68 



MANUAL OF VEGETABLE-GARDEN INSECTS 



length, oval in outline, strongly convex and pale yellowish to 

 brownish orange in color. The eyes are black and each wing- 

 cover is marked with eight small black spots arranged in three 

 transverse rows. The beetles feed on the foliage, eating out 

 holes in the leaves, and deposit their elongate, yellowish eggs 

 in clusters of forty or more on the underside of the leaves. 

 Each female lays on the average nearly 300 eggs and one beetle 

 was observed to lay over 750. The egg is about -^ inch in 

 length, oval and yellow in color. The eggs hatch in four to 

 nine days and the young larvse begin feeding on the underside 

 of the leaves, skeletonizing them. The 

 larva passes through four stages in the 

 course of its development and becomes 

 full-grown in two or three weeks. It is 

 then about f inch in length, light yellow 

 in color and clothed with stout branched 

 spines. When mature it attaches the tip 

 of its body to the leaf and transforms 

 into a yellow pupa about ^ inch in 

 length. The pupal period occupies from 

 three to five days. The entire life cycle 

 is completed in three to four weeks in New Mexico. In 

 Colorado there is said to be but one generation annually; in 

 New Mexico there are two. 



The seasonal history of the bean ladybird has been studied 

 most carefully in New Mexico. In that region the over- 

 wintered beetles lay eggs from the middle of June to the first 

 of August. The larvae of the first brood are found until the 

 latter part of August, producing a brood of beetles some of 

 which may hibernate. The earliest beetles to mature of the 

 second brood begin laying eggs about the middle of July and 

 continue till the end of the season. The two generations thus 

 overlap during July and August and it is at this time that the 

 larvse and beetles are most abundant and destructive. In 



Fig. 48. — The bean 

 ladybird ( X 3) . 



