MEXICAN BEAN BEETLE IN THE SOUTHEAST. 13 
In the Southeast the beetles begin to leave their winter quarters In 
the spring as early as late March and early April, or at about the time 
when early garden beans are coming up. At Birmingham, Ala., this 
date was March 22 in 1921, and April 6 in 1922. At Chattanooga, 
Tenn., it was early in May i in 1922. At Thomasville, Ga., the first 
beetles emerged in the field March 27, 1922. One individual of a 
colony of beetles, marked black, November 18, 1921 (Group 2, Table 
6), was collected in a bean field April D292 2: three-fourths of a mile 
from the place where it had spent the winter. The beetle is thus able 
SS N 
QLERWINTERED 
Pee ee a 
FIRST GENERATION aaa ~ 
FIRST. GENERATION 
BEETLES 
SECOND GENERATION 
LARVAE | 
SECOND GENERATION 
LESLIE: Ss 
THIF-O GENEFAT/ON 
LARLE 
ae Ses = 
TH/PD GENERAT/ON rad 
BEETLES ee 
we ja res 
LARLCE = 
FOURTH GENERATION ee 
VEGI MAS 
BEETLES /N HIBERNAT/ON BB | ACTIVE FEAIOD—-LARVE SS 
ACTIVE PERIOD— BEETLES “@®\ LARLY RECORDS OF /921— ~----— 
Fie. 8.—Seasonal life history of the Mexican bean beetle: Composite chart prepared from insectary records 
and field observations during 1921 and 1922 near Birmingham, Ala. (eggs and pup not shown). Width 
of bands shows relative abundance of beetles and larve in the field. The insect is most abundant in 
July. 
to make extensive flights at this time of the year. In New Mexico, 
J. EK. Graf found beetles hibernating 74 miles from the nearest- bean 
field, and still farther from the most likely source. 
The spring migration lasts until early June, covering a period of 
about two months. The beetle flies consider ably all during the 
summer from field to field and travels great distances. 
During August, 1921, and late July, 1922, the beetles became 
restless and were often on the wing. ‘During this period beetles a 
week or more old fed less than earlier in the season. It is believed 
that the greatest distribution occurs during the late summer and early 
fall, but the spring migration is also undoubtedly of great importance. 
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