December, '14] 



WEBB: RICE WATER-WEEVIL 



433 



Fig. 23 — Lissorhoptriis simplex 



adult enlarged, h antenna more 

 enlarged (After Tncher) 



guish the weevils, as their general color 

 is much the same as that of the dry grass. 

 Great numbers of weevils pass the winter 

 in this way. Mr. C. E. Hood, one of the 

 writer's predecessors in the study of the 

 biology of this insect, records the finding 

 of large numbers of hibernating weevils 

 in Spanish moss. The writer believes 

 Mr. Hood's observations to be correct, for 

 from his own experience he has come to 

 the conclusion that dead grass is the more 

 favored place of hibernation. 



Emergence from hibernation begins 

 early and ends late in spring. The earliest 

 date knowm to the writer upon which an 

 adult has been observed to be active was 

 March 25. The latest date upon which 

 adults have been found in hibernation was 

 June 26. This gives a period of three 

 months for the emergence of the entire 

 generation of hibernating individuals. 



The adult weevils are usually not noticed in spring until the first 

 flooding of the rice fields. Then almost immediately they are to be 

 found swimming about in the water among the rice plants or resting 

 upon the leaves above water. Sometimes they rest upon the leaves 

 apparently for hours, but when touched promptly "play possum," 

 fall to the water and swim away. They appear to be equally at home 

 either in or out of water. How^ever, it is impossible for them to breed 

 in any but water plants. 



Dissemination from hibernating quarters probably takes place 

 mostly at night. The writer has never observed w^eevils in flight 

 during the day. He has observed them quite frequently flying to 

 lights at night. 



The first injury to the rice plant occurs upon the leaves and is done 

 by the adult weevils, probably both prior to, and succeeding oviposi- 

 tion. This injury takes the form of longitudinal feeding scars, the 

 weevil eating out a longitudinal furrow in the leaf, just as broad as 

 the spread of the mandibles. Only the thin epidermis is left where 

 the feeding is done. Little real damage is done in this way, but the 

 w^ork is very characteristic of this species. 



Copulation and egg laying apparently commence shortly after the 

 adults reach the flooded fields of rice. When ready to deposit an egg 

 the adult female crawls down the rice stem beneath the water and 



