432 INJURIOUS AND BENEFICIAL IN/SECTS OF CALIFORNIA. 



THE GRAPE LEAF-FOLDER 



Desmia funeralis Hiilmer (Family Pyralidse) 



(Desmia maculaUs Westwood) 



Description. — The full-grown caterpillars are light green with a 

 dark brown head and a brown spot on each side of the first two seg- 

 ments. The length averages 1 inch. The pupae are inclosed in thin 

 silken cocoons in the leaf rolls, are light brown and ^ inch long. The 

 moths are dark brown or black with a bluish iridescence. The females 

 have two white bands -across the bodies and two white spots and a 

 white border on each of the fore wings. The bodies of the males have 

 but one transverse white band, white wing borders, two white spots 

 on each of the front wings and a single large white spot on each hind 

 wing. The tarsi and apical halves of the antennas of both .sexes are 

 white. The length averages nearly % inch. 



Life History. 3 " — The winter is spent in the pupal stage within the 

 leaf rolls upon the ground. The adults appear in April and May and 

 deposit the eggs singly or in groups upon the leaves. The larva? begin 

 to appear about the first of June and soon fold the edges of the leaves 

 to one third or one half the distance across into a compact roll about 

 the size of a lead pencil. In these retreats the larvae live and feed 

 upon the edges of the leaves. The first brood is comparatively small 

 and little damage is done in the early part of the season. The cater- 

 pillars of this brood are mature by about the first of July, when they 

 pupate and the adults emerge in a week or ten days and lay eggs 

 which hatch into a larger second brood. This second brood usually 

 does the most damage, though it is not at all serious. The pupae of 

 the second brood remain in the rolls after the leaves have dropped 

 and do not transform into adults until the following spring. There 

 are but two broods a year. 



Nature of Work. — The edges of the leaves are tightly rolled by the 

 larvae into a retreat about as large as a lead pencil. The rolls are 

 always on the undersides of the leaves and one or several may be made 

 on a leaf. The caterpillars feed upon the edges of the leaves and occa- 

 sionally upon the young berries and blossoms, but in California have 

 never been present in sufficient numbers to do much damage. 



Distribution. — The grape leaf-folder occurs in the central part of 

 the State, being most abundant in the Sacramento and San Joaquin 

 Valleys. 



Food Plant. — The grape is the only recorded food plant of this 

 insect. 



Control. — The grape leaf-folder has never been a pest in California 

 and control measures have been unnecesary. However, if any serious 

 damage is done, an arsenical spray would be sufficient to protect the 

 crop if applied early. 



' 0<I Quayle, H. J., Bui. No. 192, Cal. Agrol. Exp. Sta., pp. 329-137, 1907. 



