10 



CEREAL AND FORAGE INSECTS. 



that there seemed no other alternative than to concede this to be the 

 normal mode of oviposition. Eggs removed from the basal leaf 

 sheaths are illustrated, greatly enlarged, in figure 8. While they are 

 somewhat obscure when freshly deposited, they change to a dark color 

 in a few days, and, though minute, are then easily distinguishable. 



SEASONAJL HISTORY. 



In the vicinity of Washington, D. C, the adults come forth from their 

 hibernation in the fields as soon as the warm weather starts the young 

 growth of the clover, probably during the last of March in ordinary 

 seasons. The sexes pair, and egg deposition soon commences. Fe- 

 males brought from the fields near Washington, on April 1, during the 

 somewhat cold and backward spring of 1909, deposited eggs indoors 

 on April 6. In the fields the first eggs were probably overlooked 



because it was not known on just what part 

 of the plant it was necessary to search for 

 them. As observed by Mr. Wildermuth, 

 the egg period varied from seven days 

 twenty hours to eight days twelve hours. 



The larval period varies from seventeen 

 to twenty days, the former being probably 

 near the normal. The larva molts twice, 

 the first instar occupying from three to 

 seven days, the second from six to 

 seven days, and the third about seven days. 

 The pupal stage occupies, normally, 

 about six days, and the entire period from 

 egg to adult about thirty- two days. Of 

 course temperature will always affect the length of the different 

 periods to some extent. 



While there is clearly but a single annual generation, the breeding 

 season is greatly prolonged, egg deposition probably covering upward 

 of six weeks, and late in this season all stages may be observed 

 at the same time. 



While the larvae can feed on all parts of the clover plant above 

 ground, they prefer the tenderest unfolding leaves, and in the fields 

 they select these parts and feed among the folds; later, they attack 

 the heads, both young and in full bloom (fig. 3, b). While the 

 larvae of both PJiytonomus pimctatus and of the species under consid- 

 eration frequently occur on the same plant, the work of the two 

 is quite different and easily separated. This difference is shown in 

 figures 3 and 7, the latter figure illustrating the work of both species 

 in the same leaf. 



After emerging, the adults probably scatter abroad over the fields 

 and hibernate among leaves, matted grass, and other rubbish, 



Fig. 8.— The lesser clover-leaf weevil: 

 Eggs. Greatly enlarged. (Original.) 



