INSECTS AND INSECTICIDES 
!7 
INSECTS INJURIOUS TO THE PLUM. 
ATTACKING THE FRUIT. 
PLUM GOUGER. (Coccotorus prunicida.) 
A small but rather robust snout-beetle about a quarter of an 
inch in length; color a leaden gray with head and thorax oeherous 
yellow; wing covers smooth without prominent humps on them. 
The beetle eats pin-holes in the growing plums in which it lays its 
eggs. The larva or grub eats into the pit and feeds upon the kernel, 
and later eats a hole out through both pit and flesh of the plum 
just before the plum matures (Fig. io). The only insect in Colo¬ 
rado injuring the fruit of the plum to any extent. 
Remedies. Jar the trees early every morning, or in the evening, from 
the time the blossoms are out till very few beetles can be obtained, catch¬ 
ing them on a sheet spread beneath. It only takes a very few beetles 
to do a great amount of harm, as I have found by actual count that a 
single female may lay as many as 450 eggs.* Gathering and destroying 
fu- s . n » plums during the early part of July would nearly exterminate 
this insect. Spraying with an arsenical poison (3,4, 5, 6,7, 8) once, a few 
days before the trees blossom, and once or twice after, will give con¬ 
siderable protection. Use the poisons in two-thirds ordinary, or standard 
strengths. Arsenate of lead (5) is probably the safest to use on the 
foliage of the plum. 
PLUM CURCULIO. (Conotrachelus nenuphar.) 
This beetle is often confused with the preceding. As yet it has 
not been reported in Colorado. It is liable any year to appear in 
our orchards and all should be on the look out for it so as to do all 
possible to stamp it out or prevent its rapid spread. It is as destruct¬ 
ive to the European varieties of plums as the codling moth is to 
apples. The beetle is brown to blackish in color, is about one- 
fifth of an inch long, and has two prominent humps and numer¬ 
ous smaller ones upon its wing covers. The beetle makes a cres¬ 
cent shaped cut in the flesh of the fruit where an egg is deposited 
and the grub does not enter the pit but feeds on the flesh outside 
ofpt, causing the fruit to fall. 
Remedies.—Jarring and spraying as in case of the preceding species. 
Should anyone find what he thinks to be the work of this in¬ 
sect in an orchard, it is hoped he will notify the Experiment Sta¬ 
tion at once. 
ATTACKING THE FOLIAGE. 
FRUIT-TREE LEAF-ROLLER. (Archips argyrospila) 
See under apple insects. Use the poisons only two-thirds as 
*Insect Life, III., p. 227. 
