The Hawaiian gazette. [volume] (Honolulu [Oahu, Hawaii]) 1865-1918, 1916-11-24
REFRIGERATION
CONTROLS PESTS
Mediterranean Fruit-fIy Expert
ments of Back and Pemberton
Worth Money To- Hawaii

Few realize the comprehensive char
actcr of the work done here by DR.. +.
A. Back and his assistant, c. +. Penn
berton. in their experiments on the life
history and control of the Mediterran-
can huit-6y. Hence, while not imme-
diately concerning The sugar industry,
resume of some of Doctor Backs
findings are not out of place in these
columns.
Some of these results are published
in recent number of the journal of
Agricultural Research, the official organ
of the department of agriculture at
Washington, covering determinations Of
the effect of various temperatures used
in commercial cold storage plants upon
the pupa Of the Mediterranean fruit
fly.
In the introduction the author calls
attention TO the fact that while the
greatest danger in the spread of this
pest from one country to another lies
in the transportation of the larvae
within the fruits, il is possible that tho
pest may be carried in the pupal stage
and arrive at destination in a condition
to produce infestatiOu. 1t is stated
that nearly all the experimental work
with temperatures lower than forty
five degrees Fahrenheit was carried on
IN thoroughly modern cold storage
plant here in Honolulu.
Experiments Exhaustive
"Pheir observations, made on 173 ,3lS
pupae, indicate that none survived re-
frieeration. "About fifty degrees Is
the critical point below which develop
ment can not take place and below
which death will follow if refrigeration
is continued sufficiently long" In part
they state: "At forty nine to fifty.
| one degrees only nine out of $4,000
pnpae yielded adults in refrigeration
twenty to fOrty-seven days after the in
| ward date, while three out of six held
at ffty two to ifty-six degrees yielded
adults in refrigeration thirty.eight TO
| lfty-two days after the inward date.
| Mnny pupac can complete their Cntlre
development in refrigeration at fifty,
four TO flftyseven degrees, while higher
temperatures, not considered here, mere.
iy retnrd development without causing
noticeable mortality
Pupac cannot withstand tempera-
lures below fifty degrees for prolonged
periods of time, Only three and one
pupa survived refrigeration for eight
and nine days respectively, at thirty.
two degrees, while not one Of 1900
puPae survived ten days ar this TEN.
perature. Refrigeration at a tempern.
ture averaging thirty four degrees, but
ranging from thirty.three to thirty-six,
proved fatal after the seventeenth day;
6Ol7 pupae refrigerated at this TEN.
Pcrature from eighteen to twenty-five
days Yielded no adults. while the num-
| ~ Tn oil l,.IN.
f"r fourteen to seventeen days was very
small
Low Temperatures Fatal
Ma purae survived refrigeration at
twenty eight to forty degrees, but aver.
aging thirty. six degrees. for more than
ten drNs. temperature of thirty.
eight to forty degrees proved fatal
after the nineteenth day; 3O.73l pupa
refrigerated for from twenty-one to
thirty,fVe days failed to yield adults on
removal TO normal temperatures. After
refrigeration from forty to forty five
degrees pupae from each of two lots re-
moved after refrigeration for twenty
-FOUR TO twenty seven days. respective
Yi"ldcd adults; 900 pupae removed after
refrigeration from thirty one to thirty.
four lays proved to be dead"
One Of Doctor Backs conclusions
was that cit does not seem safe to con.
ciude that the age of the pupa has
direct bearing upon it's ability to with
stand the more ordinary ranges Of cold
storage temperatures "
The results above noted Indicate that
there is an opening for the development
OF frosh fruit and vegetable export
business from Hawaii in such products
as can be held three weeks in cold stor-
age at temperatures upder forty do,
grees.
This report also shows the extremely
Painstaking and methodical manner in
which the United States department OF
agriculture experts are willing to iuves.
tigate Hawaiian problems when called
upon TO do so. ". rf