GRAPE PESTS 
California Grape Root Worm 
*Adoxus obscurus Linn. 
Family Chrysomelidae 
General Appearance 
The adult beetles are about three-six- 
teenths of an inch long, jet black in 
color and partially covered with fine 
whitish hairs giving them a grayish cast. 
The prothorax is noticeably narrower 
than the rest of the body. The antennae 
and legs are usually black, but are some- 
times brown. The eggs are elongated, 
yeliowish-white and one-twenty-fifth of 
an inch long. The full-grown larvae are 
white with brown heads and about one- 
fourth of an inch long. The heads are 
usually curved in towards the ventral 
surface of the body. The pupae are white 
and about the same size as the fully de- 
veloped larvae. 
Life History 
The eggs are laid early in the spring, 
usually in clusters of from one to two 
dozen, in cracks or crevices beneath the 
bark upon the trunk of the vines, any- 
where within six inches above the sur- 
face of the ground. They hatch in from 
eight to ten days and the young larvae 
immediately seek the roots of the vines 
underneath the ground and attack first 
the small rootlets which are often en- 
Fig. 1. Adowus obscurus Linn. 
(Original. ) 
tirely destroyed. The large roots are also 
attacked and large patches of bark re- 
moved. They continue to feed under- 
ground until fall, when they are full 
grown and remain dormant during the 
winter, transforming into delicate pupae 
in the spring and after about two weeks 
emerge as adult insects. The larvae and 
* The light-colored form has the wing covers, 
tibiae and basal half of the antennae brown, 
while the rest of the body is black. This 
species is known as Adowvus vitis Fource., and 
the life history and habits are almost iden- 
tical with those of Adoxvus obscurus Linn. 
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pupae are usually found within a radius 
of fifteen inches from the trunks and at 
a depth from two feet to less. The adults 
appear about May to begin egg-laying and 
disappear in June. 
Food Plants 
The larval forms work upon the roots 
and the adults work upon the foliage and 
fruit of practically all the commercial 
varieties of grapes. 
Control 
Thorough cultivation, close to the bases 
of the vines, will kill many of the larvae 
and pupae. The adults may be kept in 
check by repeated applications of arseni- 
cal sprays. Jarring them into receptacles, 
containing oil, is also recommended. 
E. O. Essie 
Cottony Cushion or Fluted Scale 
Icerya purchasi Mask. 
General Appearance 
The adults are distinguished by large, 
white fluted cottony masses with distinct 
red or yellow bodies, varying from one- 
fourth to one-half inch in length and 
three-fourths as wide. There are two 
varieties, as follows: JIcerya purchasi 
var. crawii Ckll., of which the body 
proper is yellow or light brown, and 
Icerya purchasi var. maskelli Ckll., the 
body of which is very dark brown or 
almost black. The eggs and young are 
bright cardinal red. 
Life History 
The large cottony masses are the egg- 
sacs of the females, and may contain 
from four hundred to a thousand eggs. 
The males soon after hatching secrete 
themselves in a white cocoon for trans- 
formation, which requires nearly one 
month. The females are matured in 
from three to four months. There are 
several broods during the summer, when 
the scale increases enormously and may 
do great damage. 
Food Plants 
All citrus trees, pomegranate, quince, 
apple, peach, apricot, fig, walnut, locust, 
willow, pepper, grape, rose, castor bean, 
spearmint, rose geranium, purslane, am- 
brosia, nettle, sweet-gum, white oak, flow- 
