FAMILY ELATERIDjE. 87 



' ■ ' ' en said in the agrcultural journals about the use of substances supposed to 



be noxious to this insect, still there is no proof that any such remedy has been effectual. 

 .Salt is usually relied on, but experience does not sustain its use. So far as salt contributes 

 to the amount of fertilizing matter, it will prove useful : beyond that, it is useless. 



In gardens where these larva 1 are common, Mr. Harris recommends the English mode 

 of extirpating them : this mode consists in baiting them with slices of potatoes or turnips, 

 which are scattered over the ground at night. Early in the morning the larvae are found 

 above ground feeding upon the bait, when they are collected and destroyed. 



Genus ELATER. 



This genus is characterized by the shortness of the. antenna?, which have a short robust 

 basal joint, the second and third joints small and subglobose, and with their margins 

 serrate upon their outer sides. Head small and retracted ; eyes small : thorax gene- 

 rally elongate, with the posterior angles produced : body only slightly convex, linear 

 elongate, sometimes subovate : legs short ; tarsi simple. 



Elater (Alaus) oculatus (Fab.). ( Plate v, fig. 6.) 



Form elongate, depressed. Color black, sprinkled with gray. Head small : thorax large, 

 quadrangular, and marked by two ovate black velvety spots situated rather in ad- 

 vance of the middle. Elytra are marked with slender lines ; posterior angles rounded. 

 The underside of the body, and of the legs, is covered with a gray mealy substance. 

 This singular beetle is found in midsummer upon walls and fences. It is one of our 

 largest beetles ; varying, however, from 1 \ to 1 1 inches in length : the largest specimens 

 are nearly half an inch wide. It is glossy black, powdered with white specks. The head 

 has a deep wide impression ; the prothorax is an oblong parallelogram, and the eyelike 

 spots are surrounded by a white ring. It is widely distributed, as I have found it south and 

 north. It appears, therefore, at different times in dirferent latitudes : in North-Carolina, 

 the last of May ; in Pennsylvania, in June ; and in New-York and New-England, in July 

 and August. 



Mr. Haldeman has found the larva of this beetle in ash trees in an incipient decay : it 

 is of various sizes. Mr. Harris has found the larva in old apple trees : it is not, therefore, 

 confined to a single species of trees. In old trees infested with them, it is recommended 

 to remove and burn them. 



The larvae are of a yellowish white color, or reddish ; and, when fully grown, the largest 

 individuals measure two and a half inches in length. The head is rough, brown and broad; 

 the mandibles are strong and curved : they have six legs, and the last segment of the body 

 is furnished with a prop foot ; and the sides are armed with hooks and short spines. 



