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Home , Bark beetle, Cleridae, Dendroctonus brevicomis, Dendroctonus jeffreyi, Enoclerus lecontei, Ips paraconfusus

Integrated Management for Home Gardeners and Landscape Professionals

Bark beetles, Scolytidae, are now has 20 invasive spe- common pests of conifers (such as cies of bark beetles, of which 10 spe- ) and some attack broadleaf . cies have been discovered since 2002. Over 600 occur in the United The biology of these new invaders is States and Canada with approximately poorly understood. For more informa- 200 in California alone. The most com- tion on these new species, including mon species infesting pines in urban illustrations to help you identify them, (actual size) landscapes and at the wildland-urban see the USDA Forest Service pamphlet, interface in California are the engraver Invasive Bark Beetles, in References. beetles, the red , and the western beetle (See Table 1 Other common -boring pests in Figure 1. Adult western pine beetle. for scientific names). In high elevation landscape trees and shrubs include landscapes, such as the Tahoe Basin clearwing moths, roundheaded area or the San Bernardino Mountains, borers, and flatheaded borers. Cer- the Jeffrey pine beetle and mountain tain wood borers survive the milling Identifying Bark Beetles by their Damage pine beetle are also frequent pests process and may emerge from wood and Signs. The species of attacked of pines. Two recently invasive spe- in structures or furniture including and the location of damage on the tree cies, the Mediterranean pine engraver some roundheaded and flatheaded help in identifying the spe- and the redhaired pine bark beetle, borers and woodwasps. Others colo- cies present (Table 1). On large pines, colonize various Mediterranean pines, nize wood after it has been placed for example, engraver beetles usually which are widely planted in and in structures, such as carpenter ants, attack trees near the top, whereas red around the Los Angeles Basin and the carpenter bees, powderpost beetles, turpentine beetles attack the lower Central Valley. and termites. For more information on portion of the trunk. They can even these other borers, see the Pest Notes colonize near the collar and Cedar and cypress bark beetles attack listed in References. exposed and continue to mine arborvitae, cypress, false cypress, ju- under the bark below ground on the nipers, and redwoods. The fir engraver IDENTIFICATION large roots. Engraver beetles are dark brown, cylindrical, and have a scoop- attacks white and red fir at high eleva- Bark beetle adults are small, cylindri- like depression at the end of the abdo- tion locations. Oak bark and ambrosia cal, hard-bodied about the men that is lined with stout spines. beetles attack oaks and certain other size of a grain of rice. Most species Their presence is indicated by piles broadleaf trees including California are dark red, brown, or black. When of dry boring dust pushed out on the buckeye and oak. A long-time viewed under magnification, their bark surface. Red turpentine beetles antennae are visibly elbowed with the (naturalized) invasive bark beetle are larger than engraver beetles, red- outer segments enlarged and clublike called the shothole borer attacks dam- dish brown, and have a rounded tip to aged branches and trunks of many (Fig. 1). When viewed from above, the the abdomen (Fig. 1). Their presence broadleaved tree species, including head is partly or completely hidden by is indicated by large, pinkish brown fruit trees and English laurel. Two the pronotum (the top of the body part to white pitch tubes (a mixture of pine other invasive species, the European behind the head). Bark beetles have and beetle boring dust that ap- bark beetle and the banded elm strong mandibles (jaws) for chewing. pears on the lower trunk, Fig. 2). bark beetle feed on and vector A buckshot pattern of holes is appar- (Ophiostoma ent on the bark surface of infested Identifying Bark Beetles by their Galler- novo-ulmi). In its native in Asia, branches or trunks where the new ies. Peeling off a portion of infested the banded elm bark beetle reportedly adults have emerged. Larvae of most bark to reveal the winding pattern of also feeds on certain non-elm tree species are off-white, robust, grublike, the beetle galleries (tunnels chewed species. and may have a dark brown head. by adults and larvae) is a good way to

EST OTES Publication 7421 PUniversity of California N Agriculture and Natural Resources November 2008 November 2008 Bark Beetles

Table 1. Bark Beetles Common in California Landscapes Species Trees affected Generations Comments per year Cedar and cypress bark arborvitae, cypress, 1 to 2 tunnels resemble centipede (Fig. 2) on wood surface beetles false cypress and the inner bark; adult feeds on and kills twigs; - ( species) (Chamaecyparis), laying female attracted to trunk of dead or dying trees junipers, and redwood Elm bark beetles elms 2 overwinter as fully grown larvae in bark; shot holes in ( multistriatus, bark indicate damage; lay in limbs and trunk of Scolytus schevyrewi1) injured, weakened, or recently cut elms; spread Dutch elm disease fungi

Engraver beetles pine 1 to 5 overwinter as adults; often make wishbone-shaped ( emarginatus, tunnels; attack pines near the top of the stem Ips mexicanus, , , Ips plastographus) Fir engraver white and red fir 1 to 2 overwinter as larvae; adults excavate deep and long, (Scolytus ventralis) two-armed galleries across the grain of the sapwood

Jeffrey pine beetle Jeffrey pine 1 to 2 attack midtrunk of large trees, from 5 to about 30 ft; ( jeffreyi) make long J-shaped galleries, overwinter as larvae in the inner bark Mediterranean pine engraver pine 3 to 4 infest trunk and large limbs of Mediterranean pines, ( [formerly Ips] especially Aleppo pine (Pinus halepensis) and Italian erosus)1 stone pine (Pinus pinea) pine, frequently on 1 to 2 attack midtrunk of large trees, from 5 to about 30 ft; (Dendroctonus ponderosae) lodgepole and sugar makes long J-shaped galleries, overwinter as larvae in pine the inner bark Oak ambrosia beetles buckeye, oaks, and 2 or more overwinter beneath bark; bleeding, frothy, bubbling ( species); tanbark oak holes with boring dust indicate damage; attack Oak bark beetles stressed trees ( species) Redhaired pine bark beetle pine 2 to 3 believed to prefer roots and lower trunk of declining (Hylurgus ligniperda)1 Aleppo pine and Canary Island pine (Pinus canariensis) Red turpentine beetle pines, rarely in larch, 0.5 to 2 attack lowest 2 to 8 ft. of trunk and the large roots; () , or white fir pitch tubes appear on bark; overwinter as adults and larvae; rarely kill trees Shothole borer English laurel, fruit 2 or more infestation indicated by gumming of woody parts, () trees, hawthorn, and appearance of boring dust, or twig dieback; remove other woody plants and destroy infested parts Twig beetles pine, walnut 2 or more attack lateral shoots and twigs, can mine the pith; ( carmeli, pine species are associated with pitch canker disease Pityophthorus juglandis, transmission; on walnut Pityophthorus juglandis Pityophthorus nitidulus, is associated with Pityophthorus setosus) transmission Western pine beetle Coulter and 2 to 4 attack midtrunk, then spreads up and down; larvae () ponderosa pines feed on inner bark, complete development in outer bark; attack in conjunction with other pests

1 Recently introduced species whose biology and potential impact in California is poorly understood.

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and again in late summer to early fall. After emergence, adults may re-infest the same tree or, in most cases, dis- perse to attack susceptible trees else- where (Fig. 3). Most bark beetle species have two or more generations a year in California, depending on temperature. At warmer locations (such as lower elevations away from the coast), the season of attack is usually longer and beetles have more generations per year in comparison with cooler coastal or high-elevation locations.

DAMAGE AND SIGNS Bark beetles mine the inner bark (the phloem-cambial region) on twigs, branches, or trunks of trees and shrubs. This activity often starts a flow of tree sap in conifers, but some- times even in like elm and walnut. The sap flow (pitch tube) is accompanied by the sawdustlike frass created by the beetles. Frass accumu- lates in bark crevices or may drop and be visible on the ground or in spider webs. Small emergence holes in the bark are a good indication that bark beetles were present. Removal of the bark with the emergence holes often reveals dead and degraded inner bark Figure 2. Signs of bark beetle activity include pitch tubes on the bark surface and sometimes new adult beetles that (lower left), egg galleries (tunnels), and larval mines beneath the bark. Galleries have not yet emerged. Bark beetles filled with boring dust (frass) are shown in black, whereas open portions of gal- frequently attack trees weakened by leries are white. drought, disease, injuries, or other fac- identify individual beetle species. Red in mines much like the western pine tors that may stress the tree. Bark bee- turpentine beetle and western pine beetle. Galleries chewed by larvae tles can contribute to the decline and beetle adults usually pack about 60% of all species are packed with frass eventual death of trees, however only of their egg-laying galleries with a (Fig. 2). a few aggressive species are known to sawdustlike boring dust called “frass,” be the sole cause of tree mortality. whereas engraver beetles maintain LIFE CYCLE In addition to attacking larger limbs, clean, open adult galleries. Red tur- Bark beetle females lay small, oval, some species such as cedar and cy- pentine beetle adults mine out wide whitish eggs just beneath the outer press bark beetles feed by mining cavelike galleries that progress down bark (Fig. 3). After the eggs hatch, twigs up to 6 inches back from the along the stem. Their larvae feed as a the tiny larvae mine galleries that end of the branch, resulting in dead branch out from the egg-laying gal- group in generally the same direction tips. These discolored shoots hang- as the gallery. Western pine beetle lery. At first the larval mines are ing on the tree are often referred to adults tunnel back and forth across very narrow, but they gradually as “flagging” or “flags.” Adult elm the stem in a gallery pattern that looks increase in diameter as the larvae bark beetles feed on the inner bark of like a piece of spaghetti (Fig. 2). Their grow. Pupation occurs within or twigs before laying eggs. If an adult larvae feed individually in mines beneath the bark in enlarged cham- has emerged from cut logs or a portion that lead away from the adult gallery. bers at the ends of the larval tunnels. of a tree that is infected by Dutch elm Engraver beetle adults make shorter, Pupae are usually plump and whit- disease, the beetle’s body will be con- compact gallery patterns that are ish. Adults can emerge at any time of taminated with fungal spores. When made up of 3 to 4 egg galleries emerg- year, if they are fully developed and the adult beetle feeds on twigs, the ing from an open cell in the center the temperatures are high, but emer- beetle infects healthy elms with the (Fig. 2). The larvae feed individually gence is most common in late spring fungi that cause Dutch elm disease.

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Elms showing yellowing or wilting branches in spring may be infected with Dutch elm disease and should be reported to the county agricultural commissioner.

MANAGEMENT Except for general cultural practices that improve tree vigor, little can be done to control most bark beetles once trees have been attacked. Because the beetles live in the protected habitat beneath the bark, it is difficult to con- trol them with insecticides. If trees or shrubs are infested, prune and dispose of bark beetle-infested limbs. If the main trunk is extensively at- tacked by bark beetles, the entire tree or shrub should be removed. Unless infested trees are cut and infested ma- terials are quickly removed, burned, or chipped on site, large numbers of beetles can emerge and kill nearby host trees, especially if live, unat- tacked trees nearby are weakened or stressed by other factors. Never pile Figure 3. Life cycle of the California fivespined ips, an engraver beetle. infested material adjacent to a live tree or shrub. year, the transplanting method, and Avoid the frequent, shallow type of Cultural Control follow-up care. Stresses placed on a watering that is often used for lawns. Tree Selection. Plant only species prop- tree caused by poor planting or plant- A general recommendation is to irri- erly adapted to the area. Learn the ing at the wrong time of year, lack of gate trees infrequently, such as twice a cultural requirements of trees, and proper care afterwards, or the planting month during drought periods. How- provide proper care to keep them of an inappropriate species for the site ever, a sufficient amount of water must growing vigorously. Healthy trees are will increase a tree’s susceptibility to be used so that the water penetrates less likely to be attacked and are bet- bark beetles or wood borers. deeply into the soil (about 1 foot be- ter able to survive attacks from a few low the surface). The specific amount bark beetles. Where bark beetles have Prevention is the most effective method and frequency of water needed varies been a problem, plant nonhost trees. of managing bark beetles and related greatly depending on the site, size For instance, engraver beetles and red wood-boring insects; in most instances of the tree, and whether the tree spe- turpentine beetles do not attack red- it is the only available control. Avoid cies is adapted to summer drought or or atlas cedars. A mixture of injuries to roots and trunks, damage regular rainfall. tree and shrub species in planted land- and soil compaction during construc- scapes will reduce mortality resulting tion activities, and protect trees from Properly prune infested limbs, and from bark beetles and wood borers. sunburn (sunscald) and other abiotic remove and dispose of dying trees so disorders. Irrigation may be impor- that bark- and wood-boring insects do Reduce Tree Stress. Pay particular at- tant during dry summer months in not emerge and attack other nearby tention to old, slow-growing trees, drought years, especially with tree trees. Timing of pruning is important; crowded groups of trees, and newly species that are native to regions avoid creating fresh pruning wounds planted trees in the landscape. Large where summer rain is common. Also, during the adult beetles’ flight sea- nursery stock or transplanted trees, dense stands of susceptible trees son. Do not prune elm trees from notably oaks and pines, can become should be thinned (complete removal March to September or pines during highly susceptible to bark beetles or of some of the trees) to increase the February to mid-October. Do not pile wood borers after replanting. Trans- remaining trees’ vigor and ability to unseasoned, freshly cut wood near planting success depends on the tree withstand an attack. woody landscape plants. Freshly cut species and its condition, appropriate wood and trees that are dying or have tree and site selection, characteristics Irrigate when appropriate around recently died provide an abundant of the planting site, the season of the the outer canopy, not near the trunk. breeding source for some wood-boring

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beetles. Tightly seal beneath thick (10 mil), clear plastic sheets in a sunny location for several months to exclude attacking beetles, and kill any beetles already infesting the wood. To be effective, solar/plastic treatment requires vigilance and careful execu- tion. It is important to keep wood piles small, use high-quality clear plastic resistant to UV (ultraviolet light) deg- radation, and thoroughly seal edges and promptly patch holes to prevent beetles from escaping. For more in- formation on cultural controls, see the publications by Donaldson and Seybold 1998 and Sanborn 1996 in References.

Biological Control When bark beetles attack trees, natural enemies are attracted to feeding and mating bark beetles (Fig. 4). The two main groups of natural enemies are predators and parasites. Predators are more important in regulating bark beetle populations than parasites. Nat- ural enemies are unlikely to save an infested tree, but they can reduce bark beetle population size, thereby reduc- Figure 4. Bark beetles and declining trees produce airborne chemicals that attract ing the number of nearby trees that adult predators and parasites. Peeling back bark on an infested tree often reveals are attacked and killed by bark beetles. the immature stages (eggs, larvae, and pupae) of both bark beetles (shown above The release of predators and/or para- left) and their natural enemies. Predators include various beetles, such as the often abundant species (family , immature stages and adult top sites into sites infested with bark bee- right) that feed mostly on bark beetles and less common groups, such as snake- tles has not been an effective tactic to flies (family Raphidiidae, bottom right) that prey on a variety of insects. Natural suppress bark beetle populations. enemies are unlikely to save an infested tree, but they can reduce bark beetle populations. The following natural enemies attack the western pine beetle, but rarely bark beetles by using attractant specialists if they are interested in this control it: woodpeckers, several pre- in traps, and repellent management option. daceous beetles such as the blackbel- pheromones and other behavioral lied clerid () and a chemicals to deter beetles from valu- Chemical Control trogossitid beetle (Temnochila chlorodia), able trees. Some behavioral chemicals Unless trees are monitored regularly a predaceous fly Medetera( aldrichii), are being used experimentally on an so that bark beetle attack can be de- snakeflies, and parasitic wasps. area-wide basis to protect stands of tected early, any chemical spray ap- forest trees. The interactions among Behavioral Control plication made once the beetles have host trees and beetles and their Bark beetles locate mates and attract aggregated and penetrated the bark pheromones are complex and often or repel other individuals of the same is likely to be too late and ineffective. poorly understood. Researchers species by emitting species-specific Treatment must target the adults by airborne chemicals called pheromones. are refining the reliability of phero- spraying the bark so that beetles are Pheromones are naturally occurring mone-based management techniques. killed when they land on trees and at- chemicals that are widely used as Behavioral chemicals are currently tempt to bore into the bark to lay eggs. baits to monitor bark beetles by at- recommended for use only by special- Chemically treating trees that have tracting them to traps. These baits ly trained professionals familiar been previously attacked will provide are especially important for detecting with bark beetle management. Land- no benefit and could kill beneficial in- invasive species. Professional foresters scape professionals and home gar- sects. Seriously infested trees, or trees have sometimes controlled or sup- deners should consult with local that are dead or dying due to previous pressed small local populations of California Cooperative Extension beetle attacks, cannot be saved with

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insecticide treatments and should be high-pressure spray equipment and vigor and defense of pines. However, removed. Systemic insecticides, mean- experience to effectively treat large if strong spring rains or regular irriga- ing those that are implanted or inject- trees. Protective spraying for bark tion sprinkling of the stem remove the ed through the bark or applied to soil beetles must be done by a licensed insecticidal barrier, a second applica- beneath trees, have not been shown to pesticide applicator. When hiring a tion may be necessary. prevent attack or control populations professional applicator, discuss the of bark beetles. Although new sys- specific pesticide to be used and ef- Red Turpentine Beetle. This beetle is temic products are being investigated, fective timing of the application. Also very common on Monterey pines they are not currently recommended see Pest Notes: Hiring a Pest Control planted in urban landscapes and for bark beetle control. Company in References. The applicator highway corridors within about 100 must use a product with bark beetles miles of the California coast. It is also Circumstances for Effective Use of Insec- listed on the label, and mix and ap- prevalent on most pines that grow ticides. Highly valued, uninfested host ply the formulation following label in the Sierra Nevada, particularly on trees may be protected by spraying directions. Proper application involves pines damaged by . Otherwise their bark with a persistent, registered thoroughly drenching the main trunk, healthy pines often survive attacks insecticide labeled as a preventive exposed root collar near the base by a few individuals of the red tur- spray for bark beetles. Look for signs of the tree, and larger branches (for pentine beetle. Prominent pitch tubes of recent infestation to help decide engraver beetles) with a pyrethroid, on the lower trunk of standing trees whether preventive spraying of nearby, such as Astro or Dragnet, or any of or stumps of recently cut trees nearly lightly attacked or unattacked trees the flowable (EC) formulations of the always indicate the beetle’s presence. may be justified. Spraying a persistent chemical carbaryl to prevent new bark A red turpentine beetle attack likely insecticide on valuable, uninfested beetle infestations. (Note: These prod- indicates that pines are stressed from host trees near infested trees may be ucts are not available to home users.) an unfavorable growing environment, warranted to protect uninfested host The material must be applied before injuries, inappropriate cultural care, trees from bark beetles. However, do the new adults penetrate the bark or that pines are declining from old not substitute preventive sprays for surface of the tree. Regardless of the age. Ensure that planted trees receive proper cultural care. The infestation insecticide used, the applicator should proper care and a good growing envi- status of a tree can be determined by mix only what is needed and dispose ronment to enhance tree survival. inspecting the trunk or limbs for fresh of any excess insecticide by properly pitch tubes or frass; peeling a small following label directions. Western Pine Beetle. This native species portion of the outer bark from the attacks the trunk of ponderosa and trunk or limbs and looking for signs When to Apply Insecticides. Preventive Coulter pines and creates long wind- of adult beetles or larvae; and inspect- treatments must be applied to the tree ing galleries in the phloem. The trunk ing the foliage for yellow or yellow- trunk or branches to kill adults before quickly becomes covered with small green needles or leaves. Frequently they penetrate the bark and lay eggs. pitch tubes as the beetles can be at- the infestation is diagnosed after the Treatment following successful attacks tracted in large numbers (aggregate) beetles have vacated the tree. For ex- and egg laying will not be effective. In in only a few days. Drought-stressed ample, when reddish brown foliage is most cases, the time to apply is in late trees are highly susceptible to attacks observed the tree is dead and the new winter to early spring in warm areas by these bark beetles. Heavily attacked generation of bark beetles has already of the state and late spring in cooler trees invariably die and should be re- emerged from the tree. Fading foliage and higher elevation areas. For most moved as soon as attacks are observed. throughout the tree crown indicates a insecticide treatments associated with Unattacked trees that are particularly dead tree and no insecticide treatment bark beetles listed on the insecticide vulnerable, such as during drought or will be effective. Because each bark label, generally only one application those adjacent to attacked trees, can beetle species attacks only certain tree per year is necessary to provide sea- be protected by watering, if possible, species, spray only healthy trees that son-long control. However, depending and by applying an insecticide to the are susceptible to the beetle species at- on local conditions, the life cycle of outer bark surface before beetles have tacking nearby trees (for example, pine the beetle, and the insecticide used, attacked the tree. bark beetles do not attack oaks and in a few situations a second applica- oak bark beetles do not attack pines) tion may be needed several months Elm Bark Beetles. Elm bark beetles are (Table 1). Insecticide sprays are not rec- later to protect individual trees. For pests because they feed in the phloem ommended against shothole borer and example, in California a single spray of elms and spread the fungus that cedar or cypress bark beetles. applied for red turpentine beetle and causes Dutch elm disease. The fungus engraver beetles around mid-Febru- kills the vascular system of elms, caus- How to Apply Insecticides. Insecticide ary, before adults arrive on new trees, ing foliage to turn yellow and brown products available to home users are should provide enough control for the and then die. Be sure to distinguish not effective for bark beetle control. home gardener or arborist to imple- diseased trees from those damaged by Most home gardeners also lack the ment cultural practices to improve the leaf-chewing caused by elm leaf bee-

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tles (Xanthogaleruca luteola). Chewed Reno: University of Nevada Cooperative Marer, P. J., and M. Grimes. 1995. Forest and leaves turn brown, which, when Extension Fact Sheet FS-98-42. Available Right-of-Way Pest Control. Oakland: Univ. viewed from a distance, resemble dis- online, www.unce.unr.edu/publications/ Calif. Agric. Nat. Res. Publ. 3336. colored leaves caused by Dutch elm files/ho/other/fs9842.pdf. Pest Notes: Wood Wasps disease. If planting elms, choose from Mussen, E. C. 2000. Dreistadt, S. H., J. K. Clark, and M. L. Flint. and Horntails. Oakland: Univ. Calif. Nat. among the many new elm cultivars 2004. Pests of Landscape Trees and Shrubs: An Res. Publ. 7407. that are resistant to both disease and Integrated Pest Management Guide. Oakland: leaf beetles, as discussed in Pest Notes: Univ. Calif. Agric. Nat. Res. Publ. 3359. Paine, T. D., J. G. Millar, and S. H. Dreistadt. Elm Leaf Beetle in References. 2000. Pest Notes: Eucalyptus Longhorned Dreistadt, S. H., D. L. Dahlsten, and A. B. Borers. Oakland: Univ. Calif. Nat. Res. Publ. REFERENCES Lawson. 2004. Pest Notes: Elm Leaf Beetle. 7425. Donaldson, S. G. and S. J. Seybold. 1998. Oakland: Univ. Calif. Nat. Res. Publ. 7403. Thinning and Sanitation: Tools for the Manage- Rust, M., and J. Klotz. 2000. Pest Notes: ment of Bark Beetles in the Lake Tahoe Basin. Dreistadt, S. H. and E. J. Perry. 2004. Pest Carpenter Ants. Oakland: Univ. Calif. Nat. Notes: Clearwing Moths. Oakland: Univ. Res. Publ. 7416. Calif. Nat. Res. Publ. 7477. For more information contact the University Sanborn, S. R. 1996. Controlling Bark Beetles of California Cooperative Extension in your Flint, M. L., ed. 2004. Pest Notes: Carpenter in Wood Residue and Firewood. Sacramento: county. See your telephone directory for Bees. Oakland: Univ. Calif. Nat. Res. Publ. California Department of and Fire addresses and phone numbers. 7417. Protection, Tree Notes 3. Available online, AUTHORS: S. J. Seybold, Pacific Southwest http://ceres.ca.gov/foreststeward/html/ Research Station, USDA Forest Service; T. Lewis, V. 2000. Pest Notes: Wood-Boring treenotes.html. D. Paine, Entomology, UC Riverside; and S. Beetles in Homes. Oakland: Univ. Calif. Nat. H. Dreistadt, UC Statewide IPM Program Res. Publ. 7418. Wilen, C. A., D. L. Haver, M. L. Flint, P. M. TECHNICAL EDITOR: M. L. Flint Geisel, and C. L. Unruh. 2006. Pest Notes: COORDINATION & PRODUCTION: P. N. Galin Lewis, V. 2001. Pest Notes: Termites. Oak- Hiring a Pest Control Company. Oakland: ILLUSTRATIONS: Fig. 1: from R. W. Doane, land: Univ. Calif. Nat. Res. Publ. 7415. Univ. Calif. Nat. Res. Publ. 74125. v E. C. Van Dyke, W. J. Chamberlin, and H. E. Burke. 1936. Forest Insects. McGraw Lee, J. C., R. A. Haack, J. F. Negrón, J. J. Hill; C. M. Dewees; C. M. De- Fig. 2: Fig. 3: Witcosky, and S. J. Seybold. 2007. Invasive wees; Fig 4: Adapted from R. Kliefoth. 1973. Bark Beetles. Newtown Square, PA: USDA Western Pine Beetle: Life Cycle, Chemi- Forest Service, Forest and Disease cal Communication, and Predators. Boyce Thompson Institute for Plant Research, Leaflet 176. Available online, www.na.fs.fed. Southern Forest Research Institute, Jasper, us/pubs/fidls/invasive_bark_beetles/inv_ Tex. Snakefly from R. S. Woglum and bark_beetles.pdf or at the alternate address, E. A. McGregor. 1959. Observations on the www.fs.fed.us/r6/nr/fid/fidls/fidl-176.pdf life history and morphology of Agulla bractea Carpenter (Neuroptera: Raphidiodea: Raphi- diidae). Ann. Ent. Soc. Am. 52:129–141. WARNING ON THE USE OF CHEMICALS Produced by UC Statewide IPM Program, Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations University of California, Davis, CA 95616 given on the container label. Store all chemicals in the original labeled containers in a locked cabinet or shed, away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock. This Pest Note is available on the Pesticides applied in your home and landscape can move and contaminate creeks, rivers, and oceans. World Wide Web (www.ipm.ucdavis.edu) Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens containing fruits or vegetables ready to be picked. Do not place containers containing pesticide in the trash or pour pesticides down sink or toilet. Either use the pesticide according to the label or take unwanted pesticides to a Household Hazardous Waste Collection site. Contact your county agricultural commissioner for additional information on safe container disposal and for the location of the Household Hazardous Waste Collection site nearest you. Dispose of empty containers by following label directions. Never reuse or burn the containers or dispose of them in such a manner that they may contaminate water supplies or natural waterways. This publication has been anonymously peer reviewed for technical accuracy by University of The University of California prohibits discrimination or harassment of any person on the basis California scientists and other qualified profession- of race, color, national origin, religion, sex, gender identity, pregnancy (including childbirth, and als. This review process was managed by the ANR medical conditions related to pregnancy or childbirth), physical or mental disability, medical condition Associate Editor for Urban Pest Management. (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizen- To simplify information, trade names of products ship, or service in the uniformed services (as defined by the Uniformed Services Employment and have been used. No endorsement of named products Reemployment Rights Act of 1994: service in the uniformed services includes membership, applica- is intended, nor is criticism implied of similar products tion for membership, performance of service, application for service, or obligation for service in the that are not mentioned. uniformed services) in any of its programs or activities. University policy also prohibits reprisal or This material is partially based upon work supported retaliation against any person in any of its programs or activities for making a complaint of discrimi- by the Extension Service, U.S. Department of nation or sexual harassment or for using or participating in the investigation or resolution process of Agriculture, under special project Section 3(d), any such complaint. University policy is intended to be consistent with the provisions of applicable Integrated Pest Management. State and Federal laws. Inquiries regarding the University’s nondiscrimination policies may be di- rected to the Affirmative Action/Equal Opportunity Director, University of California, Agriculture and Natural Resources, 1111 Franklin Street, 6th Floor, Oakland, CA 94607, (510) 987-0096.

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