THE CLOVER ROOT BORER 21 
first. They may run parallel with the longitudinal axis of the root 
or at right angles to it or occasionally there is a combination of both. 
Maternal galleries are sometimes spiral grooves almost girdling small 
roots. Occasionally, especially in the case of a root crowded with 
borers, the egg gallery runs into the center of the stem above ground 
and eggs are laid in the pith. 
A root borer was observed starting its burrow on an exposed root 
in the laboratory. When first noticed it had dug in up to its meso- 
thoracic legs, these being used to maintain a grip on the rim of the hole, 
while the hind legs were often waving in the air. The body was occa- 
sionally rotated in a complete circle, the head not being withdrawn 
from the hole.® Evacuation of feces took place during the observa- 
tion, and as there was only a small quantity of whitish sawdust out- 
side the entrance, the indications were that the borer ate most of the 
material taken from the burrow. In about 24 hours this borer was 
completely within the gallery, having progressed approximately 
3 mm. since the observation of the previous day. In another instance — 
the borer advanced at about the same rate, or approximately 6 mm. 
in two days. . 
The females burrow to a depth of at least 6 mm. before starting 
- oviposition. Oviposition was not observed, but probably proceeds 
as described for other scolytids; the female backs out of the gallery 
and then backs in to deposit her egg in a niche in the wall of the 
gallery which she had previously prepared for its reception (4, p. 34; 
15, p.17). After the egg is laid in its niche, the opening into the egg 
gallery is securely plugged with frass cemented together with a sticky 
material, probably secreted by the female beetle (4, p. 34). These 
egg pockets usually ure 2 to 6 mm. apart, but sometimes are almost 
contiguous. Those in longitudinal mines are in the side toward the 
core of the root; those in a horizontal mine are usually on the upper 
and lower sides alternately. Those in completely inclosed galleries 
are often on alternate sides of the gallery. The egg galleries formed 
in May measure from 20 to 30 mm. in length, have four to six well- 
separated egg pockets, and are usually longer than those found later, 
in June and July. These later galleries, probably the second or later 
effort of the females, measure from 15 to 20 mm. long and usually 
their ege pockets are very close together and more numerous than in 
the May galleries. Sometimes as many as nine eggs are found in one 
short gallery. Rarely two females are found together in one 
egg gallery, which is longer and contains more eggs than in the case 
of a single female; in one such case the gallery contained two females 
and 12 eggs. 
The construction of the egg gallery and oviposition in it are together 
a rather slow process. In the laboratory, under conditions of 
higher temperature than would prevail in the soil in the field, one 
female extended her mine 13 mm. and laid four eggs in 14 days. It 
is therefore probable that the construction of the first egg gallery 
occupies the female for nearly a month. This assumption is corrob- 
orated by field observations, which indicate that the second egg gal- 
pes are started about the end of May and during the first part of 
une. 
*See Blackman (4) for a good description, with figures, of a scolytid starting an egg gallery. 
