| Western | Mountain | Southern | |||
| Spruce | spruce | Gypsy | pine | pine | |
| Year | budworm | budworm | moth | beetle | beetle |
| million acres | |||||
| 1968 | 1.3 | 5.3 | 0.1 | na | na |
| 1969 | 1.2 | 4.6 | 0.3 | na | na |
| 1970 | 2.0 | 4.0 | 1.0 | na | na |
| 1971 | 1.6 | 4.8 | 1.9 | na | na |
| 1972 | 2.8 | 5.5 | 1.4 | na | na |
| 1973 | 4.2 | 4.4 | 1.8 | na | na |
| 1974 | 10.8 | 5.5 | 0.8 | na | na |
| 1975 | 9.2 | 5.3 | 0.5 | na | na |
| 1976 | 9.1 | 5.8 | 0.9 | na | na |
| 1977 | 10.3 | 6.5 | 1.6 | na | na |
| 1978 | 7.7 | 5.2 | 1.3 | 4.0 | na |
| 1979 | 6.6 | 5.0 | 0.6 | 4.4 | 15.0 |
| 1980 | 6.6 | 4.0 | 5.0 | 4.7 | 12.1 |
| 1981 | 4.5 | 5.5 | 12.9 | 4.7 | 0.9 |
| 1982 | 4.2 | 8.7 | 8.2 | 4.2 | 7.3 |
| 1983 | 6.5 | 11.0 | 2.4 | 3.6 | 11.4 |
| 1984 | 6.1 | 10.6 | 1.0 | 3.3 | na |
| 1985 | 5.2 | 12.8 | 1.7 | 3.3 | 15.5 |
| 1986 | 1.0 | 13.2 | 2.4 | 3.5 | 26.4 |
| 1987 | 0.8 | 8.0 | 1.3 | 2.4 | 13.8 |
| 1988 | 0.3 | 6.1 | 0.7 | 2.2 | 7.9 |
| 1989 | 0.2 | 3.1 | 3.0 | 1.6 | 5.3 |
| 1990 | 0.2 | 4.6 | 7.3 | 0.9 | 4.2 |
| 1991 | 0.1 | 7.2 | 4.2 | 0.6 | 10.7 |
| 1992 | 0.1 | 4.6 | 3.1 | 15.8 | 14.3 |
| 1993 | 0.1 | 0.5 | 1.8 | 0.8 | 10.4 |
| 1994 | 1.0 | 0.5 | 0.9 | 0.4 | 5.3 |
| 1995 | 0.8 | 0.5 | 1.4 | 0.6 | 21.7 |
| 1996 | 0.5 | 0.3 | 0.2 | 0.3 | 7.3 |
| 1997 | 0.4 | 0.4 | (s) | 0.3 | 8.5 |
| 1998 | 0.4 | 0.8 | 0.4 | 0.3 | 6.8 |
Sources: U.S. Department of Agriculture, Forest Service, Forest Insect and Disease Conditions in the United States, 1979-1983 (USDA, FS, Washington, DC, 1985).
--, Forest Insect and Disease Conditions in the United States (USDA, FS, Washington, DC, annual from 1986).
Notes: na = not available. (s) = 47,300 acres; lowest acreage since 1959. Acreage for spruce budworm from 1991 forward includes spruce budworm in Alaska since it is the same species of budworm as in the eastern United States (i.e., it is not the western spruce budworm). Mountain pine beetle data for 1992 includes 15.2 million acres in California not previously reported.
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