Chapter XIIL 



INSECTS PREYING UPON THE ALDER. 



Alnus serrulata and A. incana. 



Although the alder is a useless shrub, it harbors a number of borers 

 and other insects which prey on other forest and fruit trees. The fol- 

 lowing list is by no means a perfect one, and will doubtless be greatly 

 extended by future observations. Alder insects are numerous in Eu- 

 rope: Kaltenbach enumerating 120 species, comprising 33 species of 

 Coleoptera; 63 Lepidoptera ; 11 Hymenoptera (Tenthredinidse), and 

 13 Hemiptera. 



BORING IN THE TRUNK. 

 1. Falua denudata (Harris.) 

 Order Lepidoptera ; family Sesiid.e. 



Mr. Devereaux writes me that in New York the alder is very badly 

 infested by this borer, giving as an instance 

 "as many as four holes in a tree 5 inches in 

 diameter." He adds: 



I think the alder must be considered as the favorite 

 host of jSlgeria denudatum, as ash trees iu swamps not 

 containing alders are almost exempt from their attacks, 

 while no clump of alders is without evidence of their 

 work. 



2. Saperda obliqua Say. 



This beetle has been taken from the alder. 



3. Hepialus argenteomaculalua Harris. 



{C088U8 alni Kellicott.) 



Order Lepidoptera ; family Hepialid^. 



Fig. 'iOi.— Saperda obliqua. 

 Smith del. 



Dr. Kellicott* has described the prepara- 

 tory stages of this borer, which he at first sup- 

 posed to be an undetermined Cossus. See Ent. Amer., iv, p. 153, 1888; 

 also p. 346. 



* On the preparatory stages of an undetermined Cossus, Entomologica Americana, 

 i, 18S5, p. 173. 



623 



