UC Agriculture & Natural Resources Forestry

Title Managing Monterey, Ponderosa, and Sugar to Inhibit Red Turpentine

Permalink https://escholarship.org/uc/item/83m8h32h

ISBN 978-1-62711-137-9

Authors Wood, David L McPherson, Brice

Publication Date 2020-11-30

DOI 10.3733/ucanr.8682

Peer reviewed

eScholarship.org Powered by the California Digital Library University of California UC ANR Publication 8682 | July 2020 https://doi.org/10.3733/ucanr.8682 http://anrcatalog.ucanr.edu

Managing Monterey, Ponderosa, and Sugar Pines to Inhibit Red Turpentine Beetles

DAVID L. WOOD, Professor SUMMARY Wood et al. 2003; Wood and Storer 2002; Emeritus, Department of Waters et al. 1985; Wood 1982; Furniss and Environmental Science, Monterey pines, the most widely planted coni- Carolin 1977; Bright and Stark 1973). Bark Policy, and Management, UC Berkeley; fer species in the San Francisco Bay Area, are beetles colonize the cones, branches, limbs, BRICE A. MCPHERSON, vulnerable to attack by red turpentine beetles; trunks, and roots of trees. Specialist, Department of ponderosa pines and sugar pines are likewise The focus of this article, a literature review, Environmental Science, vulnerable. Subsequent infestation by the Cali- is the role that bark beetles play in the mor- Policy, and Management, fornia fivespined can lead to tree mortality. UC Berkeley tality of Monterey pines in California—in Landowners can protect against attacks by red particular, in the San Francisco Bay Area. The turpentine beetles by inspecting trees frequent- article provides management recommendations ly, applying registered pesticides, and pruning to landowners whose mature Monterey pines only between November 1 and mid-February. might be threatened by bark beetles, but the Pruning pines and other conifers in warm recommendations also apply to ponderosa and weather can attract tree-killing bark beetles. sugar pines. Bark beetles’ biology, and their impacts on INTRODUCTION host trees, suggest that insecticides should be applied to prevent mortality caused by bark Monterey (Pinus radiata) is the most beetles. Two insecticides—Dragnet (perme- widely planted conifer species in the San thrin) and Sevin (carbaryl)—are currently Francisco Bay Area. The species is also widely registered by the California Department of planted throughout other low-elevation urban Pesticide Regulation and the U.S. Environmen- areas in California. Native populations of tal Protection Agency (EPA) for protecting old-growth Monterey pine are found in three conifers from infestation by bark beetles. areas on the Central Coast of California: Año Nuevo State Park, the Monterey Peninsula, Four species of bark are associated and Cambria. Ponderosa pine (P. ponderosa) with mortality of Monterey pines in California: is widely distributed throughout forested areas the red turpentine beetle ( val- in the western United States and Canada, with ens), the California fivespined ips (Ips paracon- a northern range from British Columbia to fusus), the Monterey pine ips (I. mexicanus), North Dakota and a southern extent from the and the California pine engraver (I. plastogra- coastal mountains in California to the south- phus). Red turpentine beetles, California pine ern Rocky Mountains. Sugar pine (P. lamber- engravers, and Monterey pine ips are found in tiana) appears in forested areas from southern dead and dying trees in the three native, old- Oregon and northwestern Nevada to Southern growth Monterey pine forests on the Central California. Coast of California. The California fivespined ips is only rarely found in these native forests. More than 170 species of bark beetles are All four species are found in dead and dying found in California’s forests and woodlands Monterey pines that have been planted in Cali- (Vega and Hofstetter 2015; Seybold et al. 2008; fornia’s urban forests (Owen and Adams 2001). UC ANR Publication 8682 | Managing Monterey, Ponderosa, and Sugar Pines to Inhibit Red Turpentine Beetles | July 2020 | 2

Rearing studies of infested Monterey pines INFESTATION BY BARK BEETLES: by Seybold and Wood (unpublished data) SYMPTOMS AND TREATMENT demonstrate that the abundance of the three Ips species mentioned above changes as one moves Red turpentine beetle further from the coastal environment in Marin The red turpentine beetle (fig. 1) attacks pri- County and toward the inland environment marily the trunk (figs. 2 and 3) and exposed in Contra Costa County (Walnut Creek), a roots (fig. 4) of injured and diseased Monterey distance of about 25 miles. Whereas the Cali- pines, but can be found attacking apparently fornia fivespined ips is most abundant in more healthy trees as well. These attacks are indicated inland areas, Monterey pine ips and California by streaming resin and “pitch tubes” that appear pine engravers are most abundant near the on the trunk from the root collar to about 5 or California coast and least abundant in inland, 6 feet above the ground. Pitch tubes are globules low-elevation areas. Jack Kelly Clark Jack Kelly

Figure 1. Adult Dendroctonus valens, the red turpentine beetle.

Figure 3. Appearance of Dendroctonus valens frass on a Monterey pine trunk. Jack Kelly Clark Jack Kelly

Figure 2. Pitch tubes of Dendroctonus valens on a Monterey pine trunk. Figure 4. Pitch tubes of Dendroctonus valens on a Monterey pine root. UC ANR Publication 8682 | Managing Monterey, Ponderosa, and Sugar Pines to Inhibit Red Turpentine Beetles | July 2020 | 3

Table 1. Comparison of red turpentine beetle and California of resin that flow from the entrance tunnel fivespined ips. that the female beetle forms as she penetrates Red turpentine beetle California fivespined ips the outer bark to reach the phloem (food-con- (D. valens) (I. paraconfusus) ducting tissue of a tree). Pitch tubes can be number of 0.5–2 1–5 milky white—or reddish brown when frass generations (bark and phloem fragments and fecal materi- per year al) is extruded from the entrance tunnel (see overwintering adults and larvae adults and larvae fig. 2). Frass may appear as chunky fragments life stage spilling from a bark crevice (see fig. 3). On adult flight Feb. 15–Nov. 1 Feb. 15–Nov. 1 larger trees, attacks can occur for several years period without killing the tree. However, repeated trees infested many pine species, including many pine species, including attacks by red turpentine beetles can result Monterey, sugar, ponderosa, Monterey, sugar, ponderosa, in the death of Monterey pines if trees are lodgepole, and Jeffrey pines lodgepole, and Jeffrey pines subsequently attacked by the California fives- chemical Apply insecticide to prevent If beetles have attacked a tree pined ips (Wood et al., unpublished data). In control attacks by tree-killing beetles; but egg galleries are not pres- use products approved ent, the entire bole (trunk) can forested areas of the Coast Ranges and the for control of bark beetles, be sprayed according to label Sierra Nevada, the western pine beetle (D. following EPA label. Must be instructions. brevicomis) and the mountain pine beetle (D. applied by applicator certified or licensed by the State of ponderosae) infest ponderosa pines previously California. Apply to 2 meters attacked by the red turpentine beetle (Owen (7 feet). et al. 2005; Wood et al. 2003; Furniss and Carolin 1977). To decrease the likelihood of Monterey pine mortality, observations of lower tree trunks should be conducted every 1 to 2 weeks, starting in February and continuing until November 1 (Wood, personal obser- vations in a plantation of Monterey pines in Moraga, California, 1965 to present). If pitch streaming or pitch tubes produced by tunneling red turpentine beetles are observed, the lower trunk can be treated with either Dragnet or Sevin to a height of 2 meters (7 feet) (table 1). California fivespined ips In the San Francisco Bay Area, the California fivespined ips—an engraver beetle—has been observed killing Monterey pines that exhibit pitch tubes produced by the red turpentine beetle (Svihra 1995; Wood et al., unpublished observations). Attacks by the California fivespined ips are indicated by small pitch tubes—or more frequently, by reddish-brown Figure 5. Boring dust marking the entrance tunnel of an frass that is produced by tunneling bark bee- Ips paraconfusus beetle on a pine trunk. tles (fig. 5) and accumulates in bark crevices. Frequent inspection for reddish-brown frass resulting from attacks, found in bark crevices at the base of trees and in spider webs, is recommended. Once California fives- pined ips have initiated galleries, in which UC ANR Publication 8682 | Managing Monterey, Ponderosa, and Sugar Pines to Inhibit Red Turpentine Beetles | July 2020 | 4

eggs are laid, the tree is by ips species. We also hope to interrupt the likely already infested and chemical signaling that likely occurs between probably dead, although these bark beetle species (see below). In urban the foliage may still be Monterey pine forests in California, the red green. Therefore, before turpentine beetle is only rarely associated with deciding to apply an insec- mortality of Monterey pines unless the trees ticide to prevent further have also been attacked by California fives- attacks, a small portion pined ips, a known tree-killing species (per- (1–2 inches) of the outer sonal observation; Wood et al. 2003), or the bark should be removed Monterey pine ips (Owen and Adams 2001). to determine if galleries are present. Galleries are CHEMICAL SIGNALING BETWEEN tunnels (0.20–0.25 inches BEETLE SPECIES in diameter) that are not packed with frass (fig. What is the evidence for chemical signaling 6). If the removed bark between the red turpentine beetle and a does not reveal galleries tree-killing bark beetle? Studies at Blodgett at breast height, a similar Forest Research Station (located in the central examination should Sierra Nevada of California, at 3,400 feet be made at midbole above sea level) showed that over a period Figure 6. Nuptial chamber and (midtrunk) or in the lower egg in niches in gallery walls of Ips of 2.5 years (June 1981 to November 1983), canopy; this is because paraconfusus in phloem. ponderosa pines with pitch tubes produced by I. paraconfusus is known red turpentine beetle attacks had a significantly to kill the tops of larger higher rate of mortality caused by western pine Monterey, ponderosa, and sugar pines (Furniss beetles and mountain pine beetles than trees and Carolin 1977). without these pitch tubes (Owen et al. 2005). If inspection and dissection of a small Trees with the highest number of red turpen- section of bark with reddish boring dust do tine beetle pitch tubes exhibited the highest not reveal the presence of egg galleries, the rec- mortality rate. These results suggest that red ommended treatment is to spray the bole with turpentine beetles produce volatile compounds Dragnet or Sevin to the upper canopy. The that attract western pine beetles and mountain label permits this bole treatment, but due to pine beetles. However, we could not find the likelihood of insecticide drift to nontarget scientific evidence that demonstrates the rela- organisms, this approach should be considered tionship between attacks by the red turpentine carefully. beetle and subsequent mortality of Monterey Treating a large tree is a major project that pines caused by California fivespined ips. requires hydraulic equipment, and insecti- Svihra (1995) demonstrated that formu- cide drift is a major concern. See Fettig and lations of permethrin and carbaryl protected Hilszczański (2015) for discussion of the pro- Monterey pines from red turpentine beetle tection from attacks by bark beetles that may infestation for one year. Both the number of be afforded to conifers by the tree injection of trees infested and the number of attacks per insecticides. Infested trees should be removed tree were greatly reduced by these treatments and either chipped or taken to a composting compared to the controls. However, Svihra did facility. Contact an arborist, cooperative exten- not demonstrate a lower mortality rate caused sion agent, or tree professional for assistance by red turpentine beetles and California five- with identifying bark beetle infestations or spined ips following the insecticide treatments. with insecticide application. Nevertheless, it is reasonable to conclude that By preventing further attacks by the red reducing the attack rate of red turpentine turpentine beetle, we hope to reduce stress on beetles on Monterey pine trees is likely to trees’ defenses and thereby increase resistance lead to a reduced mortality rate caused by red to both red turpentine beetles and infestations turpentine beetles and California fivespined UC ANR Publication 8682 | Managing Monterey, Ponderosa, and Sugar Pines to Inhibit Red Turpentine Beetles | July 2020 | 5

ips, either alone or in combination with pitch red turpentine beetles are found in Monterey canker (a disease caused by the fungus Fusari- pines (Cool and Zavarin 1992). Thus, for all um circinatum). the tree species discussed here, we recommend pruning in winter months: November 1 to RELATIONSHIP BETWEEN BEETLE mid-February. Because of the warmer climate ATTACKS AND PITCH CANKER in Southern California, we suggest treatment with insecticides every 3 months. Pruning Monterey pine mortality caused by pitch pines and other conifers in warm weather can canker was discovered in California in 1986. attract tree-killing bark beetles. For other con- Later studies (see 2001 review by Gordon et trol methods, see Seybold et al. (2008). al.) demonstrated that the first infections of pitch canker cause branch tip mortality in the CULTURAL MEASURES TO MAINTAIN upper canopy, followed by resinous cankers TREE HEALTH on the trunk. Twig beetles (Pityophthorus spp.) and engraver beetles (Ips spp.) were shown The two cultural treatments that have the to vector this fungal pathogen into the small greatest impact on the health of trees planted branches and trunk, respectively. Ips spp. first in urban environments involve the root system killed tops of trees weakened by these infec- and the canopy of the tree. When the tree’s tions and then the entire tree. We noted above root system is removed in areas adjacent to the association, in native forests, between tree sidewalks, driveways, and roadways, the tree mortality and both Monterey pine ips and in effect loses as much as 50 percent of its the California pine engraver—and, in planted support. This lost support can result in tree urban forests, between tree mortality and failure at the root collar or in uprooting of California fivespined ips. In a study of the uncut roots. When the canopy is thinned, on interactions between bark beetles and pitch the other hand, the size of the “sail” is reduced, canker, Owen and Adams (2001) observed that thus reducing resistance to strong winds. “No trees died without concurrent coloniza- Strong winds can break limbs, the canopy tion by bark beetles.” They suggested the use of itself, or the main stem—or uproot the tree, pesticides to control bark beetles. causing tree failure. Both these treatments require experience and good judgment from TIMING OF TREATMENTS arborists. Placement of trees at planting time should Chemicals should be applied just prior to bee- take into account the probable size of the trees tles’ emergence from overwintering galleries in for as long as 50 to 75 years into the future. infested trees—mid-February to mid-March in Tree species is an important variable in antic- coastal California forests. ipating possible tree failure. Periodic inspec- Caution: do not prune conifers after this tions by an arborist are important in judging time period because doing so may release possible dangers from tree failure. volatile compounds that attract beetles to Recommended reading healthy trees. Hobson et al. (1993) identified For further information on the biology and monoterpene compounds in oleoresin of control of bark beetles in California, we rec- ponderosa and sugar pine that were attractive ommend Wood et al. 2003, Waters et al. 1985, to red turpentine beetles. These attractive Progar et al. 2013, and Fettig and Hilszczański compounds were also found in the oleoresin 2015—as well as web resources maintained of three co-occurring (sympatric) nonhost by the UC Agriculture and Natural Resources conifers: white fir, Douglas-fir, and incense Statewide Integrated Pest Management Pro- cedar. We do not know if these compounds gram, ipm.ucanr.edu/PMG/PESTNOTES/ occur in other conifers planted in urban pn7421.html and http://ipm.ucanr.edu/QT/ forests with Monterey pines. However, at least barkbeetlescard.html. two compounds known to be attractive to UC ANR Publication 8682 | Managing Monterey, Ponderosa, and Sugar Pines to Inhibit Red Turpentine Beetles | July 2020 | 6

Acknowledgements subject that we had overlooked. We thank We thank Professor Kenneth Hobson (Depart- Victor Ghavamzadeh (East Bay Tree Service ment of Biology, University of Oklahoma, in Moraga, California) for encouraging us to retired) for his in-depth review of our manu- publish a scientific foundation for recommen- script. Dr. Donald Owen (California Depart- dations to prune in winter months in Northern ment of Forestry and Fire Protection, retired) California. sent us an important published paper on this

REFERENCES

Bright Jr., D. E., and R. W. Stark. 1973. The bark Progar, R. A., N. Gillette, C. J. Fettig, and K. and ambrosia beetles of California (Coleoptera: Hrinkevich. 2013. Applied chemical ecology Scolytidae and Platypodidae). Bulletin of the of the mountain pine beetle. Forest Science California Survey 16. https://essig. 60(3):414–433. https://doi.org/10.5849/ berkeley.edu/documents/cis/cis16.pdf forsci.13-010. Cool, L. G., and E. Zavarin. 1992. Terpene Seybold, S. J., T. D. Paine, and S. H. Dreistadt. variability of mainland Pinus radiata. 2008. Bark beetles: integrated pest Biochemical Systematics and Ecology management for home gardeners and 20(2):133–144. https://doi.org/10.1016/0305- landscape professionals. UC Agriculture and 1978(92)90100-R Natural Resources Publication 7421. http:// Fettig, C. J., and J. Hilszczański. 2015. cecentralsierra.ucanr.edu/files/230149.pdf Management strategies for bark beetles Svihra, P. 1995. Prevention of red turpentine beetle in conifer forests. In F. E. Vega and R. W. attack by Servimol and Dragnet. Journal of Hofstetter, eds., Bark beetles: biology and Arboriculture 21(4):221–224. ecology of native and invasive species. New Vega, F. E., and R. W. Hofstetter (eds.). 2015. Bark York: Elsevier. https://doi.org/10.1016/B978-0- beetles: biology and ecology of native and 12-417156-5.00014-9 introduced species. London: Elsevier. Furniss, R. L., and V. M. Carolin. 1977. Western Waters, W. E., R. W. Stark, and D. L. Wood. forest . U.S. Department of Agriculture, 1985. Integrated pest management in pine- Forest Service, miscellaneous publication bark beetle ecosystems. New York: Wiley 1992. Washington, DC: U.S. Department of InterScience. Agriculture. Wood, D. L., T. W. Koerber, R. F. Scharpf, and Gordon, T. R., A. J. Storer, and D. L. Wood. 2001. A. J. Storer (eds.). 2003. Pests of the native The pitch canker epidemic in California. California conifers. Berkeley: University of Plant Disease 85(11):1128–1139. https://doi. California Press. org/10.1094/PDIS.2001.85.11.1128 Wood, D. L., and A. J. Storer. 2002. Bark beetles Hobson, K. R., D. L. Wood, L. G. Cool, P. R. infesting California’s conifers. Fremontia White, T. Ohtsuka, I. Kubo, and E. Zavarin. 30(3–4):19–25. https://cnps.org/wp-content/ 1993. Chiral specificity in responses by the uploads/2018/03/Fremontia_Vol30-No3and4. bark beetle Dendroctonus valens to host pdf kairomones. Journal of Chemical Ecology Wood, S. L. 1982. The bark and ambrosia beetles 19:1837–1846. https://doi.org/10.1007/ of North and Central America (Coleoptera: BF00983790 Scolytidae), a taxonomic monograph. Great Owen, D. R., and D. Adams. 2001. Impact of pitch Basin Naturalist Memoirs 6. https://www. canker on ornamental Monterey pines in Santa biodiversitylibrary.org/page/7965093#page/7/ Cruz County, California, U.S., 1987–2000. mode/1u. Journal of Arboriculture 27(6):298–305. Owen, D. R., D. L. Wood, and J. R. Parmeter. 2005. Association between Dendroctonus valens and black stain root disease on ponderosa pine in the Sierra Nevada of California. The Canadian Entomologist 137(3):367–375. https://doi. org/10.4039/n04-084 UC ANR Publication 8682 | Managing Monterey, Ponderosa, and Sugar Pines to Inhibit Red Turpentine Beetles | July 2020 | 7

To order or obtain UC ANR publications and other products, To simplify information, trade names of products have been visit the UC ANR online catalog at https://anrcatalog.ucanr.edu/ used. No endorsement of named or illustrated products is or phone 1-800-994-8849. Direct inquiries to intended, nor is criticism implied of similar products that are not mentioned or illustrated. UC Agriculture and Natural Resources Publishing An electronic copy of this publication can be found at the UC 2801 Second Street ANR catalog website, http://anrcatalog.ucanr.edu/. Davis, CA 95618 This publication has been anonymously peer Telephone 1-800-994-8849 reviewed for technical accuracy by University E-mail: [email protected] of California scientists and other qualified ©2020 The Regents of the University of California. This professionals. This review process was managed by UC ANR work is licensed under the Creative Commons Attribution- Associate Editor for Natural Resources William Stewart. NonCommercial-NoDerivatives 4.0 International License. To web-7/20-LC/SO view a copy of this license, visit https://creativecommons.org/ licenses/by-nc-nd/4.0/ or send a letter to Creative Commons, Warning on the Use of Pesticides PO Box 1866, Mountain View, CA 94042, USA. Pesticides are poisonous. Some pesticides are more toxic than others and present higher risks to people, nontarget organisms, Publication 8682 and the environment. A pesticide is any material (natural, ISBN-13: 978-1-62711-137-9 organic, or synthetic) used to control, prevent, kill, suppress, https://doi.org/10.3733/ucanr.8682 or repel pests. “Pesticide” is a broad term that includes insecticides, herbicides (weed or plant killers), fungicides, The University of California, Division of Agriculture and rodenticides, miticides (mite control,) molluscicides (for Natural Resources (UC ANR) prohibits discrimination against snails and slugs), and other materials like growth regulators or or harassment of any person in any of its programs or activities antimicrobial products such as bleach and sanitary wipes that on the basis of race, color, national origin, religion, sex, gender, kill bacteria. gender expression, gender identity, pregnancy (which includes pregnancy, childbirth, and medical conditions related to Always read and carefully follow all precautions and directions pregnancy or childbirth), physical or mental disability, medical provided on the container label. The label is the law and failure condition (cancer-related or genetic characteristics), genetic to follow label instructions is an illegal use of the pesticide. information (including family medical history), ancestry, Store all chemicals in the original labeled containers in a locked marital status, age, sexual orientation, citizenship, status cabinet or shed, away from food or feeds, and out of the reach as a protected veteran or service in the uniformed services of children, unauthorized persons, and . Never place (as defined by the Uniformed Services Employment and pesticides in food or drink containers. Consult the pesticide Reemployment Rights Act of 1994 [USERRA]), as well as state label to determine active ingredients, correct locations for use, military and naval service. signal words, and personal protective equipment you should wear to protect yourself from exposure when applying the UC ANR policy prohibits retaliation against any employee material. or person in any of its programs or activities for bringing a complaint of discrimination or harassment. UC ANR Pesticides applied in your garden and landscape can move policy also prohibits retaliation against a person who assists through water or with soil away from where they were applied, someone with a complaint of discrimination or harassment, or resulting in contamination of creeks, lakes, rivers, and the participates in any manner in an investigation or resolution of a ocean. Confine pesticides to the property being treated and complaint of discrimination or harassment. Retaliation includes never allow them to get into drains or creeks. Avoid getting threats, intimidation, reprisals, and/or adverse actions related to pesticide onto neighboring properties (called drift), especially any of its programs or activities. onto gardens containing fruits or vegetables ready to be picked. UC ANR is an Equal Opportunity/Affirmative Action Do not place containers with pesticide in the trash or pour Employer. All qualified applicants will receive consideration pesticides down the sink, toilet, or outside drains. Either use all for employment and/or participation in any of its programs or the pesticide according to the label until the container is empty activities without regard to race, color, religion, sex, national or take unwanted pesticides to your local Household Hazardous origin, disability, age or protected veteran status. Waste Collection site. Contact your county agricultural commissioner for additional information on safe container University policy is intended to be consistent with the disposal and for the location of the Hazardous Waste Collection provisions of applicable State and Federal laws. site nearest you. Follow label directions for disposal of empty Inquiries regarding the University’s equal employment containers. Never reuse or burn the containers or dispose opportunity policies may be directed to: Affirmative Action of them in such a manner that they may contaminate water Compliance and Title IX Officer, University of California, supplies or natural waterways. Agriculture and Natural Resources, 2801 Second Street, Davis, CA 95618, (530) 750-1343. Email: titleixdiscrimination@ ucanr.edu. Website: https://ucanr.edu/sites/anrstaff/Diversity/ Affirmative_Action/.