THE CLOVER ROOT BORER mI 
adult borers, which attempt migration in response to the stimulus of 
the first warm days of late March. In 1919, root borers were swept 
as early as March 29 from winter wheat which had been seeded on 
clover sod the previous fall. This was three weeks earlier than the 
emergence of beetles from undisturbed clover. On February 25, 
1921, six weeks earlier than the first fight from undisturbed clover, 
Max M. Reeher noted a root borer crawling on the ground in a 
wheat field seeded on clover sod. That this unseasonable activity 
is detrimental to survival is indicated by the writer’s unsuccessful 
attempts to start outdoor colonies in cages much earlier than the 
normal period of flight. 
MATING 
The first mating is believed to take place in the spring during the 
time just previous to flight. Copulation at this time probably occurs 
in the hibernation chambers in the roots of the host plants, on the 
clover crowns, and on the surface of the ground. Whenever in 
the writer’s experiments males and females were brought together 
at room temperatures during this season, or even in the fall, mating 
or attempted mating was observed. Mating in the field has been 
observed very rarely, although Schmitt (39, p. 394) stated that near 
Mainz the beetles are often found in copula and resting on clover 
plants at the end of April and beginning of May. The writer observed 
one case of mating in an enlarged larval burrow of the previous year 
in an old clover root dug up in the field on May 13, 1915. An 
attempted mating (unsuccessful) was observed on the surface of the 
sround on April 24, 1918, when the temperature at the surface was 
62°F. A case of mating in a cage in the laboratory was more closely 
observed. In this instance the male appeared to choose a female 
whose head and part of the prothorax were concealed in a superficial 
burrow. The male established connection after about 10 minutes’ 
endeavor. Copulation lasted 25 minutes, with very slight movement 
on the part of either, the female discontinuing feeding during the pro- 
cess. All other cases of mating observed in cages occurred either 
remote from the roots or on the exterior of the roots. The observed 
facts that females predominated in the first flights, and that all but a 
very small percentage of them had been fertilized before capture in 
flight, are also indicative of a general mating previous to the first 
spring flight. 
MATURITY OF OVERWINTERED LARVZ 
The overwintered larve resume feeding in their burrows as the 
temperature permits and, according to records of observations made 
in various parts of the country, usually reach maturity, pupate, and 
become adults in May, sometimes as early as April or as late as June. 
Webster (46, p. 144) reported overwintered larve in Ohio as late as 
May 27, and a pupa of an overwintered larva on May 31,1898. E. J. 
Vosler noted, at Murray, Utah, a large percentage of overwintered 
larve in April, and pup, apparently from overwintered larve, on 
June 6 and June 20, 1912. be anid larve have been found as 
late as May 17, 1915, at Forest Grove, Oreg. 
