208 



THE AMERICAN 



INSECTS INJURIOUS TO THE GRAPE-VINE— No. 8. 

 Tlie Grape Leaf-folder. 



{ Desmia maciilalis, H'"est.) 



[Fig- li7.1 



Colors— (1 and 2) grass-gi-eeu; (3) browu; (4 and .1) black 



The subject of this sketch has long been kuowii 

 to depredate on the leaves of the Grape-vine in 

 many widely separated parts of North America. 

 It is not uncommon in Canada West, and is 

 found in the extreme southern parts of Georgia. 

 It appears to be far more injurious, however, in 

 the intermediate country, or between latitude 

 35° and 40°, than in any other sections, and in 

 Southern Illinois and Central Missouri proves 

 more or less injurious every year. It belongs to 

 the same family (Asopid^e) as our notorious 

 Clover-worm, which attacks our clover stacks 

 and mows. It was first described and named 

 by "Westwood*, who erected, for it, the genus 

 Desmia. 



This genus is characterized by the elbowed or 

 knotted appearance of the S antennie, in con- 

 trast -with the smooth, thread-like ? antennas ; 

 the maxillary palpi are not visible, while the 

 compressed and feathery labial palpi are recurved 

 against the eyes, aud reach almost to their sum- 

 mit; the body extends beyond the hind wings. 



Tlie moth of the Grape Leaf-folder is a very 

 pretty little tiling, expanding on an average 

 abuost an inch, with a length of body of about 

 one-third of an inch. It is conspicuously marked, 

 and the sexes differ sufficiently to have given 

 rise to two names, the female having been named 

 Botys hicolor. The color is black, with an 

 opalescent reflection, and the under surface differs 

 only from the upper in being less bright ; all the 

 wings are bordered with wliite. The front wings 

 of both sexes are each furnished with two white 

 spots ;t but wMle in the male (Fig. 127, 4) there 

 is but one large spot on the hind wings, in the 

 female (Fig. 127, 5) tliis spot is invariably more 



*Mag. Zool., pavM. Guerin, 1831; pi. '2. 



■fMr Glover, in the Agricultural Report for ]8.i4, p. 79, 

 says that the male has a semi-lunar mark of white ou the 

 outside of each spot, which in his figure, pi 6, ibid., is very 

 distinct. In dozens of specimens bred in Illinois and Missouri 

 no such mark appears, thougli there is an apparent coinci- 

 dent shade, barely distinguished from the black ground- 

 Color, on the outside of each spot in both male and female. 



or less constricted in the middle, especially above, 

 and is often entirely divided into two distinct 

 spots. Tliebodyof the male has but one distinct 

 transverse band, and a longitudinal white dash 

 at its extremity superiorly, while that of the 

 female has two white bands. The 

 antennae, as already stated, are .still 

 more characteristic, those of the male 

 being elbowed and thickened near 

 W the middle, while those of the female 

 are simple and thread-like. 



There are two broods in this lati- 

 tude — and probably three farther 

 south — during the year; the first moths 

 and white. appearing in June, the second in 

 August, and the worms produced ft-om tliese last 

 hibernating in the chrysalis state. The eggs are 

 scattered in small patches over the vines, and 

 the worms are found of all sizes at the same time. 

 These last change to chrysalids in 24 to 30 days 

 from hatching, and give forth tlie moths in about 

 a week afterwards. 



The worm (Fig. 127, 1) folds rather than rolls 

 the leaf, by fastening two portions together 

 by its silken threads ; and for this reason, in con- 

 tradistinction to the many leat-roUers, may be 

 popularly known as the '• Grape Leaf-folder." 

 It is of a glass-green color,* and very active, 

 wriggling, jumping and jerking either way at 

 every touch. The head and thoracic segments 

 are marked as at Figure 127, 2. If let alone 

 these worms will soon defoliate a vine, and the 

 best method of destroying them is by crushing 

 suddenly within the leaf, with both hands. To 

 prevent their appearance, however, requires far 

 less trouble. The chrysalis is formed within the 

 fold of the leaf, and by going over the vineyard 

 in October, or any time before the leaves fall, 

 and carefully plucking and destroying all those ' 

 that are folded aud crumpled, the supply for the 

 following year will be cut off. TJiis should be 

 done collectively to be positively effectual, for 

 the utmost vigilance will avail but little if one is 

 surrounded with slovenly neighbors. 



"We believe this insect shows no preference for 

 any particular kind of grape-vine, having found 

 it on well nigh all the cultivated, as well as the 



* We subjoin a description of tliis worm, as first given by 

 us in the Prairie Farmer Annual for IStiS. Avex'a^e length, 

 80. Largest on abdominal joints, and tapermg thence 

 slightly each way. Color glass-green, always darker above 

 than below. A narrow darker dorsal line, with each joint 

 swollen into two transverse wrinkles. Laterally paler or 

 yellowish, and a large and distinct piliferous spot on eacli 

 joint, with others scarcely visible with a lens. Head 

 fidvous, polished, horizontal, with two small eye-spots aud 

 two larger dark patches. Joint 1 of the same color, and 

 marked as in Figure 127, 2. Joint 2 has two small spots, 

 with an intermediate larger one, on each side Legs yel- 

 lowish. Acquires a carneous or pink tint before changing 

 to chrj^salis, which latter is of tlie normal color, size and 

 formofFigiU'e 127, 3, and has at the tail several very minute 

 curved hooks, joining and forming into a point 



