64 THE SUGAE-BEET WIREWORM. 
Considering that all the growers have idle horses during the late fall, 
the plowing would not appear to be a large item of expense, espe- 
cially when its value to the soil is taken into consideration. 
In conclusion it may be safely stated that the clean-culture remedy, 
especially when reenforced by fall plowing and early planting, is easily 
the most promising remedy which has thus far come under observa- 
tion during the sugar-beet wire worm investigations. 
SUMMARY. 
(1) The sugar-beet wireworm kills the beet plant by injuring the 
root. It is most injurious while the beets are young and is destructive 
only in the wireworm or larval stage. 
(2) The life cycle probably covers four years. About one month 
each is required for the egg and pupal stages; seven to nine months 
for the adult stage, diu-ing the greater part of which the beetle is in 
hibernation; and about three years, or the rest of the time, for the 
larval stage. 
(3) Thus far it seems to be impractical to employ remedies against 
the larvas. As these live underground and are protected by a thick 
integument it is difficult to injure them. They also seem able to eat 
a certain quantity of many poisons and deterrent substances with 
safety. 
(4) Plowing in the fall is a fair remedy against the pupse, but at 
that time of the year the soil is dry in southern California and is 
turned up in large clods; consequently many pupae escape destruction. 
(5) Much of the injury to the beets may be avoided by early 
planting, thus giving the roots a good start before the wireworms 
are doing their most extensive feeding. 
(6) Clean culture against the adults, by compelKng them to seek 
shelter elsewhere and exposing them to the attacks of their bird 
enemies, seems to be the most practical remedy found thus far for 
this insect. The efficiency of this remedy would be increased if fall 
plowing and early planting were used with it. 
BIBLIOGRAPHY. 
1843. Mannerheim, G. G. von.— Bull. Soc. Imp. Nat. Moscou, vol. 16, p. 283, 1843. 
Original description of Limonius calif ornicus under the name 
Cardiophorus caUfornicus. 
1912. Vaile, R. S. — Aim. Rept. Hort. Comm. Ventura County, 1912. 
Brief account of damages, and remedies proposed for experiment. 
