66 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 194 
Sl S( KPTIHII.ITV TESTS, NURSERY INSPECTION, AM) IDENTIFICATION 
Tests to determine resistance or susceptibility of the many existing 
species of barberry to stem nisi were continued under greenhouse con- 
ditions at the University Farm, St. Paul, Minn. Fifty-six different 
barberries, including !) hybrids, were inoculated during the year, com- 
prising G."> series of plantings. Each scries consisted of \ or 5 plants 
of the species under test, pins 1 plant known to be susceptible. Of the 
C>3 series tested, infection occurred in varying degrees in 58. No new 
species were added to the susceptible list, as these results merely cor- 
roborated those obtained in the outdoor garden at Bell. Md. Ii is ex- 
pected, however, that 41 species will be added to the susceptible list 
and u* species to the resistant or immune list, after they are checked 
taxonomically. 
During the summer of 1939 requests for inspection were received 
from 49 nurserymen and 1 seed house. As a result of these requests,, 
together with the cooperation of State leaders in charge of barberry- 
eradication work in several States, a total of 13.214 barberries were 
removed from nurseries and private home sites on the nursery grounds. 
Forty-four nurseries received permits to ship immune species of 
Berberh and Mahonia into or between States comprising the eradica- 
tion area. 
More than 125 specimens taken from barberry and mahonia plants 
were received for identification, and 40 additional specimens were 
identified and filed. Forty-five packets of barberry seed received from 
China during the year were stratified and planted. These are all 
numbered, and will be identified as soon as corresponding herbarium 
specimens are made available. 
TRUCK CROP AM) GARDEN INSEC T INVESTIGATIONS 
Tn this field of research the more important practical applications 
of 1 1 10 results obtained were concerned with the control of the tomato 
fruitworm in southern California and Utah, of the pea weevil in the 
Northwest, of cabbage caterpillars as they affect cabbage grown in 
South Carolina, and of the tobacco flea beetle on flue-cured tobacco 
in North and South Carolina. 
A survey of tobacco growers' pack houses for the tobacco moth in 
North Carolina, South Carolina, Virginia, and Georgia was com- 
pleted and showed that the insect may develop into an important pest 
in pack houses in North Carolina and Virginia. Heretofore it lias 
been known only as a pest in stored tobacco. 
The work on the sweetpotato weevil yielded additional valuable 
information on the survival of the insect under variable seasonal con- 
dition-, its ability to disperse by flight, and its seasonal habits, which 
can be used in the prosecution of an eradication program. In this 
study was included an extensive survey of the wild plants upon which 
iht' weevil may survive for Limited periods, or thrive and serve as 
reservoirs of infestation of the cultivated sweetpotatoes. 
Wireworms, both in the irrigated lands of the Northwest and in 
California, continued to be important problems. Early experiments 
with dichloroethy] ether as a soil fumiganl against them showed con- 
siderable promise. More recent tc-ts, however, seemed to indicate- 
