10 
noticed simultaneously in that Territoiy and in Colorado in 1S98, when 
it did serious injury to crops. The beetles are gregarious, sometimes 
occurring ' ' in swarms like blister beetles. *' Their brownish gray eggs 
are deposited in irregular masses, usually on the under sides of leayes. 
The}' hatch in about six days, and their lary^e or young commence 
feeding at once, continuing for nine or ten days, when they dig their 
wa^' into the ground, a few days later coming forth as beetles. Al- 
though the beetles do much injury, the principal damage is sometimes 
accomplished by the larva?, hundreds being found on a single small 
plant, which is either consumed or so injured that it shriyels and dies. 
In 1902 this insect did considerable injury to sugar beet in Colorado.^ 
It feeds on seyeral wild plants, blites {Dondla ame^ricana and D, 
Fig. 1. — Monoxia puiicticoIUs: a, female beetle; b, eggs: c, larva, dorsal view; d, larva, lateral view; 
cT, claw of male; $, claw of female — all much enlarged, male and female claAvs more enlarged 
(author's illustration, Division of Entomology). 
depressa), Russian thistle {Sal sol a tragus), and saltbush [Atrijylex 
argentea)^ is double-brooded according to Prof. C. P. Gillette,^ and 
occurs throughout the summer. 
This species is related to the imported elm leaf -beetle, but is larger 
and differenth' marked. The beetle is quite variable . both as regards 
the markings and size, the length being from one-fourth to one-third 
of an inch. It is of oblong form, narrow in front. The color varies 
from pale yellow to entireh' black, while the elytra or wing-coyers are 
more or less distinctly striped. The surface of the thorax is coarsely 
and irregularly punctate. Fiye yarieties or races are recognized. 
The beet-feediup- form is illustrated in figure 1. a. The larva, shown 
in the same illustration, c^ r/, measures when full grown about one-third 
«Bul. 40, Div. Eut., pp. 111-113. 
^Twenty-fourth Rept. Colo. Agric. 
Expt. Stu., 1902, pp. 108-111. 
