THE CLOVER ROOT BORER 35 
Chapman (6) on Ulex europaeus; Cecconi (4, p. 160) on Cytisus alpinus; 
and del Guercio (16, p. 264) on Cytisus laburnum. Bedel (2) found. 
it also on an old, woody root of Ononis natriz, exposed on the side 
of a bank. Some of the records on Cytisus may refer to Hylastinus 
fankhauseri Reitter (36, p. 250) rather than H. obscurus, but are re- 
tained here for reasons stated on page 3. , 
DAMAGE 
FIRST CROP YEAR 
The earliest injury to new clover (first crop, seeded the previous 
year) is observed in the spring a week or two after the time of the 
first migratory flight. The females at this time are busily engaged in 
making the first egg galleries, and the males are feeding, usually in 
grooves on the crowns. The simultaneous attack of five or six root 
borers on one small root often girdles it, causing wilting and early 
an of the plant. This injury first appears late in April or in 
ay. 
(pene disease, caused by Sclerotinia trifoliorum Erik. (14), is prev- 
alent at this season, and in the Pacific Northwest for several months 
preceding, and may easily be mistaken for this njury. Injury caused 
by this fungus differs from root-borer injury in that the several stems 
of the diseased clover plant usually wilt at different times. Often a 
few stalks of the plant remain normal, while infected stalks are stunted 
and killed back to the crown. In the case of injury by root borers 
all the stems of the plant usually wilt at thesame time. An examin- 
ation of plants affected by the fungus will also show discoloration of 
the stems and often, on dead stalks, a thin whitish fungous growth. 
* In new clover no further injury is usually noted until haying time, 
when, in case of severely attacked fields, many plants are broken off 
at the crowns by the mower. This is often the first injury observed. 
Toward the end of July, when the new second growth is well up, a 
severely infested field shows many sickly and dead plants and the | 
seed of ripe heads is often withered and light. In one case observed 
a 5-acre field of clover in its first crop year had been destroyed by 
the end of July, 1914. Early the next spring the ground was bare 
except for weeds and the dried dead stems of thesecond hay crop, which 
had not been worth cutting. At this time the clover roots in this 
field had been almost completely consumed by the borers; the dried 
stems had fallen or were sticking out of the ground, attached to 
small pieces of clover crowns which the hordes of borers were rapidly 
consuming. This severe and unusual damage was attributed to the 
fact that a 40-acre field of old clover about one-quarter of a mile 
away had been plowed in April, 1914, and borers leaving this field in 
large numbers had migrated and concentrated on this small field 
with fatal results. A similar case was noted by Davis (9, p. 47) in 
July, 1893, the clover being of the mammoth variety. Cases of 
complete destruction of a clover stand have also been reported from 
the States of Indiana, Ohio, and New York. Severe injury to red 
clover in the first crop year is likely to occur whenever near-by fields 
of old clover are plowed in the spring. 
Usually, however, the injury to young clover consists of a gradual 
dying of the plants during July, August, and September. The plants 
that are most severely infested and die first (in July) set light and 
