INDIRECT INJURIES CAUSED BY INSECTS. 173 



Here I may just mention a few other insects which 

 devour grains that are the food of man, concerning which 

 I have collected no other facts. The rice-weevil (Calan- 

 dra Qrijzce} is very injurious to the useful grain after 

 which it is named, as is likewise another small beetle, 

 Lyctus dentatus, F. (Sylvanus^ Latr.) : and an Indian grain 

 called in the country Joharre, which appears to be a 

 species of Holcus or Milium, is the appropriate food of 

 another species of Calandra a , which I found abundant 

 in it. 



Rye, in this island, is an article of less importance than 

 wheat ; but in some parts of the continent it forms a prin- 

 cipal portion of the bread-corn. Providence has also ap- 

 pointed the insect means of causing a scarcity of this spe- 

 cies of food. The fly before noticed (Oscinis Pumilionis) 

 introduces its eggs into the heart of the shoots of rye, and 

 occasions so many to perish, that from eight to fourteen 

 are lost in a square of two feet. A small moth also (Mar- 

 garitia Secalis) which eats the culm of this plant within 

 the vagina, thus destroys many ears b . In common with 

 wheat and barley it also suffers from Leeuwenhoek's 

 wolf and the weevil. 



Barley likewise, another of our most valuable grains, 

 has several insect foes. The gelatinous larva of a saw- 

 fly (TentkredO) L.) preys upon the upper surface of the 

 leaves, and so occasions them to wither. Musca Hordei 

 of Bierkarider also assails the plant. A tenth part of the 

 produce of this grain, Linne affirms, is annually de- 

 stroyed in Sweden by another fly, not yet discovered in 



a Curculio testaceus, Ent. Brit. 



b Marsham in Linn. Trans, ii. 80. De Geer notices the injury done 

 by this fly to rye, and observes that before it had been attributed to 

 frost, ii. 68. 



