THE CALIFORNIA GRAPE ROOT-WORM. 



(Adoxus obscurus Linn.) 

 BY H. J. QUAYLE. 



The California Grape Root-worm is an insect that attacks both the 

 roots and the growing parts of the vine above ground. It has been 

 known to attack the leaves of the vine in this State for a good many 

 years, but until a year or two ago it was unknown as a root feeder. It is 

 similar in its life history and mode of attack to the well-known grape 

 root-worm of the Eastern States, which is one of the worst pests that the 

 vineyardists there have to wage war against. Our species has been doing 

 considerable damage during the past two or three years, and it promises 

 to be an important enemy of the vine in California. 



Early History in Europe. The first account of this insect, which 

 leaves little doubt as to its identity, was given by Aldrovandi in 1602. x 

 It is one of the important pests of the vine in France, as is shown 

 by the amount of literature on the insect that has appeared in that 

 country. Pluchi 2 in 1732 stated that it passed the winter in the ground, 

 and this is the first suggestion we have of its underground habits, 

 although it was not actually known by this author to feed upon the 

 roots. The first authentic observation on the root-feeding habits appears 

 to have been made in 1849 by Demermety, 3 who found it feeding upon 

 the roots of vines in France. 



It has received rather careful attention from a number of observers 

 in Europe, but probably the most complete account is given in Mayet's 

 "Insectes de la Vigne. " It also occurs, as a grape pest, in Germany, 

 Italy, and Algeria, as well as in France. 



In California. The first account of this insect occurring on vines in 

 California, so far as we have been able to find, is a brief notice in the 

 1 'Pacific Rural Press" for May 29, 1880. It is here stated that " every 

 spring for the last few years there have been received specimens of a 

 dark colored beetle about one fifth of an inch long which eats the leaves 

 of the grapevine until almost skeletonized." It is doubtful from this 

 account just what beetle is referred to, but the description of the beetle 

 and its work on the leaves, and the time of the year of its occurrence, 



1 Des Insectes, p. 472. 



2 Spectacle de la Nature ; Paris. 



3 Jour. d'Agr. de Dijon. 



