432 journal of economic entomology [vol. 7 



Parasite Enemies 



No cases of true parasitism have been observed, but a type of para- 

 sitism does occur which may be termed incidental or accidental, as 

 such external parasites as those belonging to the genus Aphelinus, 

 which lie beneath the scale covering and suck out the entire contents 

 of the second or third-stage San Jose scales; pupating between the 

 scale covering and the empty skin of the scale and at the same time 

 destroying the internal parasite as well. 



Geotropism and Phototropism 



The adult parasites show both positive geotropism and phototropism 

 and these two reactions, together with the instinct of the parasite to 

 search for scales, no doubt accounts for the fact that the scales on the 

 smaller and outermost branches and twigs of infested material are well 

 parasitized. This fact was also noted by H. E. Hodgkiss and P. J. 

 Parrott (Jour. Econ. Ent., vol. VII, 227, April, 1914). 



NOTES ON THE RICE WATER-WEEVIL (LISSORHOPTRUS 



SIMPLEX SAY) 



By J. L. Webb, Bureau of Entomology 



The amount of damage done yearly to the rice crop by the rice water- 

 weevil is extremely hard to estimate. In most cases no rice is killed 

 outright. On the other hand practically every rice field is infested 

 to a greater or less degree. The effect of an attack is the pruning off 

 of the roots near the base of the stalk. In severe attacks all the roots 

 may be cut off, in others only a few. Where the pruning is not too 

 severe, the rice plant promptly throws out new roots, continues to 

 live, and will mature. Yet we do not know just how much has been 

 lost in weight or quality of yield. The difficulty is in finding a field 

 of rice entirely free from attack with which to compare infested fields. 

 In extreme cases the rice plants are killed and the loss is then more 

 easily estimated. In general, however, the loss from this source is 

 considerable, and well worth active efforts in the way of prevention 

 or elimination. 



Seasonal History and Habits 



According to the writer's observations the adult passes the winter 

 in dead grass, especially grass that is matted down upon the ground. 

 In order to find the weevils in hibernation the grass must be lifted 

 up and thoroughly shaken out, allowing them to fall to the ground. 

 Close examination of the debris is then necessary in order to distin- 



