480 NEW YORK STATE MUSEUM 



Alder borer 



Sapcrda obliqna Say 

 Irregular, gall-like swellings at the base of alder stems, followed by dying and break- 

 ing of the shoots, are very characteristic of this insect. 



The white-footed, legless grub closely resembles that of the appletree 

 borer and is most easily recognized by the food plant it inhabits. 



The adult is a light reddish brown with darker oblique bands on the 

 wing covers. The thorax has a pair of broad, dark brown bands which 

 extend backward onto the base of the wing covers. The spaces occupied 

 by the darker bands on the elytra are depressed, an instance of where 

 coloration is emjjhasized by sculpture. 



Life history and habits. This species is a common one in the State of 

 New York, if one may judge from the numerous dead shoots in alder 

 swamps killed by this species. The beetle oviposits close to the ground in 

 black alder and the larvae frequently girdle the stems, there sometimes 

 b(;ing two or three borers near together, one of which is very apt to work 

 downward three or four inches and often below the surface of the ground ; 

 the others usually tunnel in an opposite direction. The general method of 

 work is very similar to that of the common round-headed appletree borer, 

 and the beetle emerges from a circidar hole very closely resembling that 

 made by the above mentioned species. The adult may be found near 

 the top of alder shoots, and according to Mr Fred. Knab of Chicopee 

 Mass., easily escapes notice on account of its close resem])lance to a with- 

 ered leaflet, and its remaining perfectly motionless, clinging tightly to a 

 branch, with the antennae extended forward. This species has also been 

 taken on birch. 



Distribution. This species has been recorded from Canada south to 

 Mississippi and westward to Wisconsin. It is probably generally distributed 

 in the northeastern United States. 



Natural enemies. Native woodpeckers appear to be very efficient in 

 checking this borer, as we have found a number of infested stems showing 

 the characteristic marks of these beneficial birds. The larvae are also 



