Foray - 48B

Foray® 48B is an aqueous suspension formulation of Bacillus thuringiensis subsp. kurstaki (Btk strain ABTS-351); with a potency of 10,600 Cabbage Looper Units [CLU] per milligram). (This is equivalent to 48 CLU per US gallon, or 12.7 CLU per liter.) Foray 48B was specifically developed to protect forests from harmful defoliation caused by destructive caterpillar pests. Btk is a unique, naturally occurring bacterium that affects only caterpillars and, because of the unique chemistry of the caterpillar’s gut, Foray 48B Btk is highly selective in its activity. It has minimal environmental impact and it will not harm other types of insects, fish, birds or mammals.

Caterpillars must ingest Foray 48B for it to be effective. When forest health professionals determine the timing is right, certified applicators apply Foray 48B to caterpillar-infested trees and forests. Shortly after Foray 48B is eaten, it causes a reaction in the caterpillar’s gut; the caterpillar quickly stops feeding, the gut ruptures and the caterpillar dies within a day or two.

Foray 48B can be applied either neat (undiluted) or diluted with water depending on program needs and application criteria; it should always be applied according to label directions for best results. Timing of Foray 48B spray is critical as well as good spray coverage. As caterpillars do not hatch and develop all at the same time, sometimes a second application may be required. Foray 48B is more effective on younger caterpillars, so more than one application may be needed to control later emerging caterpillars. A second spray may also be required when caterpillar populations are extremely high. Various caterpillar species have varying levels of susceptibility to the Btk toxins; consequently there is a wide range of dosages identified on the label to ensure that effective control of the target species is obtained. (See below)

Foray 48B has been certified for use in Certified Organic Production under the National Organic Program (NOP) and it is also listed by the Organic Materials Review Institute (OMRI).

Suggested Rate Range for Control of Forest Pests (U.S. label rates are used as an example.)  US and Canadian labels are included below (see Downloads); please contact your local supplier for an in-country label.

Crop

Pest

Rate1 (oz/acre)

Dosage1 (CLU/acre)

Rate1 (l/ha)

Dosage1 (CLU/ha)

Forests, Shade Trees, Ornamentals, Shrubs, Sugar Maple Trees, Orgnamental Fruit, Nut & Citrus Trees2

Gypsy Moth & Asian Gypsy Moth 
Elm Spanworm

21 -107

8 - 40

1.5 – 7.8

20 – 99

Spruce Budworm
Browntail Moth
Douglas Fir Tussock Moth
Coneworm
Buck Moth

21 – 80

8 - 30

1.5 – 5.8

20 – 74

Tussock Moth
Pine Butterfly
Bagworm
Leafroller
Tortrix
Mimosa Webworm
Tent Caterpillar
Jackpine Budworm
Blackheaded Budworm
Saddled Prominent
Saddleback Caterpillar
Eastern & Western Hemlock Looper
Organgestriped Oakworm
Satin Moth

16 - 43

6 - 16

1.2 – 3.1

15 – 40

Redhumped Caterpillar
Spring & Fall Cankerworm
California Oakworm
Fall Webworm

11 - 31

4 - 8

0.8 – 2.3

10 – 20

Special Instructions
1 Use the higher recommended rates on advanced larval stages or under high density larval populations
2 In treating Gypsy Moth infected trees and shrubs in urban, rural, and semi-rural areas, exposure of non-target vegetation including, but not limited to, native and ornamental species and food or feed crops is permitted.

Downloads (pdf)