BEETLES RELATED TO GRAPE ROOT-WORM BEETLES. 
15 
(PL TV, fig. 2, in comparison with fig. 1) extending from the main 
root a distance of several feet. The extremities of such roots are 
frequently dead and in a decaying condition, and the portion near 
the stem is much channeled and pitted by the feeding of the larger 
larvae (PL III). The life of such vines during this infestation has 
been sustained by the throwing out of new fibrous roots either at 
the crown or from the large lateral roots at a short distance from the 
base of the vine. If the number of larvae increases sufficiently to 
eat off these new fibers, the whole vine declines quite rapidly, and the 
effect of the attack is readily recognized by a sickly stunted growth 
of vine and undersized clusters of fruit, and in extreme cases by the 
early shedding of foliage and actual shriveling of fruit before the 
ripening period. 
BEETLES RELATED TO THE GRAPE ROOT-WORM BEETLE. 
The grape root-worm is a member of the large group of leaf-eating 
beetles known as the Chrysomelidae. To this family belong the 
common Colorado potato beetle 
(Leptinotarsa decemlineata Say), 
the elm leaf-beetle (Galerucella lu- 
teola Mull.), the asparagus beetle 
(Crioceris as para gi L.), several 
important pests of the genus 
Diabrotica, the grapevine flea- 
beetle (Haltica chalybea 111.), and 
many other injurious beetles. 
Closely related to Fidia viti- 
cida Walsh (fig. 10) is the Cali- 
fornia grape root-worm (Adoxus 
obscurus L.) (fig. 2), of which 
there are two varieties, namely, 
a black form, known as A. obscu- 
rus, and a bicolored form, known 
as A. obscurus vitis. Both vari- 
eties occur in this country and 
have been reported from sev- 
eral widely separated States and 
from Canada. It is found generally in Europe and throughout 
Siberia. At present it is becoming injurious to vineyards in Cali- 
fornia, infesting the European varieties of the cultivated grape. A 
valuable contribution to the knowledge of this insect was published 
by Mr. H. J. Quayle a in 1908. In habits this beetle is in most 
respects similar to the eastern grape root-worm, Fidia viticida, and 
the two pests can thus be combated with similar methods. It will, 
however, be necessary to take into consideration the local conditions 
FIO. 2. — The California crape root-worm [Adoxtu 
dbseurut)'. Adult or beetle. Much enlarged. 
(Original.) 
o Bul. 195, Gal. Agr. Exp. Sta., 1908. 
