Table Of Content

Historic, Archive Document Do not assume content reflects current scientific knowledge, policies, or practices. ~— Yes 2 Roe a, ———— 1 y cas ; fer. < PS wll a ew 7 2 7 ad d ese pie wage ae ee ne ee { 4 i ' 2) "Ye a. Oe ‘ —, : ' | Ly { i ‘ ‘ os 1 , 2 * . i ’ nd “ ] ' ’ : - r a é i A j £5- i>e - " ', " :’ "ia +h% .. @ ‘ a3l e ue 4 + 5 7 a oe, a7 fi * it ‘ ® ® : ‘ a:w aae7 oe .S oat ~ eoer : B ae - gt S t| iy » 7 4 , L¢ ° cy } ¢ ‘ - y‘ = )= air: ae re Jaa:ae ge -r i v.* al=. v)e- +a % ? 7 : : eao e i ovn “) *s - ‘ L Sil aea . = : ; = ~ ai ; ¢ 1S) y - bs al - 7 a 1995 Forest sae Insect and s Disease Conditions } ee) Intermountain Region noige nininvoniisjnl a To | 7¥0 Belignw 2 tonht6.). 2 inistas0l, JT weleH 4 FOREST HEALTH PROTECTION INTERMOUNTAIN REGION Regional Office 324 - 25th Street Ogden, Utah 84401 (801) 625-5257 FTS (801) 625-5257 FAX (801) 625-5127 William W. Boettcher Acting Assistant Director Dave Baumgartner Pesticide Coordinator Boise Field Office 1750 Front Street, Room 202 Boise, Idaho 83702 (208) 364-4220 FAX (208) 364-4111 Dayle D. Bennett Field Representative James T. Hoffman Pathologist Ralph W. Thier Entomologist Julie C. Weatherby Entomologist Joy C. Roberts Computer Analyst K. Andrew Knapp Remote Sensing Specialist Philip J. Mocettini, Jr. Biological Technician Richard L. Halsey GIS Specialist Thomas N. Barbouletos Forester Brian R. Gardner Biological Technician/ Office Manager Linda R. Spillers Computer Assistant Ogden Field Office 4746 South 1900 East Ogden, Utah 84403 (801) 476-9720 FAX (801) 479-1477 Leon LaMadeleine Plant Pathologist/ Field Representative John A. Anhold Entomologist Dawn E. Hansen Entomologist A. Steven Munson Supervisory Entomologist John C. Guyon Plant Pathologist Valerie L. DeBlander Forestry Technician Gary J. Otwell Biological Technician Alan D. Dymerski Forestry Technician Nancy P. Wright Computer Assistant The policy of the United States Department of Agriculture Forest Service prohibits discrimination on the basis of race, color, national origin, age, religion, sex, or disability, familial status, or political affiliation. Persons believing they have been discriminated against in any Forest Service related activity should write to: Chief, Forest Service, USDA, P.O. Box 96090, Washington, DC 20090-6090 iv TABLE OF CONTENTS Subject Page “feed tsf ate cient “0 Sorel Summary of Conditions ‘Status of Insect Conditions Status ofS teman d Branch Diseases ‘Status of Root Diseases ‘Status ofF oliage Diseases 10 hire ofN iecy reins i: 1 i 2: | it ‘Special Project Update | p45) 25 Recent Publications TABLES AND FIGURES Page TABLES Number of trees killed and acres affected by bark beetles on National Forests of Region 4 during 1995 as determined by aerial detection surveys. 11 Status of mountain pine beetle-caused mortality by state during 1595" 2 Status of spruce beetle-caused mortality by state during 1995. 12 Status of Douglas-fir beetle-caused mortality by state during 1995. 13 Status of western pine beetle/Jps-beetle caused mortality by state during 1995. 13 Status of Jeffrey pine beetle-caused mortality by state during 1995. 14 Status of subalpine fir mortality complex by state during 1995. 14 Status of fir engraver beetle-caused mortality by state during o>) fe) Number of acres aerially surveyed by administrative area during 199%. 16 FIGURES Trees killed by bark beetles in Region 4 between 1981 & 1995. 17 Acres defoliated by western spruce budworm & Douglas-fir tussock moth in Region 4 between 1960 & 1995. iM Tree mortality associated with mountain pine beetle and Jeffrey pine beetle in Region 4 - 1995 aerial detection surveys. 18 Tree mortality associated with spruce beetle in Region 4 - 1995 aerial detection surveys. 19 Tree mortality associated with Douglas-fir beetle in Region 4 - 1995 aerial detection surveys. 20 Tree mortality associated with western pine beetle and Jps beetle in Region 4 - 1995 aerial detection surveys. PN Tree mortality associated with fir engraver beetle and subalpine fir mortality complex in Region 4 - 1995 aerial detection surveys. Z2 INTRODUCTION This report summarizes the status of forest insect and disease activity in the Intermountain Region, comprising parts of Idaho, Utah, Nevada, Wyoming and California. Insect status is based largely on annual aerial detection surveys conducted over 14,000,000 acres of forested lands. Disease status is based largely on ground observations and surveys. General insect and disease information is summarized in the Summary of Conditions. Numbers of trees killed by major bark beetles and affected acreages are displayed in Tables 1 through 8. Acres surveyed, by administrative area, during 1995 are summarized in Table 9. Figure 1 depicts the number of trees killed by bark beetles in Region 4 between 1981 and 1995. Figure 2 depicts acres defoliated by Douglas-fir tussock moth and western spruce budworm in Region 4 between 1960 and 1995. General location of major insect activity is shown in Figures 3 through 7. The Special Project Update summarizes on-going studies conducted by Forest Health Protection in cooperation with other Regions, USFS Research, and universities. Recent publications are listed to assist the reader in locating recent pest information of interest. SUMMARY OF CONDITIONS Region-wide, mountain pine beetle caused tree mortality increased in southern Idaho, Utah, and Wyoming from 24,200 trees in 1994,to 41,700 trees in 1995. The largest outbreaks are located on the Dixie, Fishlake, and Manti-LaSal National Forests in Utah, and on the Sawtooth National Recreation Area and Salmon National Forest in southern Idaho. The largest increase in mortality occurred in whitebark and lodgepole pine. Ponderosa pine mortality increased only on the Dixie National Forest. Recorded spruce beetle mortality decreased in Idaho and Utah. Region-wide, 28,000 dead trees were recorded in 1995 compared to 45,200 in 1994. Decreases in tree mortality in Idaho were attributed to loss of host type due to past outbreaks and extensive wildfire. Recorded mortality on the Dixie National Forest, in Utah, significantly increased while mortality on the Manti-LaSal National Forest, also in Utah, decreased. Populations on these two National Forests still remain at epidemic levels. Douglas-fir mortality, caused by Douglas-fir beetle infestation, decreased from previous levels with 48,500 trees killed in 1995 compared to 54,500 trees in 1994. Decreases in mortality occurred in Idaho and western Wyoming, while mortality increased in Utah. The largest outbreaks are located on the Boise and Sawtooth National Forests in Idaho, and on the Manti-LaSal, Uinta, and Wasatch- Cache National Forests in Utah. Western pine beetle mortality increased slightly from 6,300 killed in 1994, to 16,000 trees in 1995. Mortality is located primarily on the Boise and Payette National Forests in southern Idaho. Pine engraver beetle activity was frequently associated with western pine beetle infestation. A complex of western balsam bark beetle, twig beetle, secondary bark beetle, wood borer, engraver beetle, environmental conditions, and disease pathogens continues to damage and kill subalpine fir throughout the Region. Mortality levels increased in 1995 with 418,800 dying trees observed, while in 1994, 272,900 trees were killed. Mortality throughout the host type affects trees of all size Classes. Fir engraver beetle mortality decreased in Idaho, Nevada, and Utah. Region-wide, 140,700 true fir trees were killed in 1995 compared to 180,500 trees in 1994. Much of this decrease is attributed to a decline in activity on the Boise and Payette National Forests in Idaho. Large outbreaks are located on the Toiyabe National Forest in Nevada, and the Uinta and Manti-LaSal National Forests in Utah. Foliage diseases of Populus species were epidemic in 1995, probably because of prolonged cool, moist weather extending into late June. Rust fungi in the genus Melampspora infected aspen, cottonwoods, and willows throughout their host ranges in both forests and residential areas of southern Idaho and northern Utah. Defoliation by the fungus Marssonina was common throughout Utah. In eastern Idaho, cedar apple rust, caused by an undetermined species of Gymnosporangium, caused a leaf spot on residential apple trees in Challis and Salmon, and to Amelanchier throughout the range of serviceberry in eastern Idaho. No significant defoliator activity was observed during 1995.