THE BEAN" LADYBIRD. 21 



(20) EssiG, E. O. 



1915. Injurious and beneficial insects of California. 



(21) Merrill, D. E. 



1917. The bean beetle. N. Mex. Agr. Exp. Sta. Bui. 106. 



(22) Orton, W. A., and Chittenden, F. H. 



1917. Control of diseases and insect enemies of the home vegetable 

 garden. U. S. Dept. Agr. Farmers' Bui. 856. 



(23) Chittenden, F. H. 



1919. The bean ladybird and its control. U. S. Dept. Agr. Farmers' Bui. 

 1074. 7 p., 3 fig. 



THE BEAN LADYBIRD IN COLORADO IN 1919. 



By A. E. Mallory, Scientific Assistant. 

 LIFE-HISTORY RECORDS. 



Hibernating adults of the bean ladybird which bad passed the 

 winter successfully began to appear in Colorado in 1919 about the 

 middle of June, the first individuals having been found June 16 

 feeding on beans. A week to 10 days later they began to deposit 

 eggs on the underside of the leaves in clusters of about 40 or more. 

 About 2 weeks later, July 9 and 10. the eggs hatched, and the tiny 

 yellow larvae commenced to feed in a colony near the egg cluster. As 

 they grew older they became separated and did not necessarily con- 

 fine their feeding to the underside of the leaf. As the season ad- 

 vanced, they fed on every part of the plant, blossoms and pods in- 

 cluded. The larvae were present in all stages from the first ap- 

 pearance until at least September 10. On July 22, which was 10 

 or 12 days, after the eggs had hatched, pupae were found. During 

 the early part of the season, when foliage is plentiful, pupation takes 

 place on the underside of the leaf. In case the foliage has been 

 extensively destroyed pupation may take place on either side of the 

 leaf or on both sides, 25 to 30 pupa? on a single leaf being not un- 

 common. As many as 100 on a single leaf were reported in a case 

 where infestation was heavy. This congregating at the time of pupa- 

 tion seems to be characteristic of the species. Pupse were observed on 

 other plants near beans when the foliage of the beans was almost 

 destroyed. 



On July 28 adults of the first brood were observed, and by July 30 

 the}^ were numerous, gradually increasing in number until about 

 September 1 when they seemed to reach their maximum numbers. 

 The first-brood adults are much lighter in color than the hibernating 

 individuals, being a bright yellow at the time of emergence. They 

 gradually become darker, and at hibernating time some are dark red- 

 dish brown, almost if not entirely as dark as the hibernating indi- 

 viduals. Eggs deposited by this new brood were observed August 

 28 and September 2. It is possible that eggs were deposited by this 

 brood earlier than these dates. 



