74 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
As nearly as can be made out without having fresh specimens of 
this species and the eastern form for comparison, there is only slight 
difference in the preparatory stages. 
HABITS AND LIFE HISTORY. 
According to the author quoted, this species is especially injurious 
to the interests of florists, the beetles eating unsightly holes in buds 
and petals of roses, chrysanthemums, and other ornamental flowers, 
feeding also on the leaves, there being an almost unrestricted range of 
food plants. Orchardists often suffer serious losses from the ravages 
of the beetles, which eat into young forming fruit and buds. 
In Doane’s experience, eggs (see fig. 23) were deposited from one- 
fourth to one-half an inch below the surface of the ground, near the 
base of the food plant, sometimes singly, but usually in numbers of 
between from twenty to fifty. Eggs 
in confinement hatched in about eight- 
een days (temperature not stated). 
Larve of various sizes were taken 
about the roots of different plants in 
March, April, and May, these obser- 
vations being presumably made at 
Palo Alto, Cal. It was noticeable 
that the larvee did not bore into the 
roots, as do our eastern species, but 
Fic. 23.—The western twelve-spotted cucum- ate the roots from the outside, some- 
pacar ag epee Snes sii times cutting young rootlets entirely 
greatly enlarged; c, d, highly magnified. in two. ‘They were found in abun- 
ee te ney EEE REE? dance feeding on the roots of sweet 
pea and alfalfa and sparingly on other plants. When the larva 
becomes full grown it approaches the surface of the ground and 
forms an oval or spherical cell, in which it remains ten or twelve days 
before transforming to the pupa. The pupal period lasted under 
observation from ten to fourteen days. Pupz were first noticed 
early in April. The periods will vary with temperature, and there 
are indications of a second generation in southern California. 
OTHER RECORDS OF INJURY. 
In 1880 mention was made of injury by this species to the fruit of 
apricot in California.© Injury to garden plants was also noted. Men- 
tion was made of great destruction to fruits and vegetables in 1890 in 
California.° The following year Mr. Koebele reported injury to 
young corn by the larve at Alameda, Cal., often three to five larve 
being observed cutting off the roots of a single plant.© <A series of 
4 Comstock: Ann. Rep. Comm. Agr. for 1879 (1880), p. 246. 
6 Koebele: Bul. 22, O.S., Div. Ent., U. S. Dept. Agr., p. 87, 1890. 
¢ Insect Life, Vol. III, p. 468, 1891. 
