Chapter XIII. 



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. Fatua denudata (Harris.) 

 Order Lepidoptera ; family Sesiid^. 



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

 infested by this borer, giving as an instance 

 C;^^ /'"^^<cP'^ "^® many as four holes in a tree 5 inches in 

 tV^-r^/ /Jo- diameter." He adds: 



I -'^'''' Vi I think the alder must he considered as the favorite 



^-t--„^,«-io;,'U^ \^ host of Mgeria denudatum, as ash trees iu swamps not 



' . j_ V % containing alders are almost exempt from their attacks, 



.Vtv^ v. % while no clump of alders is without evidence of their 



"V'q \\ Si -work. 



'^>»*l ¥•» 2- Saperda obliqua Sav. 



^ ;^rO ' This beetle has been taken from the alder. 



M 



I '■'a \ 3. Hepialue argenteomaculatus Harris. 



yj J 



"^ ij\ {C08SU8 alni Kellicott.) 



\»V^(^y |j Order Lepidoptera ; family Hepialid.e. 



^'^ '°'"^1tSr'"'""' ^r- 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, 1885, p. 173. 



623 



