TYPE HOST DESCRIPTION Boxelder Leafroller Boxelder Adults are ½ inch tan moths; larvae are 1/4 to 3/4 inch, green caterpillars with a dark head. There is one generation per year. Fruittree Leafroller Apple, pear, plum, cherry, raspberry, currant, ash, boxelder, elm, linden, poplar, willow, locust, rose, and oak. Adults are 1/2 to 3/4 inch moths with a mottled, rusty-brown pattern; larvae are 1/4 to 3/4 inch, pale-green caterpillars with a black head. There is one generation per year. Oblique-banded Leafroller Fruit trees and ornamental trees and shrubs. Adults are 3/4 to 1 inch moths with a tan to brown band; larvae are 1/4 - 1 inch, green caterpillars with brown heads. There are two generations per year.

LIFE CYCLE: Our main Montana leafroller, the Fruittree leafroller overwinters as an egg. Eggs hatch into tiny larvae in spring  around mid-May. Larvae feed on leaves for about 30 days and then pupate in a rolled leaf or similar shelter. Eight to 11 days later the adult emerges from the pupa. The moths live only about a week, during which time they mate and lay eggs. They fly in May or June for about 3 weeks. Only one generation occurs each year.

CONTROLS:

Biological:  Several native parasitic insects have provided adequate control of Oblique-banded leafrollers in Wisconsin, including a species of tachinid fly and species of braconid, ichneumonid, and chalid wasps. Spiders, pathogens, and other predators also contributed to oblique-banded leafroller control in a University of Wisconsin study.

Botanical:  Bacillus thuringiensis (Bt-K). Treat newly hatched larvae, before leaves curl. This works best whentemperatures are warm (>50ºF). See Bacillus thuringiensis.