Chapter VI. 
INSECTS INJURIOUS TO THE COTTONWOOD. 
Populus monilifera, 
AFFECTING THE ROOTS. 
1. THE COTTONWOOD ROOT borer. 
Plectrodera seal a tor Fabr. 
The following correspondence regarding this borer appeared in a 
newspaper : 
Herewith is an entomological specimen found at the foot of the cottonwoods about 
my house, and the larva? are boring the trees. What can I do to prevent their kill- 
ing my trees?— J. R., Manhattan, Kans. 
The large and beautiful black and white long-horned beetle which you send is the 
Pleclrodera scalator Fabr. Its larva has long been kuown to bore in the roots of 
willows, and as most insects that attack the willow also attack the cottonwood, it is 
natural that this species should form no exception. I can give no remedy from 
experience, and can only recommend the same preventive and remedial measures 
that are used against the round-headed grub. (C. V. Riley.) 
AFFECTING THE TRUNK AND BRANCHES. 
2. The poplar borer. 
Saperda calcarata Say. 
Order Coleoptera ; family Cerambycid^:. 
In the Western States, including Colorado, it causes wide-spread 
injury and destruction to the cottonwood trees. (Riley. See the pop- 
lar borer, p. 435.) 
3. HyperpJatys aspersus Say. 
Boring in the dry twigs at Columbus, Tex.; the perfect insect is to 
be found throughout spring and summer, according to Schwarz. 
(Riley.) 
4. Oberea schaumii Leconte. 
The larva burrowing in the twigs makes a very smooth cylindrical 
burrow, the perfect insect appearing in the middle of June at St. Louis, 
Mo. (Riley.) 
5. Oberea mandarina Fabr. 
The larva bores in the thin twigs at St. Louis, Mo., the imago issuing 
in the middle of April. (Riley.) 
