Forest Pests: Insects, Diseases & Other Damage Agents

Leafrollers and Fruitworms (Family Tortricidae)

Maier, C.T., C.R. Lemmon, J.M. Fengler, D.F. Schweitzer, and R.C. Reardon. 2004. Caterpillars on the Foliage of Conifers in the Northeastern United States. FHTET-2004-1. Morgantown, WV: USDA Forest Service, Forest Health Technology Enterprise Team; 151 p.

Most of the caterpillars in this large family have a uniform body color and a variably pigmented prothoracic shield and anal plate. The color of the shield or plate often is used to identify species. The caterpillars tend to be slender if they feed externally, and stout if they feed internally. Many of the external feeders rapidly move backward when they are dislodged from their feeding sites or otherwise disturbed. Tortricid caterpillars are medium-sized, varying from 8 to 25 mm in length at maturity. They have a single pair of prolegs on A3 to A6 and A10. Above the anus, most species have an anal comb that is used to eject frass. Members of this family are best distinguished by the arrangement of hairs on their bodies.

Some caterpillars are external feeders that eat buds, leaves, flowers, and seeds. The foliage feeders often roll, crumple, or tie leaves together before eating them. Other species feed internally by mining leaves or by boring into stems, fruit, roots, or other structures. A few change from internal to external feeders during their life. Tortricids, as a whole, have a broad food range, eating most major groups of plants. This family has many economically important species, including the spruce budworm, Choristoneura fumiferana, the oblique-banded leafroller, C. rosaceana, and the codling moth, Cydia pomonella.

The moths of most species have dull coloration and tend to be camouflaged when they are resting. Most adults are small to medium in size. Typically, they are active at night. Chemists have duplicated the sex attractant produced by adult females of some tortricid pests. These attractants have been used in traps to monitor the flight activity of males or have been released in abnormally high concentrations to disrupt mating activity.

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