Appearance

Adults are typically yellow-brown in color. Females are slightly larger than males, with a wingspan of 7-13 mm across. Males tend to be more easily identifiable due to their darker brown forewings. The wings usually are dark brown in color, but with females they often vary and are less prominent.

Behavior & Diet

The light brown apple moth feasts on crops and ornamental plants. It has been detected in California, but originated in Australia. It has become a well-known pest in the United Kingdom, Netherlands, Sweden, Hawaii, New Caledonia and New Zealand. The moth has a very broad host range and a keen ability to survive in a variety of climates, which makes it more difficult to control.

These moths have been known to feed on more than 500 different plant species. Some of the most common host plants are alfalfa, apple, blackberry, raspberry, peach, broccoli, cabbage, clover, cottonwood, grape, potatoes, willow and conifer. When feeding, they can easily damage, kill or affect the appearance of plants.

Reproduction

When females are two to three days old, oviposition begins and can last up to 21 days. Female moths lay their eggs en masse on fruit or leaves – they have been observed to lay more than 1,000 eggs at a time, but typically lay 100 to 500 – and the eggs hatch within 30 days. Multiple generations can emerge in a single year, producing large populations of adult moths. Each egg is approximately 1 mm in size. The egg masses are small and flat and range in color from green to brown.

Signs of Infestation

Common signs of an infestation include egg masses, the webbing of young larvae on the bottom of leaves, rolled leaves or brown areas on the surface of fruit. Since the eggs are so small, it is very difficult to detect them on the host plants. Young larvae typically feed under silken shelters; however, older larvae tend to weave leaves together to shelter themselves.