CLOVER STEM-BORER AS AN ALFALFA PEST. 15 
night. They invariably seem to avoid excessive temperature and 
sunlight, and when disturbed immediately drop to the ground and 
feion death. They remain in this motionless position for a long period 
of time and in fact almost seem to know instinctively when a person 
is looking at them. 
OVIPOSITION. 
The adults prefer young succulent alfalfa stems for oviposition. 
The female before ovipositing prepares a rather large nidus in the 
stem. This consists of two parts: The outer larger portion which 
is about one-eighth of an inch square and is only eaten through 
the epidermis and plant tissues immediately adhering thereto, and 
a smaller round opening in the center of this outer square about 
one-sixteenth of an inch in diameter, which extends to the pith of 
the stem. The adult is.thus enabled to introduce her head and 
thorax within the stem and hollow out a cavity in the pith for plac- 
ing the egg. This cavity is usually one-fourth of an inch in length 
and evidently is for the purpose of affording the newly hatched 
larva a place for locomotion and feeding. 
After preparing the egg receptacle, the female deposits the egg, 
usually just below the external orifice and on the opposite wall of 
the stem. After ovipositing, the female teases out the tissues on 
the edge of the inner or round opening so that they practically 
close the hole. A fresh ov?position puncture is almost white or 
colorless in appearance, but after 36 to 48 hours it becomes a dark 
brown spot, and at all times is conspicuous and easily noted, 
especially after the dark color has been assumed. During periods of 
heavy summer rainfall and excessive humidity the alfalfa stem often 
splits open each way from the oviposition puncture, and the stem 
breaks over and is entirely destroyed. In this case, the larva fails 
to develop. | 
During the authors’ observations and those of other members of 
the bureau, more than one egg has never been noted as being placed 
through one oviposition puncture. Two oviposition punctures 
sometimes occur in the same stem, but in each case one larva always 
destroys the other, and thus only one beetle develops in a single 
alfalfa stalk. A. A. Girault (15), who has made an interesting 
observation upon the oviposition habits of this species, has noted 
-at least 15 eggs deposited through a single opening within the stem 
of a species of Leucanthemum. ‘This is described by him as follows: 
After preparing the nidus, the femalc leisurely walks up the stem the length oi 
her body, and after feeling a little, fits the tip of the abdomen into the excavation 
and places an egg. After depositing she wheels in her tracks with almost military 
precision, simply reversing her position and commences to prepare another place for 
an egg in the same excavation. The female works with economy, wheeling about 
