The light brown apple moth (LBAM), Epiphyas postvittana (Tortricidae), is a native pest of Australia and is now widely distributed New Zealand, the United Kingdom, Ireland, and New Caledonia. Although it was reported in Hawaii in the late 1800s, a recent LBAM detection in California is the first on the United States mainland. USDA confirmed the detection of LBAM in Alameda County, California on March 22, 2007.
LBAM is of particular concern because it can damage a wide range of crops and other plants including California’s prized cypress as well as redwoods, oaks and many other varieties commonly found in California’s urban and suburban landscaping, public parks and natural environment. The list of agricultural crops that could be damaged by this pest includes grapes, citrus, stone fruit (peaches, plums, nectarines, cherries, apricots) and many others. The complete “host list” contains well over 1,000 plant species and more than 250 fruits and vegetables.
The adult insect is a moth about 10 mm long when resting with the wings folded in a characteristic bell shape. Coloring is variable but they are generally yellowish-brown with darker brown markings on the forewings. The females often have a dark spot on the hind margin of the forewing. Females can lay eggs between six and 10 days after moth emergence, depending on the temperature. Eggs are laid in masses on the upper surface of any smooth-leaved host plants. The eggs are flat, and with a pebbled surface and take from five to more than 30 days to hatch, depending on the temperature.
The newly hatched larvae (caterpillars) are very tiny, with a pale yellow-green body and a pale brown head. Early instar larvae wander actively over plant surfaces and may suspend themselves from a fine silken thread until they find a suitable feeding site. The young larvae prefer the underside of leaves and usually start to feed adjacent to a vein where they spin a protective cover of fine webbing. The pupa (chrysalis) is at first green, but soon becomes brown after rapidly hardening, and then darkens during development. The pupa is typically found in a thin-walled silken cocoon between two leaves webbed together, and is usually 10-15 mm long; the female pupae are larger than those of the male. Males and females can be distinguished by examining the pupa from the lower surface.
There are many native tortricids that can be confused for the LBAM. Adult moths must be identified by a qualified entomologist. Larval stages cannot be reliably identified using morphological characters. If you suspect the presence of LBAM, please notify your state department of agriculture or the State Plant Health Director's Office of USDA, APHIS, PPQ.
Last Modified: January 21, 2011