August, '22 



HOWARD: MEXICAN BEAN BEETLE 



267 



Eastern United States, when it reaches these sections, as it undoubtedly 

 will in course of time. 



Life History Notes 

 t 



Emergence from hibernation was first observed March 22, 1921, when 

 adults and eggs were taken in the field. A series of frosts a week later 

 destroyed all bean plants and eggs but did not affect the adults. Table I, 

 the data of which were taken from 209 experiments, gives an idea of the 

 life history as investigated the past season 610 feet above sea level. 



Table I.- 



-LiFE-HisTORY Data on The Mexican Bean Beetle in the South- 

 eastern United States 



Experi- 

 ment 

 No. 



Mean 

 temp. 



LH 1 



LH4 3G.. 

 LHl 1G2.. 

 LH5 20G2 

 LH6 3G3 



op 



64.9 

 82.7 

 84.6 

 81.1 

 68.6 



Four generations from first egg to first adult were completed in the 

 insectary near Birmingham, Ala., and the temperature would have 

 permitted another generation to develop, at least partially, but this 

 did not occur. A period of from 6 to 10 days, averaging 7 days, elapsed 

 during July and August between the emergence of the female from the 

 pupa and egg deposition. 



BEETLES m HIBERKATION 



ACTIVE PERIOD 



Fig. 9. — Seasonal history of Mexican Bean Beetle, Birmingham, Ala., 1921 



