Vine Moths
The larvae of several species of Moths feed on the leaves, twigs, or young fruit of Vines. Some of them are Hawk Moths (see Sphingidae), the Elephant Hawk Moths (Deilephila Elpenor and D. Porcellus) being the commonest. Others belong to the Night Moths (see Noctua). Of the latter may be specially noted the White-line Dart Moth (Agrotis Tritici), the Large Yellow Under-wing Moth (Triphaena pronuba), and the Gothic Moth (Noenia typica). All three feed on many plants, the two first-named being almost omnivorous; and all of them destroy the shoots and leaves of Vines, though the larvae differ a good deal in their habits. Those of Agrotis Tritici and of Triphoena pronuba hide in the soil by day, but at night they gnaw the young shoots near the ground; and it is thus difficult to detect them. The methods recommended against Surface Caterpillars may be employed to lessen their numbers. The larvae of Noenia typica feed, in autumn, on the upper surface of the leaves of most kinds of fruit-trees, including Vines. The young larvae live in companies, packed side by side, almost motionless, but eating away the surface membrane of the leaves steadily forward, and leaving brown, dead patches behind them. When about a fortnight old, they drop to the earth, and thereafter feed on low plants, till the cold weather of winter makes them go under shelter till spring, when they resume their life on the low herbage. They are dull brown, with a darker line down the back and one on each side, and a series of oblique, short, white lines along the lower part of each side. It is easy to remove the companies of larvae by hand-picking, if they are doing injury to the Vines. Certain of the smaller Moths belonging to the Tortricina (which see) are extremely destructive in the vineyards of France and Germany; but they are seldom the causes of much harm in British vineries, though they occur sparingly in England. Oenectra Pilleriana (called also Tortrix Pilleriana) has been the subject of very exhaustive investigation, by Audouin and other French naturalists, under the name "Pyrale de la Vigne." Its larvae live in rolled Vine leaves, and are very hurtful on the Continent; but the insect is too rare in England to call for a longer notice here. An allied insect (Eupaecilia ambiguella) is almost equally hurtful abroad, as the larvae feed on the flower-buds and on the young grapes, and envelop the clusters in webs, which prevent the growth of the fruit, and promote its early decay. This insect, also, is too rare in England to be dangerous. The fore wings reach a little over 1/2in. in span; they are ochreous, with a greyish streak along the basal half of the front margin, and a broad, slanting, dark grey bar about the middle of the wing; the head and thorax are ochreous. Lobesia reliquana (also called Tortrix vitisana and Grapholitha botrana) has very similar habits to the last-named species, devouring the flower-buds, and spinning the clusters of young fruit up in webs. In bad attacks, as much as half the crop has been lost in this way. This insect has been extremely troublesome in Austria. It is not rare in the South of England, though it has done little mischief in this country as yet. It is a little less than 1/2in. in span of fore wings, which are chestnut-red, marbled with pale buff, and with two dark brown, white-edged, triangular spots on the hinder margin of each. The change into pupae occurs in the soil below the Vines. The larvae may be detected by their webs, and should be removed, either by hand-picking the ravaged clusters, or by shaking or jarring them above a sheet, tarred tray, or any other contrivance for capturing the larvae shaken off the plants. In the "Gardeners' Chronicle" for Sept. 23, 1882, (Enectra Pilleriana and Lobesia reliquana are noticed and figured by Professor Westwood; and, in the same newspaper, a month later, still another insect-foe is added: this is Ditula angustiorana (also called Tortrix angustiorana). The last-named is nearly related to Lobesia reliquana, but is larger. The fore wings measure from 1/2in. to 3/4in. in span, being ochreous in the males, and reddish-brown in the females; in both sexes, the wings show a darker patch at the base, a chestnut-brown patch slanting from the middle of the wing to the hinder angle, and darker spots irregularly scattered over the outer half of the wing, the most conspicuous of these being a triangular spot on the front border. The larvae have been found living on most fruit-trees, as well as on Privet, Hawthorn, and other shrubs; and within the past few years they have been discovered in ripened grapes in English vineries. They also feed on the Vine leaves, but not in such numbers as to seriously injure the plants in this way. Though abundant in many parts of England, Ditula angustiorana usually feeds on a variety of food-plants in preference to Vines.
Among the Tineina (see Moths) there are few species that are dangerous to Vines. Of one small Moth (Antispila Pfeifferella) the larvae, which usually feed on the leaves of Dogwood, sometimes mine in the Vine leaves, and, when about to become pupae, form flat cases composed of two pieces cut out of the leaves, and attach them to the leaves or branches. The pupae lie protected in the cases till the emergence of the Moths. The fore-wings of the latter reach only about 1/3in. in span; they are brown, with a coppery or golden gloss, and near the middle they are crossed by two narrow, yellow bands, the outer of which is broken in the middle. The injury done to the leaves by this species is seldom noticeable, though the Moth is not rare in England.
Treatment. This varies with the habits of the larvae that are doing the harm. Hand-picking is a sufficient remedy against the larvae of Hawk Moths, and the groups of larvae of Naenia typica. It is the only efficient method against Leaf-miners, such as Antispila; and it must also be resorted to against the larvae of Tortricina, which live inside the young or ripe fruits, or in the clusters, inclosed in webs. The larvae, and the leaves or grapes in which they live, should be destroyed, not merely thrown on the ground. Hand-picking is also of use where the eggs (e.g., of Enectra Pilleriana) are placed in clusters on the leaves. Those larvae that conceal themselves in the soil by day, and emerge from their concealment by night to feed on the shoots and leaves, or that gnaw the bark of the stems and roots, should be combated as recommended under Surface Caterpillars. Such larvae as live in rolled leaves may be collected in sheets or trays laid below the branches, which should be shaken or jarred, to cause the larvae to drop from their concealment. The larvae of some of the Tortricina that injure the Vines and fruits, pass the winter under the loose bark on the stems, and emerge, when the weather becomes milder, to devour the buds, young leaves, and flowers. The pupae of some are protected during winter in similar retreats. It is, therefore, desirable to remove all loose bark, and this can be done in winter by means of a brush of stiff fibres, e. g., of piassaba. All dead leaves and rubbish should also be removed from the surface of the soil, and either consigned to the compost-heap or burned. In the continental vineyards, the Moths are trapped by fires, or by shallow dishes of water, into which they fly. A solution of potassic sulphate (1 per cent), sprayed over the flower-buds about the time the first brood of Moths is on the wing, and over the young fruits when the second brood is ready for egg-laying, has been found to materially lessen the injury to the crop.