')() AXXl'AL KKPOHT> OK DKPARTM KNT OF A< ' I" I/IT UK. 1940 
more than 7 months after baling. Experimental fumigation of 
baled alfalfa hay with methyl bromide, partially in cooperation with 
Oregon State workers, established the fact thai a complete kill 
could he. obtained with a dosage of 1 pound per l.ooo cubic feed of 
space in a gastighl chamber at temperatures of 50° F. or higher. 
A complete year'- observations on the weevil Hypera brwmei- 
permis (Boh.), first discovered Last year infesting legumes at Yuma. 
Ariz., indicate that it has only one generation a year and that ap- 
parently it prefers clovers of the genus Melilotus to alfalfa as a 
food plant. The adults remained hidden and inactive throughout the 
summer, emerged gradually, mated late in November and in Decem- 
ber, and laid eggs mainly in small dead stems of litter on the soil 
surface or in voimir green stems of souTclover during January. 
February, and March. The larvae of the new brood were mostly 
full-grown by early spring and had practically all changed to the 
adtdt stage by the end of April. Larval mortality was high, and 
fewer adults appeared in the spring of 11)40 than in 1939. Most of 
these had gone into hiding for the summer by mid-May. Several 
species of parasites were reared, but the percentage of parasit iza- 
tion was low. 
The breeding of alfalfa resistant to the pea aphid was continued 
in 11>:W with lines derived from the work of 1938. The F 4 seed* 
lings tested were the progeny of 56 selfed F :i plants representing 
10 aphid-resistant families. Of the more than 1,000 F 4 plants tested 
from these families only 2 showed an infestation of aphids. These 
tests indicated that 8 of the resistant families tested retained com* 
plete resistance and are probably homozygous!? resistant to the pea 
aphid. In field test> of resistant and susceptible plants the resistant 
plants remained remarkably free of aphids. Their maximum plant 
infestation never exceeded 22 percent, whereas susceptible plants 
were 100 percent infested. In similar breeding operations at Man- 
hattan, Kans.. mass testing of alfalfa seedlings revealed individual 
plants upon which aphids declined to feed. Testing of such plants in 
cages confirmed this observation. As climatic conditions were un- 
favorable for open-field testing, cage testing was successfully used. 
Selections were made from resistant plants for further experiments 
in 1940. 
A large-scale experiment for the control of Lygtu spp. attack- 
ing the alfalfa seed crop in the field was conducted in the Mohawk- 
Valley of Arizona in cooperation with the Arizona Extension Serv- 
ice. The procedure consisted of late winter clean-tip of all grow- 
ing alfalfa and cutting the first hay crop and starting the seed crop 
at approximately the same time in all fields. This experiment re- 
sulted in greatly decreased numbers of Lygw and subsequent l«>w 
percentages of injured; seed. Although this represents only one 
Season's trial, there is reason to believe that where community action 
is hilly obtainable this system of control may prove substantially 
successful. 
With the discovery in L938 of the vetch bruchid in the vetch seed- 
producing and shipping areas of western Oregon and Washington 
as well as m 'he Atlantic States, the need of additional information 
on effective fumigants for treatment of infested seed became more 
urgent. Satisfactory do-ai_ r e- of methyl bromide and chloropicrin 
b»r in j_ r a^tight chamber- were therefore worked OUl and pub- 
