4S AXM'AI. KE PORTS OP DEPARTMENT OF AGRICULTURE, 1939 
as injurious in the Pacific Northwest as in North Carolina, it may 
become necessary to discontinue the culture of susceptible varieties 
and substitute therefor such varieties as are immune to the attacks of 
the insect. Methods of fumigating seed for safe shipment are being 
studied. 
INSECTS ATTA< KING -MAIL CHAINS 
For several years the work of breeding wheats resistant to attack 
by ilif bessian fly has been progressing steadily. In L938 the fly- 
resistant characteristics of Dawson wheal bad been successfully t] 
mitted, through the fourth back crosses, to Poso and Big Club for the 
production of commercially desirable fly-resistant wheat for use under 
California conditions. It is now believed that this work may be 
completed in l'-»l I. 
S imil ar work in the production of fly-resistant wheats for culture 
in the soft red wheat areas has progressed well. In an experimental 
nursery at La Payette, [nd., containing L 00,000 consistently resistant 
segregates, the resistant lines as a whole retained a greater plant vigor 
and more definite tendency to tiller than was the case with lines sus- 
ceptible to fly attack. Other experiments indicated that fly-infested 
wheat plant- are more susceptible to winter-killing than uninfi 
plant-. 
INSECTS ATTACKING SUGARCANE 
It is estimated that the sugarcane borer, which is one of the princi- 
pal limiting factors in the production of cane sugar in Louisiana, 
caused losses amounting to $4,700,000 in L938. According to recent 
experimental work in the control of this insect by sprays containing 
cryolite, both the natural and synthetic forms of this chemical give 
approximately D0-percent control. 
INSECTS AFFECTING STORED GRAINS 
A study of the condition of farm-stored grains in relation to insect 
infestation thereof, made in r.»."> s . resulted in the publication in Octo- 
ber of that year of Farmers' Bulletin L811, Control of [nsects Attack- 
ing Grain in Farm Storage. It contain- direction- for tin' simple 
fumigat ion of such grains under farm condit ions, together with direc- 
tions for the proper farm storage of such grains. A survey was made 
of ripening grains in various pari- of Kansas, Missouri, Oklahoma, 
and Texas to determine to what extent these grains became infested 
by insect pest- of stored grain prior to harvest. A- a result, 21 differ- 
ent species of insects were reared from wheat heads gathered in the 
States mentioned. In southwestern Missouri the rice weevil was found 
infesting corn in 50 percent of the cornfields examined, but in Kan- 
sas only a few widely scattered iield- were found to h" infested. Sur- 
veys indicated that Losses in farm-stored grain would he much heavier 
in L938 than for some years previous. 
The somewhat general use of chloropicrin gas for the fumigation of 
grain in storage had raised the question of the possible unfavorable 
• j]'-'! of such fumigation on the germination of wheat. A recent 
investigation of this subject has shown that the viability of wheat 
containing 1 1 to L6 percent of moisture is seriously injured when 
exposed t<> a dosage of 6 pound- of chloropicrin to l.ixio bushels of 
