Forest Health Protection Report

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1 USDA Forest Service Southwestern Region Forest Health Protection Arizona Zone AZ-FHP Forest Health Protection Report Evaluation of bark beetle activity and impacts within the Wallow Fire Alpine and Springerville Ranger Districts Apache-Sitgreaves National Forest December 4, 2013

2 1 Evaluation of bark beetle activity and impacts within the Wallow Fire, Alpine & Springerville Ranger Districts, Apache-Sitgreaves National Forest INTRODUCTION Joel McMillin, Entomologist John Anhold, AZ Zone Leader This report provides an update on bark beetle activity following the 2011 Wallow Fire that occurred across the Alpine and Springerville Districts of the Apache-Sitgreaves National Forests. During summer of 2013, Joel McMillin worked with Forest personnel to monitor bark beetle activity and populations within the Wallow Fire perimeter. In addition, John Anhold and Joel evaluated bark beetle-caused impacts during mid-september in developed recreation sites and Mexican spotted owl Protected Activity Centers (MSO PACs). Some of these areas have been treated with an anti-aggregation pheromone (MCH) for Douglas-fir beetle (Dendroctonus pseudotsugae). Results of these bark beetle monitoring efforts and evaluations of 2013 MCH treatments are presented. A description of potential treatments and recommendations to mitigate future beetle-caused impacts in these areas is provided. Previous reports provide information on the relationship between fire-damaged conifers and susceptibility to bark beetle attack as well as evaluation of pheromone treatments in BARK BEETLE IMPACTS IN DEVELOPED RECREATION SITES Campground (CG) trees are continually under stress from many years of soil compaction caused by foot and vehicle traffic, roots severed for pipelines and other facility construction, deprivation of water and nutrients under pavement, as well as competition with other trees in high tree density conditions. Recent drought, nearby wildfire effects, and dwarf mistletoe infection contribute added stressors which predispose trees to mortality by bark beetle attack. During our visit to the Forest, current and potential bark beetle activity was evaluated Figure 1. Large diameter Douglas-fir attacked by Douglas-fir beetle at Apache Trout CG (left) and Douglas-fir beetle infested trees in MSO PAC south of Alpine (right); note the small transparent crowns, dwarf mistletoe infection and basal scorch.

3 2 at selected recreation and administrative sites. Listed below are observations made at these recreation sites. Big Lake Recreation Complex. As stated in last year s report, due to the nature of stand conditions (i.e., tree size and density of conifers, dwarf mistletoe infection levels) plus proximity to the fire, most of the campgrounds at Big Lake were considered highly susceptible to bark beetle attack in the near future. All of the campgrounds, administrative sites, and many intercampground areas were treated with MCH to protect Douglas-fir and spruce trees in No current Douglas-fir beetle activity was observed in areas treated with MCH in Likewise there was very limited tree mortality caused by bark beetle species on other conifers in Our ground surveys in September 2013 found bark beetle activity present in all of the developed recreation and administrative sites; however, the amount of tree mortality varied widely across the sites. In addition, several bark beetle species were causing impacts. In particular, all conifer species (Douglas-fir, southwestern white pine, ponderosa pine, Engelmann and blue spruce) present at Rainbow CG experienced recent bark beetle-caused tree mortality (Figure 2). The significant increase in mountain pine beetle (D. ponderosae) attacking southwestern white pine at Rainbow CG was somewhat unexpected as very few infested trees were identified within the immediate area in previous years. Other Big Lake sites were impacted to a lesser degree. There was one notable pocket of large diameter Douglas-fir trees that had been attacked near the entrance to the Apache Trout (Figure 1). There was also considerable spruce mortality caused by the blue spruce engraver (Ips hunteri); widespread mortality was observed throughout the Big Lake area (Figure 3). Although both blue and Engelmann spruce were being affected, intermediate-sized blue spruce trees infected with dwarf mistletoe seemed to be the trees primarily being attacked. Subsequent to our surveys, a more thorough survey and marking of infested trees was conducted by Forest personnel in early November. More than 600 current infested trees (all tree species combined) were tallied across 300 acres. Figure 3. Blue spruce mortality caused by blue spruce engraver beetle near the Big Lake Recreation Complex on the Apache-Sitgreaves National Forest, Arizona. In 2013 the Forest had a limited supply of MCH bubble capsules to treat developed sites at Big Lake. Bubble capsules were used on a grid pattern at Grayling, Brookchar and Cutthroat campgrounds plus around storekeeper s residence at Big Lake. The individual tree protection method of MCH deployment was used at the Big Lake VIS, Administrative site, and Apache Trout and Rainbow CGs; however, very few trees were treated at Rainbow CG. MCH

4 3 treatments were effective at preventing new Douglas-fir beetle attacks in most areas and individual trees, although two large Douglas-fir trees (one each at Cutthroat and Brookchar CGs) with heavy dwarf mistletoe infection and small crowns had been attacked. Figure 2. Current bark beetle activity in two campgrounds at Big Lake Recreation Complex on the Apache-Sitgreaves National Forest, Arizona.

5 4 Gabaldon CG. MCH bubble capsules were arranged in grid pattern in both 2012 and No current bark beetle activity was observed at this site with the exception of one corkbark fir tree that was attacked by fir engraver (Scolytus ventralis). Stand conditions (high tree density with large diameter Douglas-fir and spruce) and proximity to adjacent stands with mixed severity burn make this area susceptible to future bark beetle-caused impacts. Hannagan CG & Aker Lake TH. MCH bubble capsules were arranged in grid pattern in both 2012 and The campground has many large diameter Douglas-fir trees that are infected with dwarf mistletoe in addition to numerous large trees being damaged during the Wallow Fire. One tree with these characteristics was found to have been recently attacked by Douglas-fir beetle near the entrance to the campground. Also five white fir trees had been attacked by fir engraver beetles and a scorched Engelmann spruce had been attacked by spruce beetle. BARK BEETLE AND WOOD BORER ACTIVITY IN MSO PACS To determine the level of Douglas-fir beetle and other insect activity within MSO PACs, John and Joel conducted brief walkthrough surveys looking for signs and symptoms of recent attack (fading foliage, boring dust, pitch streaming, pitch tubes, woodpecker activity). Trees sustaining a wide range of fire damage levels were evaluated for insect activity. Within a given PAC, only a subsample of area was surveyed. Therefore, interpretation of survey results should be considered with caution. Time constraints and safety concerns resulted in evaluating only two of the 3 PACs treated with MCH in The third PAC (Bull Canyon) was evaluated based results for the 2013 aerial detection surveys. Six PACs that had been treated in 2012, but not in 2013, were also surveyed. No Douglas-fir beetle activity was observed within two of the three PACs treated with MCH; however, several Douglas-fir trees had been attacked within the Campbell Blue PAC (Table 1). Four of the six untreated PACs had current or nearby Douglas-fir beetle-caused tree mortality. Characteristics of Douglas-fir trees typically being attacked by Douglas-fir beetle included large diameter classes, small live crown ratios, moderate to heavy dwarf mistletoe infection levels and moderate bole scorch (Figure 1). Consistent with observations made in 2012, Douglas-fir mortality in the Double Cienega PAC was caused only by wood borers. Although wood borers associated with conifers are typically only considered secondary insects, certain species of flatheaded borers (Buprestidae) may attack partially scorched Douglas-fir trees and contribute to their mortality. The flatheaded fir borer (Phaenops drummondi) is known, for example, to act as a primary insect attacking drought-stressed and fire-damage Douglas-fir (Furniss and Carolyn 1977). Roundheaded borers (Cerambycidae) were also commonly found beneath the bark of fire-damaged Douglas-fir during recent fires in the area as well as the Wallow Fire. In addition, a limited number of smaller to mid-diameter Douglas-fir trees were being attacked by the Douglas-fir pole beetle (Pseudohylesinus nebulosus) and/or engraver beetles (Scolytus spp.). In addition to Douglas-fir mortality, a complex of bark beetles and wood borers were observed colonizing other mixed conifer tree species in all PACs surveyed. For example, a pocket of more

6 5 than 25 Engelmann spruce trees currently infested with spruce beetle (D. rufipennis) was identified near the Little Colorado River in PAC 6013a. Blue spruce engraver activity was fairly widespread, infesting blue spruce and sometimes Engelmann spruce. Fir engraver populations were also impacting large diameter white fir in several of the PACs. There was also a noticeable increase in mountain pine beetle and pine engraver beetle (Ips species) activity on southwestern white pine scattered throughout the Wallow Fire. In 2012, single tree mortality was typical indicating relatively small populations at that time. During 2013 ground surveys numerous small pockets, usually 2-5 trees, were detected throughout many areas of the Wallow Fire including many of the PACs. In addition, a complex of Dendroctonus (western pine beetle (D. brevicomis), roundheaded pine beetle (D. adjunctus)) and Ips species were detected on dead and dying ponderosa pine throughout the Wallow Fire and in some of the PACs, in particular on dry sites. For example, 1 mile southwest of the Campbell Blue PAC a large pocket (>50 trees) of fading ponderosa pine was observed. Upon inspecting the dying trees most were found to be primarily attacked by engraver beetles, but some also had been colonized by mountain pine beetle and other Dendroctonus. Table 1. MCH treatments implemented in Mexican spotted owl (MSO) Protected Activity Centers (PACs) within and adjacent to the Wallow Fire. MSO PAC Name Ranger Total Comments District Acres 1011 Bull Canyon Alpine 29.3 MSO occupied. PP, DF, oak mix in upper canyon. Not evaluated. No beetle activity detected by ADS, but both DFB and FE activity mapped east and north of PAC Thomas Creek Alpine Several PP and SWWP fading trees were noted along ridge. DFB activity in adjacent area by Thomas Creek Weir. 10xx Campbell Blue Alpine 19 High level of FE activity on large, partially scorched WF. Fresh DFB attacks on 11 large DF with sparse crowns, heavy DM, and scorched boles Double Cienega Alpine Dense stand of larger DF, WF, spruce, and aspen with light to moderate burn. Moderate DFB activity on large DF with bole scorch and DM. Also FE on scorched WF Turkey Track Alpine Mix of DF, PP, WF with DF heavily infected with mistletoe. DF mortality appears to be caused by wood borers only. Also borers & FE on WF, WPB on PP Alpine West Alpine 8.5 No current DFB activity in PAC, but activity observed adjacent to PAC. Limited FE activity in PAC 6005 Greer Springerville Both DFB and MPB activity in and adjacent to PAC. Also high levels of true fir mortality. 6011a, b Badger Knoll Springerville MSO occupied. No DFB activity detected. Limited mortality of SWWP apparently caused by ips and wood borers. 6013a, b West Fr LCR Springerville Limited fresh DFB attacks observed. Increased level of spruce mortality caused by SB and spruce engraver; 1 SB pocket of > 25 blue spruce in 6013a near LCR. DF = Douglas-fir, WF = white fir, PP= ponderosa pine, SWWP = southwestern white pine, DFB = Douglas-fir beetle, FE = Fir Engraver, MPB = mountain pine beetle, WPB = western pine beetle, SB = spruce beetle, DM = dwarf mistletoe, LCR = Little Colorado River

7 6 MONITORING DOUGLAS-FIR BEETLE FLIGHT AND RELATIVE POPULATION SIZE Traps baited with bark beetle lures can be used to monitor the flight periodicity and relative population size of beetles. In order to monitor Douglas-fir beetle (and wood borers) flight and populations, three Lindgren funnel traps were installed at each of seven sites on May 22, Traps were baited with a commercially available Douglas-fir beetle lure, the Douglas-fir beetle lure plus a possible wood borer attractant, or only a different potential wood borer attractant. Traps were separated by approximately two chains and lures were replaced in early-july. Sites were selected to represent a cross-section of the Wallow Fire (Figure 4), and were in areas that had the potential for Douglas-fir beetle activity. The southernmost site (DFB-13-1) was located adjacent to Forest Service Road 54 near the Alpine and Clifton Ranger Districts border and the northernmost site was by Pat Knoll (DFB-13-7) on the Springerville Ranger District. Trap contents were collected every two three weeks by Forest personnel. At the end of the trap monitoring season (mid-september), a survey was conducted of Douglas-fir trees within a two chain radius of the traps to determine how many trees had been attacked by Douglas-fir beetles. Similar monitoring efforts and surveys around trap sites were conducted in 2012; however, only a single baited trap was located at each of four sites. In 2012, trap catches were relatively few compared to trapping efforts in other geographic regions where several hundred or more beetles have been caught per trap per day. Only the trap site near the junction of FR852 and FR249 had any apparent attacked trees ( spill-over ) adjacent to monitoring traps. This suggested that populations of Douglas-fir beetle were still low throughout much of the Wallow Fire area. In 2013, Douglas-fir beetle populations increased rather dramatically based on trap catches (Figure 5) and the number of infested trees near traps. Trap catches of Douglas-fir beetle during peak flight in 2013 (205/trap/day) were more than a level of magnitude higher than in 2012 (17/trap/day). Relatively large numbers of beetles had already begun flying by the first collection date of June 6, 2013 and continued through early-july. Small numbers of beetles were collected through the end of August. Although numerous beetles were caught at all seven sights, the most were caught near Burro Mountain (DFB-13-5) and the least at the Escudilla Mountain site (DFB-13-4). An average of approximately 15 current infested trees was detected near trap sites 1 through 5 in Time constraints prevented us from surveying around trap sites 6 and 7 in September, however, current infested trees were observed during earlier visits to these sites.

8 Beetles/trap/day 7 Figure 4. Location of trap sites to monitor Douglas-fir beetle populations in 2013 within the Wallow Fire perimeter on the Apache-Sitgreaves NF Collection Period Figure 5. Mean (+/- standard error) Douglas-fir beetles caught per trap per day in 2012 and 2013 within the Wallow Fire perimeter on the Apache-Sitgreaves NF.

9 8 MONITORING MOUNTAIN PINE BEETLE FLIGHT AND RELATIVE POPULATION SIZE Similar to monitoring efforts for Douglas-fir beetle, traps sites were established to monitor flight periodicity of mountain pine beetle and to collect information on relative population size. Four trap sites were stratified across the Wallow Fire (Figure 6) and ranged in elevation from approximately 8,400 ft. to 9,400 ft. The southernmost site was located near the Thomas Creek Weirs and the northernmost site was by Pat Knoll. Averaged across all monitoring sites, peak flight occurred between early to mid-august (Figure 7). However, at the lowest elevation site (8,390 ft.), beetles began flying slightly earlier and the peak flight occurred prior to the sites above 8,800 ft. The fewest beetles were trapped at the northern most site (#4 Pat Knoll), while approximately similar numbers were collected at the other three sites. Beetle flight was essentially completed by mid-september. Although trap catches were much lower than those of Douglas-fir beetle, the number of beetles caught indicates there is an active beetle population. Based on this information in combination with aerial and ground surveys, mountain pine beetle is expected to continue to impact southwestern white pine within the Wallow Fire perimeter during Although no data were collected on the size of trees being attacked by mountain pine beetle, anecdotal observations suggest larger diameter classes (> 14 inches DBH) of southwestern white pine are being impacted the most. Figure 6. Location of trap sites to monitor mountain pine beetle (MPB) populations in 2013 within the Wallow Fire perimeter on the Apache- Sitgreaves NF. Note that MPB - 2 is the same site as DFB-13-3 and MPB - 4 is the same site as DFB

10 Total beetles/trap/collection period Mean beetles/trap/day Mid July Early August Mid August Early September Collection Period Mid September Late September (8,390) 2 (9,422) 3 (8,808) 4 (9,360) Mid July Early August Mid August Early September Collection Period Mid September Late September Figure 7. Mean (+/- standard error) mountain pine beetles caught per trap per day (top) and by site (bottom) within the Wallow Fire perimeter on the Apache-Sitgreaves National Forest. Legend displays site number and elevation in feet.

11 10 POTENTIAL TREATMENTS TO REDUCE BARK BEETLE IMPACTS Tactics to manage bark beetles attacking conifer tree species in the western US include: 1. Silvicultural treatments that reduce stand density (thinning) and presumably host susceptibility (reviewed in Fettig et al. 2007, Fettig et al. 2014), 2. Sanitation practices that remove or treat infested trees (reviewed in Fettig et al. 2014), 3. Applications of insecticides to protect individual trees (Fettig et al. 2013a, b), and 4. Applications of semiochemicals (i.e., chemicals produced by one organism that elicit a behavioral response in another organism), including aggregation pheromones deployed in trap out, trap tree, or concentration approaches and inhibitors used to disrupt colonization of individual tree (reviewed in Progar et al. 2014). Often an integrated management approach is recommended that uses more than one of these approaches to improve the overall effectiveness of minimizing bark beetle impacts. A brief description of these approaches is provided below. Pheromone treatments to reduce bark beetle impacts Bark beetles use a complex system of pheromone (semiochemical) communication in host location, selection and colonization, and mating behaviors (Progar et al. 2014). In short, host tree colonization by many bark beetle species occurs in a behavioral sequence facilitated by aggregation pheromones and host volatiles such as monoterpenes. During the initial attack of trees aggregation pheromones are released to concentrate conspecifics to the target tree resulting in a mass attack on the tree; allowing beetles to overcome tree defenses. Increasing amounts of anti-aggregation pheromones are produced during the latter stages of tree colonization that reduces competition among beetles and their subsequent brood. Essentially this no vacancy message directs dispersing bark beetles to attack adjacent trees or fly elsewhere. It can also delay beetles from finding suitable host trees long enough to make them more susceptible to natural predation and other mortality factors (Ross et al., 2006). Although pheromones can be used in a variety of ways to affect the behavior and management of insects, three approaches most often used in the management of bark beetles include: 1. Monitoring of flight periods and populations using aggregation and host volatile-baited traps, 2. Suppression of bark beetle populations through the utilization of pheromone-baited traps, trees or logs, and 3. The use of anti-aggregation pheromones to protect vulnerable hosts from attack (Borden 1989). MCH for preventing Douglas-fir beetle attack. MCH (3-methylcyclohex-2-en-1-one) is an antiaggregation pheromone that Douglas-fir beetles release when they have populated a food source to capacity. MCH is a non-restricted use bio-pesticide that has been used successfully for over 20 years to protect localized areas and high value trees from being attacked by Douglas-fir beetle (Ross et al., 2006), with no reported adverse effects to humans or the environment (EPA fact sheet). MCH has also been used to prevent spruce beetle from attacking spruce trees when beetle populations are low or beginning to increase. Depending on the amount of trees or area to be protected, there are two application strategies for the placement of MCH pheromone bubble capsules (see Ross et al., 2006, for more details):

12 11 1. Areas with high concentrations of live large Douglas-fir trees received complete area protection by using a grid pattern to achieve an application rate of 30 caps per acre. A bubble capsule is stapled on the north side of the closest tree to maintain a 40 feet x 40 feet grid. 2. Areas with scattered individuals or groups of large Douglas-fir trees receive individual tree protection. In this case, multiple capsules are stapled on several sides of each large tree >15 dbh, as dictated by tree size. Two capsules are placed on opposite tree sides to protect trees. Trees received three caps evenly spaced around the tree bole. Trees over 24 dbh receive a total of four capsules each. Timing of pheromone release installation of devices is critical putting them out too early or too late reduces their effectiveness. These pheromone products are designed to only be effective for days in the open air, after which the pre-measured dose per bubble has dissipated. Approximately 1,814 acres were treated in 2012 to help preserve remaining MSO mixed-conifer habitat within and adjacent to the Wallow Fire perimeter. Treatment areas were focused on the most suitable MSO habitat including core nest areas within each PAC if applicable. Actual treatment polygons were delineated for each PAC during field application as areas of non-host trees, large openings, and high burn severity areas were omitted from treatment. As shown in Table 1, a total of about 57 acres were treated in Verbenone pouches for preventing mountain pine beetle attack. In recent years, research and operational treatments have focused on the use of anti-aggregation pheromone called verbenone to disrupt the responses of mountain pine beetle to attractants and to reduce levels of tree mortality (reviewed by Progar et al. 2014). Several methods for applying verbenone have been evaluated for protecting individual trees and forest stands from mortality attributed to mountain pine beetle. The most common method involves pouch release devices applied by hand. Pouches are typically stapled at maximum reach (> 6 feet in height) to individual trees prior to beetle flight in early to mid-summer. As with MCH bubble capsules, verbenone pouches are applied in either a gridded pattern of distribution to achieve uniform coverage when stand protection is the objective or on individual trees or small groups of clustered trees. Much of the research conducted on protection of individual trees with verbenone pouches has been on high elevation whitebark pine, for which they have been shown to be very effective. Recently, a SPLAT (Specialized Pheromone & Lure Application Technology; ISCA Technologies, Inc.) has been developed using a wax emulsion matrix that can be applied by hand (e.g., using a caulking gun) and provides a long-lasting, controlled-release formulation to dispense pheromones (reviewed by Progar et al. 2014). SPLAT has many desirable characteristics for use as a tree protection tool and this technology may be operationally available for verbenone during the 2014 season. Cost information and guidelines should be forthcoming in the near future.

13 12 Sanitation practices Sanitation involves the identification of currently infested trees and subsequent felling and removal or treatment (burning, chipping or debarking) to destroy bark beetle adults and brood beneath the bark. Sanitation is rarely fully effective as a management tool by itself to fully suppress bark beetle populations as infested trees are sometimes difficult to detect requiring regular annual or semi-annual surveys, and there are often seasonal, ecological and economic restrictions that prevent thorough sanitation efforts. However, sanitation practices can help to reduce local bark beetle pressure and decrease beetle impacts when combined with pheromone or other treatments. Recent reviews by Fettig and others (2014) and Progar and others (2014) provide strategies of how sanitation efforts can be combined with pheromone attractants and inhibitors for the management of bark beetles. Insecticide preventative treatments Numerous studies and operational usage of insecticide treatments over the past decade have demonstrate that preventative applications are a viable option for protecting individual trees from mortality due to bark beetle attack (recently reviewed by Fettig et al. 2013a). In an operational setting, only high-value, individual trees growing in unique environments (e.g., developed campgrounds, wildland-urban environments, critical habitat) are treated (Fettig et al. 2014). As outlined in by Fettig and others (2013a), bole sprays of carbaryl, bifenthrin, and permethrin are most commonly used and several formulations are available and highly effective if properly applied. At least one year of protection can be expected with a single application. In general, preventative applications of insecticides pose little threat to adjacent environments, and few negative impacts have been observed. Recent advances in methods and formulations for individual tree injection are promising, although more work is needed to validate efficacy for all bark beetle-host systems in the West (reviewed by Fettig et al. 2013a). The efficacy of phloem-mobile active ingredients injected with pressurized systems have been evaluated for engraver beetles, mountain pine beetle, southern pine beetle, spruce beetle, and western pine beetle. These systems push adequate volumes of product into the small vesicles of the sapwood. Applications take <15 minutes per tree under most circumstances. Following injection, the product is transported throughout the tree to the target tissue (i.e., the phloem where bark beetle feeding occurs). Injections can be applied at any time of year when the tree is actively translocating, but time is needed to allow for full distribution of the active ingredient within the tree prior to the tree being attacked by bark beetles. Under optimal conditions (e.g., adequate soil moisture, moderate temperatures and good overall tree health) this takes ~4 weeks, but may take much longer, particularly in high-elevation forests. For example, a recently published paper indicates that injections of emamectin benzoate applied in late summer or early fall will provide adequate levels of tree protection against mountain pine beetle the following summer (Fettig et al. 2013b). When emamectin benzoate is combined with propiconazole (a fungicide), tree protection is afforded the year that injections are implemented. Tree injections represent essentially closed systems

14 13 that eliminate drift, and reduce non-target effects and applicator exposure, but efficacy may be less than that observed for bole sprays in high-elevation forests. RECOMMENDATIONS Tree susceptibility to successful infestation by bark beetles remains high throughout the Wallow Fire area. Based on aerial & ground surveys and trap monitoring efforts, bark beetlecaused mortality of conifers was widespread throughout many locations in In our view developed recreation and administrative sites and MSO PACs will continue to be threatened by bark beetle impacts during Therefore, where feasible, an integrated management approach is recommended to minimize bark beetle-caused impacts to these valuable forest resources. The combination of treatments will likely be needed over the next few years while bark populations are high and suitable tree and stand conditions exist. The development of vegetation management plans for recreation and administrative sites would be useful by providing long-term direction for these high value areas. In addition to bark beetle susceptibility considerations, several diseases are present at these recreation sites, including root disease, dwarf mistletoes and stem decays, which should be accounted for. A biological evaluation was conducted by Fairweather and Wilson (1991) in the Big Lake recreation complex area and provides information on the extent and distribution of these diseases. MCH treatments are recommended again in 2014 for the three recreation sites (Big Lake, Gabaldon, Hannagan) due to the increase in Douglas-fir beetle activity in and around the recreation areas. In addition, verbenone can be used to minimize mountain pine beetle-caused mortality of southwestern white pine in select areas at Big Lake. Verbenone may also provide ancillary protection against Dendroctonus bark beetles attacking ponderosa pine in areas where they are near southwestern white pine being treated. In areas where the anti-aggregation pheromones are arranged in a grid pattern (i.e., Rainbow CG) a buffer of 40 or more feet outside the immediate camp sites is recommended. Sanitation cutting and removal of infested trees found in or adjacent to recreation sites is also encouraged. While this certainly will not affect the bark beetle population as a whole, it can aide in the reduction of local populations if completed in a timely fashion. Infested trees need to be felled and removed, or treated on site (debarked, chipped or burned), prior to beetle emergence to help prevent the increase of beetle populations. In the case of Douglas-fir beetle in Douglas-fir and bark beetles that have colonized ponderosa pine this work needs to be completed before early May. For mountain pine beetle on southwestern white pine work should be completed by the end of June. Any funds requested for sanitation work should include costs for both currently infested trees and any new trees that are attacked during the 2014 beetle flight period. A prioritized number of MSO PAC sites should also be considered for treatment using MCH and verbenone. Based on observations during our surveys, a combination of grid distribution and individual tree treatment approaches would be appropriate for many of the core MSO PAC habitat areas due to the variable spatial host tree distribution. To increase efficiency of

15 14 installing verbenone during the appropriate time window (mid-june through mid-july), crews stapling MCH bubble capsules in April-May can record which PACs have enough southwestern white pine to justify a return trip for verbenone treatments about a month later. Each MCH field crew could be tasked with flagging spots that have clumps of large, live southwestern white pine trees and recording a GPS waypoint with number of white pine trees noted. It is important to note that while protecting large diameter Douglas-fir and southwestern white pine trees is the focus of MCH and verbenone treatments, respectively, some level of tree mortality can be expected within PAC areas that have been treated with anti-aggregation pheromones. MCH and verbenone target specific bark beetle species and will not affect Ips, Scolytus or wood borers. These species have been active within the Wallow Fire area and are contributing to mortality of a variety of conifers. For example, considerable white fir mortality caused by fir engraver was observed in some PACs. There are no anti-aggregation pheromones available for the management of these species. Monitoring of bark beetle activity is important for both MSO PACs and in developed recreation and administrative sites. Monitoring activities can include funnel traps baited with bark beetle lures, ground surveys, and analysis of susceptible areas. Continued monitoring of both Douglas-fir beetle and mountain pine beetle is warranted during Our staff can assist in the design and implementation of a bark beetle monitoring program for 2014 and beyond. Keeping monitoring traps at least 100 feet from nearest host tree, if possible, will help to minimize the potential for spill-over. Traps can also be located in stands of non-host trees, areas of prior Douglas-fir mortality, or among small diameter Douglas-fir that are unsuitable as Douglas-fir beetle host trees. If bark beetle populations increase further next year and impacts continue to escalate, the use of preventative insecticides may be warranted. The Arizona Zone Forest Health staff can assist in such a determination and provide guidance in the use of these preventative treatments. REFERENCES CITED Borden, J.T Semiochemicals and bark beetle populations: Exploitation of natural phenomena by pest management strategists. Holarctic Ecology 12: EPA. 3-Methyl-2-cyclohexene-1-one (MCH) (219700) Fact Sheet pdf Fairweather, M.L. and J. Wilson Biological evaluation of pest conditions in the Big Lake Management Complex, Apache-Sitgreaves National Forests, Arizona. USDA Forest Service, Southwestern Region publication R p. Fettig, C.J., K.D. Klepzig, R.F. Billings, A.S. Munson, T.E. Nebeker, J.F. Negrón, and J.T. Nowak The effectiveness of vegetation management practices for prevention and control of

16 15 bark beetle infestations in coniferous forests of the western and southern United States. Forest Ecology and Management 238: Fettig, C.J., D.M. Grosman, and A.S. Munson. 2013a. Advances in insecticide tools and tactics for protecting conifers from bark beetle attack in the western United States. Pp In: S. Trdan (Ed.) Insecticides - Development of Safer and More Effective Technologies. InTech, Rijeka, Croatia. Fettig, C.J., A.S. Munson, D.M. Grosman, and P.B Bush. 2013b. Evaluations of emamectin benzoate and propiconazole for protecting individual Pinus contorta from mortality attributed to colonization by Dendroctonus ponderosae and associated fungi. Pest Management Science. 8 p. Fettig, C.J., K.E. Gibson, A.S. Munson, and J.F. Negrón Cultural practices for prevention and mitigation of mountain pine beetle infestations. Forest Science., in press. Furniss, R.L. and V.M. Carolin Western Forest Insects. USDA Forest Service Misc. Publication p. Progar, R.A., N. Gillette, C.J. Fettig, and K. Hrinkevich Applied chemical ecology of the mountain pine beetle. Forest Science, in press. Ross, D.W., K.E. Gibson, and G.E. Daterman Using MCH to protect trees and stands from Douglas-fir beetle infestation. USDA Forest Service, FHTET (revised March 2006). 11 p.