THE DESERT CORN" FLEA-BEETLE. 
-The desert corn flea-beetle: 
Prepupa. Greatly enlarged. 
(Original.) 
partially covered with short stiff hairs. In color and texture they 
are so much like the corn roots in which they are found feeding that 
one will often overlook a larva, even with the aid of a microscope. 
However, when quite numerous, the full- 
grown larvae are easily found on the roots 
of a corn plant or in the surrounding soil. 
The full-grown larvae just previous to 
changing to prepupae are often as much as 
5 mm. (three-sixteenths of an inch) long, 
varying from 3.5 to 5 mm. in length; the 
average length being about 4 mm. They are opaquely white in color, 
well segmented, and cylindrical in form as compared with the younger 
larvse. 
THE PREPUPA. 
The prepupa (fig. 4) is the full-grown larva which has shrunken 
preparatory to pupation, and is thus reduced to about one-half its 
former length, though it is considerably greater hi 
diameter. It usually lies quietly, in a curved position 
resembling in shape a question mark. It is segmented 
and of the same texture as the full-grown larva. 
THE PUPA. 
The pupa (fig. 5) very closely resembles the adult in 
size and appearance. It varies from 1.5 to 2 mm. in 
length and from 1 to 1.3 mm. in width. It is white 
when first formed, and has all appendages firmly com- 
pressed against the body. It is quite delicate, soft 
bodied, and sparsely covered with fine hairs. 
Fig. 5.— The desert 
corn flea-beetle: 
Pupa. G r e a t ly 
enlarged. (Origi- 
nal.) 
LIFE HISTORY AND HABITS. 
THE LIFE CYCLE. 
The total length of the life cycle of this beetle in the Southwest 
averaged 46.3 days, with a minimum of 31 days in July and a maxi- 
mum of 79 days in March, April, and May. This, of course, is subject 
to variation as hi the case of most insects, and depends upon prevail- 
ing meteorological conditions. 
The average length of the combined egg, larval, and pupal stages 
(Table I) of 82 specimens averaged 37.5 days for all temperatures, 
varying from a minimum of 24 days in June to a maximum of 65 days 
in March. Adding to this the average time required for the female 
to complete her development after issuing, before she deposits eggs, 
namely 9.8 days, gives the above-mentioned length of 46.3 days for 
the complete life cycle. 
