46 THE SUGAE-BEET WIREWOEM. 
young growing beets were carefully taken into consideration, but the 
significance of these points, if there is any, is too slight to be notice- 
able. While the beetles have quite a strong flight, it was observed 
that they stay relatively near their hibernating places, so the most 
important factors at this period are the food and hibernating quarters 
which determined their presence earlier. These conclusions were 
arrived at from observations in fields aggregating several hundred 
acres. These factors, however, govern dissemination under normal 
conditions only. 
Other Factors Governing Dissemination. 
One factor which governs the direction of flight of the adults to 
some extent is the wind. This factor, however, has its limitations, 
as the beetles can fly mth ease against a very Hght breeze, and if 
the ^^ind is blomng too strongly they do not fly at all. 
The floods which are apt to occur during the time the beetles are 
in secondary hibernation, or a little later, are probably of some 
importance — at least they must be so locally, where the San Gabriel 
River spreads over many acres cf the beet fields almost every year. 
This river flows slowly and carries much rubbish, so that a large per- 
centage of the beetles carried along would probably survive. 
NATURAL CONTROL. 
Enemies and Checks to the Beetles. 
The adults of Limonius californicus, being slow in their movements 
and conspicuous, are quite subject to the attacks of predaceous ene- 
mies. The good work of these enemies is further helped by the fact 
that the fields are quite bare at the time they are present in the 
largest numbers, while the beetles are concentrated for a part of the 
time. 
Unfortunately no figures can be given regardmg the relations 
between the birds of the beet fields and the beetles, but a few observed 
facts may be given at this time. The only notes vrhich bear on the 
insectivorous habits of the birds locally were taken on examination 
of the excrement of the California shrike {Lanius ludovicianus gam- 
heli) during the month of April. This excrement was made up ahncst 
entirely of coleopterous ^v\.ng covers, and of these LiTUonius califor- 
nicus and Blapstinus sp. formed about 90 to 95 per cent. A very 
reasonable estimate would be that at least 70 to 80 per cent of the 
excrement examined was composed of fragments of Limonius cali- 
fornicus. 
Many observers have determined the fact that nearly all insectivo- 
rous birds eat different species of Elateridse readily, as the latter do 
not seem to be in the least distasteful to them. Following is a partial 
