Plant Industry - Light Brown Apple Moth

Light Brown Apple Moth   

Epiphyas postvittana (Walker)  

The light brown apple moth (LBAM), Epiphyas postvittana (Walker), is a highly polyphagous pest that attacks a wide variety of fruits, trees and other plants. This species has a relatively restricted geographic distribution, found only in parts of Europe and Oceania. The pest is a native of Australia but has successfully invaded other countries. It has been determined that the establishment of this pest in the United States would have a severe effect on U.S. agriculture and natural ecosystem. Unfortunately, it has become established in California with seventeen counties now under quarantine. The quarantine areas consists of counties surrounding San Francisco Bay and extending southward along the coast to and including Los Angeles County.

Distribution

Epiphyas postvittana is found in northern Europe, southern Australia, New Zealand, and Hawaii. The climate within its range can be generally characterized as temperate, dry, or tropical. Based on climate zones within the US, it is estimated that approximately 80% of the continental US may be climatically suitable for the establishment of LBAM. Epiphyas postvittana has a host range in excess of 120 plant genera in over 50 families with host preferences in the Compositae, Leguminosae, Polygonaceae, and Rosaceae. Some of the host plants include: apple (Malus domestica, Malus spp.), blackberry and raspberry (Rubus spp.), blueberry (Vaccinium sp.), Brassica spp., butterfly bush (Buddleia sp.), camellia (Camellia japonica), citrus (Citrus spp.), Clematis sp., clover (Trifolium spp.), euonymus (Euonymus spp.), Forsythia sp., grape (Vitis sp.), hawthorn (Crataegus spp.), ivy (Hedera helix), walnut (Juglans sp.), honeysuckle (Lonicera spp.), alfalfa (Medicago sativa), oak (Quercus spp.), Virginia creeper (Parthenocissus quinquefolia), peach (Prunus persica), pear (Pyrus sp.), pepper (Capsicum spp.), Photinia sp., Pittosporum sp., pine (Pinus spp.), potato (Solanum tuberosum), rose (Rosa spp.), strawberry (Fragaria sp.), tomato (Lycopersicum spp.), viburnum ( Viburnum sp.), and willow (Salix sp.).

Description LBAM eggs are pale green and are laid in flat, overlapping masses resembling fish scales on the upper surface of the leaves (Fig. 1).

After hatching, the larvae pass through six instars. Young larvae are tiny (a few millimeters long) with a yellow-green body and brown head. At maturity, larvae are 10-18 mm long and green in color (Fig. 2).

The LBAM has up to four generations a year in Australia. Females have a wingspan of about 2 cm. The forewings are a yellowish-brown with less distinct markings than the male. Males are much smaller than females. The forewings of the males are yellowish-brown at the base of the wing with darker, reddish-brown markings toward the tip (Fig. 3). There can be considerable variation in the markings.

Caterpillars damage the plant by feeding on the leaves, buds, shoots, and fruit. Young larvae feed under silken shelters (Fig. 4).

Older larvae tend to roll leaves together (Fig. 5)

The greatest economic impact comes from larval feeding on the fruit. Quite often this feeding causes irregular brown areas on the surface. Occasionally, the larvae enter the fruit to feed (Fig. 6).

Figure 6. Larva of LBAM entering calyx end of an apple.