20 BULLETIN 1426, U. S. DEPARTMENT OF AGRICULTURE 
TaBLe 4.—Tabular summary of seasonal history of the clover root borer—Contd. 
Last eggs First larve Maximum larvee yy ee aaa 
Albany, Oreg.: Forest Grove, Oreg.: Forest Grove, Oreg.: | Forest Grove, Oreg.: 
Aug. 9, 1915. May 15, 1915. July 19, 1915. Aug. 26, 1915. 
Forest Grove, Oreg.: May 17, 1916 (cage). July 18, 1916. Aug. 28, 1916. 
July 22, 1916. June 8, 1917 (cage). July 25, 1917. Aug. 22, 1917. 
Sept. 12, 1917. June 3, 1919. Hagerstown, Md. Aug. 24, 1918. 
Sept. 27, 1918. Hagerstown, Md.: July 22, 1915 (?) | Hagerstown, Md.:: 
Hagerstown, Md.: May 24, 1916 (cage). July 27, 1916 (?) Aug. 25, 1916. 
Aug. 23, 1916. | June 8, 1916. Murray, Utah: | 
Manchester, Mich.: Murray, Utah: Aug. 12, 1911 (?) 
Sept. 18, 1893. June 20, 1912, Wooster, Ohio: 
Wooster, Ohio: July 12, 1898 (?) 
June 8, 1898. July 17, 1899 (?) 
First pup Maximum pupz First adults 
Forest Grove, Oreg.: Forest Grove, Oreg.: Forest Grove, Oreg.: 
July 19, 1915. Aug. 27, 1915. July 27, 1915. 
July 29, 1916. Aug. 23, 1916. Aug. 15, 1917. 
July 25, 1917. Aug. 22, 1917. Aug. 2, 1918. 
July 10, 1918. Wapato, Wash.: Yamhill, Oreg.: 
Hagerstown, Md. Aug. 12, 1915. July 24, 1916. 
July 22, 1915. Hagerstown, Md.: Hagerstown, Md.: 
July 21, 1916. Aug. 15, 1916. July 26, 1915. 
Wooster, Ohio: July 21, 1916. 
July 6, 1896. Wooster, Ohio.: 
July 12, 1898. July 6, 1896. 
July 7, 1899. July 17, 1899. 
FALL ACTIVITY 
In about four days from the time of emergence from the pupal 
stage, the new adults become sufficiently matured to begin feeding, 
and they continue to feed, by enlarging the larval burrows in the 
roots in which they matured, until low soil temperatures limit their 
activity. The adults, with few exceptions, pass the winter in the 
roots in which they have undergone complete development. In 
the event of the death and desiccation of the root in summer or 
early fall, the adults gnaw their way out and seek living roots in 
which to feed and hibernate. Such forced migration may be by 
flight, as two root borers were taken on flight screens at Forest Grove 
between September 18 and October 7,1918. Larve and adults may 
survive until spring on dead roots, provided these do not become too 
dry. In fact, dead, punky clover roots containing many old larval 
galleries are the most successful wintering quarters for the adults. 
Larve probably hibernate most successfully on roots in which there 
is some life. 
LIFE HISTORY 
OVIPOSITION 
After the first mating the fertilized female burrows into a clover 
root of the preceding year’s seeding, or a still older root. These 
burrows usually start on the clover crown but occasionally begin on 
the side of the root an inch or two below the crown. The egg gal- 
leries vary considerably in character of construction and in length. 
Some are simply grooves, some pass from grooves to completely 
inclosed galleries, some are completely inclosed galleries from the 
