THE CLOVER ROOT BORER 19 
leries, but more commonly in superficial burrows in the crowns. It 
seems probable that many die outside the host plants when their 
reproductive life is ended, as the dead parent adults are rarely re- 
covered in cages over growing plants. 
The maximum number of eggs are found toward the end of May 
or the first week of June. Eggs become less common by June 30, 
uncommon in July, rare in August, and very rare in September. 
Davis (9, p. 45) reported that L. Whitney Watkins found an egg in 
a clover root at Manchester, Mich., on September 18, 1893. The 
writer found one egg (which hatched the next day) on September 27, 
1918, at Forest Grove, Oreg. © 
LARVAL AND PUPAL DEVELOPMENT 
The first newly hatched larve are recorded in the field in late May 
or early June. By the first of July many well-grown larve are pres- 
ent but they occur in greatest number after July 15. 
The earliest recorded observations of pupze were made in the field 
at Wooster, Ohio, on July 6, 1896 (46), and at Forest Grove, Oreg., 
on July 10,1918. Pupz do not usually occur in western Oregon 
until after July 15. As observed there they have not been numerous 
until about the middle of August, and never so numerous as other 
stages occurring at the same time, probably because of the brief 
period of this stage and the great diversity in the age and develop- 
ment of the larve. Larve remain in the majority until after August 
15, when new adults rapidly become more numerous than the other 
stages. The first callow adults occur about a week after the first 
pupez are observed. Occasional pup and newly transformed adults 
are observed as late as October, and more rarely in November. Soil 
temperatures usually are too low for development after November 15, 
and only larve and adults are observed then. A condensed sum- 
mary of the seasonal history of the insect is given in Table 4, in 
which are listed the places and dates of observations of various life 
phenomena. 
TABLE 4.—Tabular summary of seasonal history of the clover root borer 
| 
First flight of beetles 
Forest Grove, Oreg.: 
Maximum flight 
Forest Grove, Oreg.: 
Last beetles in flight 
Yambill, Oreg.: 
First eggs 
Forest Grove, Oreg.: 
Apr. 16, 1915. May 2, 1916. July 14, 1915. Apr. 21, 1915. 
Apr. 7, 1916. May 28, 1917. Forest Grove, Oreg.: Apr. 22, 1916. 
May 8, 1917. Wapato, Wash:: July 11, 1916. Apr. 29, 1918. 
Apr. 19, 1918. May 10, 1917. | Silverton, Oreg.: Apr. 27, 1921. 
Apr, 22, 1919. July 13, 1917. Hagerstown, Md.: 
Apr. 26, 1920. Wapato, Wash.: May 18, 1916. 
Apr. 8, 1921. June 18, 1917. Wooster, Ohio: 
Wapato, Wash.: May 17, 1898. 
May 5, 1917. May 17, 1899. 
Hagerstown, Md.: | Michigan: 
ADr. 27, 1915 (?) June 4, 1893. 
Apr. 19, 1916 (?) 
Wooster, Ohio: 
Apr. 26, 1899. 
Lansing, Mich.: 
May 3, 1893. 
Murray. Utah: 
May 18, 1912. 
May 20, 1894. 
