26 
Colorado Experiment Station 
If spraying for the twig-borers alone, arsenate of lead (4) used 
just after the buds open, gives good results. Many growers prefer this 
to the lime sulphur treatment. Destroying infested fruit and twigs 
before the larvje leave them aids in keeping this pest in check. 
Plum Goiiger .—This pest feeds upon plums, prunes and nectar¬ 
ines. It is a small gray snout beetle, a quarter of an inch in length, 
with ocher-yellow head and legs, wing covers smooth and without 
humps which are characteristic of many snout beetles. The beetles 
feed upon the fruit, making small punctures in the skin. Eggs are de¬ 
posited in some of the punctures and the grub eats into the pit, de¬ 
stroying the seed. The larva pupates within the seed, the adult com¬ 
ing out about the time the fruit matures. The adults winter over in 
the soil. See Figs. 16 and 17. 
This is probably the worst pest of the native or Americana plums 
in Colorado. 
Remedies .—^Jar the trees early in the morning and catch the 
beetles on sheets held beneath. Do this from the time the blossoms 
are out until no beetles are caught. Spray with arsenate of lead (4) 
soon after the blossoms fall, and again ten days later. 
Plum Curculio .—This beetle is very similar to the preceeding one. 
It is brown to blackish in color, about one-fifth of an inch in length, 
and with two prominent humps and several smaller ones on its back. 
There are two broods. It winters in the beetle stage in the soil, 
and in rubbish. The adult comes out in the spring and feeds upon the 
buds and foliage, and later upon the small fruit. 
The food punctures in fruit are similar to those made by the pre¬ 
ceding species, but the eggs are deposited in skin punctures that are 
distinctly crescent-shaped. The larvae do not enter the pit, but feed 
Fig. 17.—Plum Gouger: a, plum pit showing hole for exit of gouger; b, gouger; c, side 
view of head of gouger showing beak and antenna. (Riley & Howard, Insect Life, Vof. II., 
U. S. Dep. of Agr., Div. of Entomology.) *’ 
