8 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 1940 
to the adult in the insectary from pecan foliage. Approximately 
50 percent of the larvae included in the teste readied the adult stage. 
The Kupene. ()re<r., laboratory made additional collections to deter- 
mine the distribution of the filbert worm (Melissopus latiferreamu 
Wals.). formerly referred to as the Catalina cherry moth. These 
Burveys indicated the presence of the uised at leas( 200 miles inland 
from the Pacific Ocean, and al elevations ranging up to 3,600 feet. 
Some of the larvae of this species were found t<> carry over through 
a second winter before emerging as adults. Nearly a dozen ^ j >o< • i*-> 
of parasitic wasps and flies were reared from the filbert worm or from 
materia] containing chiefly the filbert worm. 
DRIED-FRUIT INSECTS 
Following up the observations of a year ago that the saw-toothed 
grain beetle, a major storage pesl of dried fruit-, does not fly to any 
extent, tin 1 Fresno. Calif., laboratory began ail experiment t«> deter- 
mine the protection from crawling insects that might be afforded 
cleaned stored raisins by surrounding the stacks of boxes at the 
ground level with a trough barrier filled with crank-case oil. 
A review of the results to date of experiments with cold storage for 
the control of dried-fruit insects indicates that the time-temperature 
combinations that may be expected to be lethal will be found to be in 
the neighborhood of the following figures: Saw-toothed grain beetle 
adults. 32° F. for less than 27 days. 3G° for le>s than 28 days; saw- 
toothed grain beetle larvae, 32° for less than 15 days. B6° for less than 
20 days: Indian-meal moth larvae. 32° for less than 28 days, 36° for 
less than 50 days; raisin moth larvae, 32° for more than 100 days, 
36° for more than 115 days. 
A field study of the causes of spoilage of maturing grapes in the 
vineyard showed that the raisin moth is a minor factor. The pres- 
ence of grapes damaged by other eauses. however, aids the build-up 
of raisin moth infestation. 
SUBTROPICAL FRUIT INSECTS 
The intensive laboratory work with the factors influencing the re- 
sults of cyanide fumigation against the California red scale was 
continued at the Whittier, Calif., laboratory. With a range of tem- 
peratures from 50° to 77° F., higher mortality of the st ale was se- 
cured at the lower temperatures. The influence of temperature was 
more pronounced in the second molt, stage than in the mature stage, 
and in the resistant strain than in the nonresistant . 
In comparative tests with the two strains of the California red 
scale maintained in the laboratory for a number of years, it was 
found that although these strains reacted similarly to pre and post- 
conditioning and protective stupefaction, the reaction- of the resis- 
tant -train were more pronounced. The resistant -train was appar 
ently more sensitive t<> temperature changes and preliminary l<>w 
dosages of hydrocyanic acid pas. 
Experiments carried on at Whittier with the use of toxicant- in 
oil for the control of the California red scale confirmed those of last 
year and indicated that extracts from the rotenone-containing plants 
are more pr<»nii-ii!L r toxicants t han nicotine. 1 he nio-t effect ive com- 
