38 BULLETIN 1426, U. S. DEPARTMENT OF AGRICULTURE 
INJURY TO SEEDLING CLOVER 
It has been commonly stated by entomologists and others that 
clover roots of less than a year’s growth are not attacked by root 
borers. <A field near Lebanon, Oreg., was seeded in April, 1915, to 
red clover, with a thin stand of oats as a nurse crop. When observed 
August 10, following, the clover had been noticeably damaged by 
clover root borers. The clover plants at that time were 12 to 14 
inches high, and blossoming. The roots were less than one-fourth 
of an inch in diameter at the crowns. One larva, almost mature, was 
seen, indicating that development would be sucessful on some of these 
roots. An old clover field located across the road had been plowed 
in March. These two fields were in a long, narrow valley, bounded 
by wooded hills and crossed at intervals by small groves of trees, and 
the nearest other clover field was distant a mile up the valley. Root 
borers apparently had been forced to attack the young clover when 
the old roots of the plowed field dried out and the roadside clover in 
the vicinity had been killed. In another case 1 root in 20 was found 
infested by root borers June 10, 1918, in a field seeded in November, 
1917. Young seedlings in old fields are not uncommonly attacked 
by adult root borers. 
NATURAL ENEMIES 
Very few natural enemies of the clover root borer are recorded in 
literature. Riley (37) recorded a soldier beetle larva, probably ( Tele- 
horus) Cantharis bilineatus Say, as predacious on the clover root 
baton H. L. Parker has reared the soldier beetle, Chauliognathus 
pennsylvanicus DeG."! from ‘black velvety” larve which ate root 
borer larvee. Adults were reared from ‘white slender naked pup 
slightly over one-half inch long’ on November 18, 1914, and April 
27, 1915. 
In the Pacific Northwest the only natural enemy observed to 
attack the borers in the roots and on the ground was a fungous 
disease caused by the well-known entomogenous fungus (Sporotr- 
chum) Beauveria globulifera Speg., as determined by the writer. This 
fungus attacks many ground-frequenting insects, whose spore-covered 
bodies are commonly found in clover fields. Root-borer adults are 
exposed to infection while above ground, moving from root to root, 
mating, and starting burrows. They are less likely to become infected 
while in mines in the root. This disease is most prevalent in the fall 
and spring, and any reduction in the number of root borers at this 
time, prior to the breeding period, is of economic importance. Larvee 
and pupe in mines in the roots are occasionally attacked by the same 
fungous disease. It appears to be very prevalent on low, wet, poorly 
drained land, and there are also indications that root borers on less- 
favored host plants are especially susceptible to the infection. The 
disease is certainly parasitic, as the cylindrical conidia and short sec- 
tions of hyphe have been found in the blood of living borers. 
An attempt was made in April and May, 1920, to find bird enemies 
of the clover root borer at Forest Grove. Only those birds were 
killed, 53 in all and of 22 species, which were found near clover fields 
on days when it was known that the root borers were migrating by — 
flight. On examination of their stomachs, 39 root borers were found 
11 Determined by J. A. Hyslop. 
