting to note the slight variability in the hydrogen-ion concentra-— 
tion of the soil taken from different places. These samples were all 
taken from the most diverse situations the writer was able to find in 
this garden." 
In order to determine the effect of the heat from the sun in de— 
stroying larvae of the Mediterranean fruit fly, A. C. Mason, Honolulu, 
T. H., placed four collections of infested fruit in direct sunlight. He 
reports: "The temperature on the inside of the fruits registered from 
100° to 110° for several hours each day. Seventy-two mangoes produced 
an average of 0.2 pupa per fruit after being in the sun ten days, while 
the check lot kept in the insectary produced an average of 2.3 pupae per 
fruit. Similarly treated star apples produced an average of 1.2 pupae 
per fruit, and the check lot 1.8; treated kamani nuts yielded 2.57 pupae, 
and untreated 5.88 pupae; treated rose apples gave 3.5 pupae, and un— 
treated 13 pupae per fruit. Normally the fallen fruits are not usually 
exposed to direct sunlight for long periods at a time. These experiments 
show that a high percentage of the larvae are killed when this happens.” 
Continuing experiments in vapor—sterilization of fruits at the 
Honolulu laboratory, 0. C. McBride reports: "Four lots of avocados of 
the variety Wishards were treated in the high-temperature room. Injury 
to the fruit is noted after three hours of heating. Firm fruit picked 
from the tree appears to withstand the heat treatment much bette: than 
Tipe fruit. The variety Wishards has a good (Mediterranean fruit fly) 
infestation. We have secured 100 per cent control of the fruit fly larvae 
at temperature 110° F. for eight hours. Apparently larvae are killed 
more readily in avocados than in citrus fruits. Avocados subjected to 
freezing temperatures break down quickly on removal to room temperatures." 
