Mortality Associated with a Bark Beetle Outbreak in Dwarf Mistletoe-Infested Ponderosa Pine Stands in Arizona

Abstract Ponderosa pine (Pinus ponderosa Douglas ex C. Lawson var. scopulorum Engelm.) mortality was evaluated from a 2002 bark beetle outbreak in areas infested with southwestern dwarf mistletoe (Arceuthobium vaginatum [Willd.] Presl subsp. cryptopodum [Engelm.] Hawksw. & Wiens) in a total of nine study sites in northern Arizona. Ponderosa pine mortality attributable to bark beetles (Ips and Dendroctonus spp., Scolytidae) was systematically sampled, and stand attributes, such as basal area, tree density, dwarf mistletoe severity, and site indices were recorded. Ponderosa pine mortality was predominately attributed to Ips spp. Although the prolonged drought likely was the inciting factor responsible for the Ips spp. outbreak, results suggested a strong relationship between ponderosa pine mortality and the interaction between crown class and dwarf mistletoe rating class. Ponderosa pines severely infected with dwarf mistletoe and in the intermediate crown class are at the greatest risk of Ips spp. attack during outbreak years in northern Arizona.

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Thinning ponderosa pine (Pinus ponderosa) stands reduces mortality while maintaining stand productivity

Canadian Journal of Forest Research ◽

10.1139/cjfr-2012-0411 ◽

2013 ◽

Vol 43 (4) ◽

pp. 311-320 ◽

Cited By ~ 21

Author(s):

Jianwei Zhang ◽

Martin W. Ritchie ◽

Douglas A. Maguire ◽

William W. Oliver

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Bark Beetles ◽

Basal Area ◽

Stand Density ◽

Growth Efficiency ◽

Stand Age ◽

Annual Increment ◽

Stand Productivity ◽

Residual Variation

We analyzed 45 years of data collected from three ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) levels-of-growing-stock installations in Oregon (OR) and northern California (CA), USA, to determine the effect of stand density regimes on stand productivity and mortality. We found that periodic annual increment (PAI) of diameter, basal area (BA), volume, and aboveground dry mass were significantly related to stand density index (SDI) and stand age at start of the period; the quadratic trends varied among sites. Precipitation departure from the normal for each period explained a significant amount of residual variation in all PAI variables except diameter. BA production did not change significantly as SDI exceeded 270 trees·ha−1 at the OR sites and 320 trees·ha−1 at the CA site. Stand productivity was the highest at Elliot Ranch (CA) and the least at Blue Mountains (OR). A similar trend held in growth efficiency under lower stand densities (SDI < 600). Most of the mortality was caused by Dendroctonus bark beetles in stands that exceeded SDI of 500 trees·ha−1. Limiting SDI was about 900 trees·ha−1, although plots at Elliot Ranch reached much higher than that. The results demonstrate that silvicultural control of stand density can be a powerful tool for reducing bark beetle caused mortality without sacrificing stand productivity.

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Western Dwarf Mistletoe Parasitizing Colorado Blue Spruce and Norway Spruce in California

Plant Disease ◽

10.1094/pdis.1998.82.3.351e ◽

1998 ◽

Vol 82 (3) ◽

pp. 351-351 ◽

Cited By ~ 1

Author(s):

R. L. Mathiasen ◽

J. R. Allison ◽

B. W. Geils

Keyword(s):

Norway Spruce ◽

Pinus Ponderosa ◽

Ponderosa Pine ◽

Natural Infection ◽

Dwarf Mistletoe ◽

First Report ◽

Blue Spruce ◽

Northern Arizona ◽

Jeffrey Pine ◽

Shoot Production

Western dwarf mistletoe (Arceuthobium campylopodum Engelm.), a common parasite of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.), was found parasitizing planted Colorado blue spruce (Picea pungens Engelm.) and Norway spruce (Picea abies (L.) H. Karsten) in Upper Cuddy Valley, CA (Kern County, T. 9 N., R. 21 W., Sec. 25). One tree greater than 6 m in height of each spruce species was infected and both trees were within 12 m of a Jeffrey pine severely infected with western dwarf mistletoe. Five to 10 branches were infected on each tree and a few of these had abundant mistletoe shoot production, which allowed identification of the parasite. This is the first report of western dwarf mistletoe on Colorado blue spruce. Although this is the first report of natural infection of Norway spruce in California, this mistletoe/host combination has been reported by Weir from artificial inoculation (2) and collected by Russell in central Washington (1). We recommend that these spruce species not be planted within 15 m of pines infected with western dwarf mistletoe. Specimens of western dwarf mistletoe on Colorado blue spruce and Norway spruce were collected and deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff. References: (1) F. G. Hawksworth and D. Wiens. 1996. Dwarf Mistletoes: Biology, Pathology, and Systematics. USDA Agric. Handb. 709. (2) J. R. Weir. Bot. Gaz. 56:1, 1918.

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Effectiveness of Two Systemic Insecticides for Protecting Western Conifers from Mortality Due to Bark Beetle Attack

Western Journal of Applied Forestry ◽

10.1093/wjaf/25.4.181 ◽

2010 ◽

Vol 25 (4) ◽

pp. 181-185 ◽

Cited By ~ 11

Author(s):

Donald M. Grosman ◽

Christopher J. Fettig ◽

Carl L. Jorgensen ◽

A. Steven Munson

Keyword(s):

Bark Beetle ◽

Pinus Ponderosa ◽

Ponderosa Pine ◽

Bark Beetles ◽

Tree Mortality ◽

Dendroctonus Brevicomis ◽

Emamectin Benzoate ◽

The Third ◽

Systemic Insecticides ◽

Pine Beetle

Abstract Bark beetles (Coleoptera: Curculionidae, Scolytinae) are important tree mortality agents in western coniferous forests. Protection of individual trees from bark beetle attack has historically involved applications of liquid formulations of contact insecticides to the tree bole using hydraulic sprayers. More recently, researchers looking for more portable and environmentally safe alternatives have examined the effectiveness of injecting small quantities of systemic insecticides directly into trees. In this study, we evaluated trunk injections of experimental formulations of emamectin benzoate and fipronil for preventing tree mortality due to attack by western pine beetle (Dendroctonus brevicomis LeConte) on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) in California, mountain pine beetle (Dendroctonus ponderosae Hopkins) on lodgepole pine (Pinus contorta Dougl. ex Loud.) in Idaho, and spruce beetle (D. rufipennis [Kirby]) on Engelmann spruce (Picea engelmannii Parry ex Engelm.) in Utah. Fipronil appeared ineffective for protecting P. ponderosa from mortality due to D. brevicomis over the 3 years in California because of insufficient mortality of untreated, baited control trees the first 2 years and high mortality of the fipronil-treated trees in the third year. Emamectin benzoate was effective in providing protection of P. ponderosa from D. brevicomis during the third year following a single application. To our knowledge, this is the first demonstration of the successful application of a systemic insecticide for protecting individual conifers from mortality due to bark beetle attack in the western United States. Estimates of efficacy could not be made during both field seasons in P. contorta because of insufficient mortality in control trees. Both emamectin benzoate and fipronil were ineffective for protecting P. engelmannii from D. rufipennis. Lower ambient and soil temperatures and soil moisture may have limited chemical movement and thus efficacy at the Idaho and Utah sites.

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Fire-injured ponderosa pine provide a pulsed resource for bark beetles

Canadian Journal of Forest Research ◽

10.1139/x2012-147 ◽

2012 ◽

Vol 42 (12) ◽

pp. 2022-2036 ◽

Cited By ~ 35

Author(s):

Ryan S. Davis ◽

Sharon Hood ◽

Barbara J. Bentz

Keyword(s):

Bark Beetle ◽

Pinus Ponderosa ◽

Ponderosa Pine ◽

Bark Beetles ◽

Mountain Pine Beetle ◽

Rocky Mountain ◽

Dendroctonus Brevicomis ◽

Brood Production ◽

Pine Beetle ◽

Tree Injury

Bark beetles can cause substantial mortality of trees that would otherwise survive fire injuries. Resin response of fire-injured northern Rocky Mountain ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson) and specific injuries that contribute to increased bark beetle attack susceptibility and brood production are unknown. We monitored ponderosa pine mortality and resin flow and bark beetle colonization and reproduction following a prescribed fire in Idaho and a wildfire in Montana. The level of fire-caused tree injury differed between the two sites, and the level of tree injury most susceptible to bark beetle attack and colonization also differed. Strip-attacked trees alive 3 years post-fire had lower levels of bole and crown injury than trees mass attacked and killed by bark beetles, suggesting that fire-injured trees were less well defended. Brood production of western pine beetle ( Dendroctonus brevicomis LeConte) did not differ between fire-injured and uninjured trees, although mountain pine beetle ( Dendroctonus ponderosae Hopkins) brood production was low in both tree types, potentially due to competition with faster developing bark beetle species that also colonized trees. Despite a large number of live trees remaining at both sites, bark beetle response to fire-injured trees pulsed and receded within 2 years post-fire, potentially due to a limited number of trees that could be easily colonized.

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Assemblage of Hymenoptera arriving at logs colonized by Ips pini (Coleoptera: Curculionidae: Scolytinae) and its microbial symbionts in western Montana

The Canadian Entomologist ◽

10.4039/n09-004 ◽

2009 ◽

Vol 141 (2) ◽

pp. 172-199 ◽

Cited By ~ 6

Author(s):

Celia K. Boone ◽

Diana L. Six ◽

Steven J. Krauth ◽

Kenneth F. Raffa

Keyword(s):

Bark Beetle ◽

Pinus Ponderosa ◽

Ponderosa Pine ◽

Bark Beetles ◽

Host Plants ◽

Ips Pini ◽

Feeding Guilds ◽

Forestry Practices ◽

Nontarget Effects ◽

Microbial Symbionts

AbstractColonization of a tree by bark beetles and their symbionts creates a new habitat for a diverse assemblage of arthropods, including competing herbivores, xylophages, fungivores, saprophages, predators, and parasitoids. Understanding these assemblages is important for evaluating nontarget effects of various management tactics and for subsequently evaluating how changes in climate, the presence of invasive species, and altered forestry practices and land-use tenure may affect biodiversity. We characterized the assemblage of hymenopterans attracted to logs of ponderosa pine (Pinus ponderosa C. Lawson (Pinaceae)) colonized by the bark beetle Ips pini (Say) and its microbial symbionts. In one experiment, the composition and relative abundances of species arriving at hosts colonized by I. pini, and possible sources of attraction, were determined. Treatments consisted of a log containing I. pini with its natural complement of microorganisms, a log alone, and a blank control. A second experiment was carried out to determine whether or not Hymenoptera were attracted to microbial symbionts of I. pini. Treatments consisted of a blank control, a log alone, a log containing I. pini with its natural complement of microorganisms, either Ophiostoma ips, Burkholderia sp., or Pichia scolyti, and a log inoculated with a combination of these three microorganisms. Over 2 years, 5163 Hymenoptera were captured, of which over 98% were parasitoids. Braconidae, Platygastridae, Encyrtidae, Pteromalidae, and Ichneumonidae were the most abundant. Seven known species of bark beetle parasitoids (all Pteromalidae) were captured. However, parasitoids of Diptera, Lepidoptera, Hymenoptera, and non-wood-boring Coleoptera were also common. Nineteen species showed preferential attraction to host plants infested with I. pini and its complement of microorganisms, host plants inoculated with I. pini microbial symbionts, or host plants alone. Interestingly, many of these species were parasitoids of phytophagous, fungivorous, and saprophytic insects rather than of bark beetles themselves. These results suggest that a diverse assemblage of natural enemies that attack various feeding guilds within a common habitat exploit common olfactory cues.

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First Report of Arceuthobium vaginatum subsp. cryptopodum on Pinus mugo

Plant Disease ◽

10.1094/pdis.2003.87.11.1395c ◽

2003 ◽

Vol 87 (11) ◽

pp. 1395-1395

Author(s):

R. Mathiasen ◽

M. Haefeli ◽

D. Leatherman

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Pinus Mugo ◽

Black Forest ◽

Dwarf Mistletoe ◽

First Report ◽

Northern Mexico ◽

Northern Arizona ◽

Positive Identification ◽

Northern Arizona University

Southwestern dwarf mistletoe (Arceuthobium vaginatum (Willd.) Presl subsp. cryptopodum (Engelm.) Hawksw. & Wiens, family Viscaceae) is a serious and common pathogen of ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) in Colorado, Utah, Arizona, New Mexico, and northern Mexico (1). In July 2002, this dwarf mistletoe was observed parasitizing a 1.4-m tall mugo pine (P. mugo Turra) in the Black Forest north of Colorado Springs, CO (39°02.118′N, 104°36.028′W, elevation 2,250 m). The infected mugo pine was planted as an ornamental approximately 6 m from a ponderosa pine infected with A vaginatum subsp. cryptopodum. Dwarf mistletoe shoots were produced on the only infected branch observed but this was sufficient for a positive identification of the dwarf mistletoe. Although J. Weir successfully inoculated mugo pine with western dwarf mistletoe (A. campylopodum Engelm.) and lodgepole pine dwarf mistletoe (A. americanum Nutt. ex Engelm.) (2), to our knowledge, this is the first report of a dwarf mistletoe occurring naturally on P. mugo, as well as the first report of A vaginatum subsp. cryptopodum on P. mugo (1). Specimens of A vaginatum subsp. cryptopodum from P. mugo have been deposited in the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 73761). References: (1) F. Hawksworth and D. Wiens. Dwarf mistletoes: biology, pathology, and systematics. USDA Agric. Handb. 709, 1996. (2) J. Weir. Bot. Gaz. 56:1, 1918.

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Twenty-Five-Year Growth and Mortality of Planted Ponderosa Pine Repeatedly Thinned to Different Stand Densities in Northern California

Western Journal of Applied Forestry ◽

10.1093/wjaf/12.4.122 ◽

1997 ◽

Vol 12 (4) ◽

pp. 122-130 ◽

Cited By ~ 8

Author(s):

William W. Oliver

Keyword(s):

Sierra Nevada ◽

Pinus Ponderosa ◽

Ponderosa Pine ◽

Bark Beetles ◽

Basal Area ◽

Stand Density ◽

Northern California ◽

Winter Storms ◽

Randomized Design ◽

Lower Site

Abstract A 20 yr old ponderosa pine (Pinus ponderosa var. ponderosa) plantation on a productive site on the west slope of the Sierra Nevada in northern California was thinned four times over a 25 yr period. Stand densities tested were Stand Density Indexes (SDI) of 73, 128, 183, 238, and 293 (equivalent to 40,70,100,130, and 160 ft2/ac of basal area), replicated three times in a randomized design. Growth was analyzed for each of five 5 yr periods. Periodic annual increments (PAI) of diameter, net basal area, and net total volume differed significantly among periods and, in the earlier periods, among stocking levels. Mortality from winter storms and bark beetles was largely confined to the higher stand densities and in periods 3 and 4 caused PAIs of net basal area and net total volume to decline below that of lower densities. The sensitivity of mortality to stand density suggests a thinning target of SDI 183 (about 100 ft²/ac of basal area) for similar stands—no higher than that recommended for eastside stands of much lower site productivity. This sensitivity coupled with rapid growth suggests that multiple thinnings will be necessary in similar stands to maintain healthy, vigorous trees. West. J. Appl. For. 12(4):122-130.

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Southwestern Dwarf Mistletoe, Arceuthobium vaginatum subsp. cryptopodum, Found Parasitizing Picea pungens in Colorado

Plant Disease ◽

10.1094/pd-89-0106b ◽

2005 ◽

Vol 89 (1) ◽

pp. 106-106

Author(s):

R. Mathiasen ◽

N. Marcus

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Morphological Description ◽

Dwarf Mistletoe ◽

First Report ◽

Blue Spruce ◽

Northern Arizona ◽

Picea Pungens ◽

Voucher Specimens ◽

Pinus Spp

Southwestern dwarf mistletoe (Arceuthobium vaginatum (Willd.) Presl subsp. cryptopodum (Engelm.) Hawksw. & Wiens, Viscaceae) severely parasitizes several species of pines (Pinus spp., family Pinaceae) in Colorado, Utah, Arizona, New Mexico, and northern Mexico, but it has not been reported to parasitize any species of spruce (Picea, family Pinaceae) (1). However, in June 2004, this dwarf mistletoe was observed parasitizing blue spruce (Picea pungens Engelm.) in the Black Forest north of Colorado Springs, CO (39°02.118′N, 104°36.028′W, elevation 2,250 m). The infected blue spruce was planted as an ornamental approximately 4 m from a 16-m-high ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) severely infected with southwestern dwarf mistletoe. Mature dwarf mistletoe shoots were produced on five infected branches of the blue spruce. These shoots were compared with a morphological description of southwestern dwarf mistletoe (1) and this was sufficient for a positive identification of the dwarf mistletoe. The other dwarf mistletoes reported to infect blue spruce are Arceuthobium microcarpum (Engelm.) Hawksw. & Wiens, A. americanum Nutt. ex Engelm., and A. douglasii Engelm.; these are all morphologically distinct from southwestern dwarf mistletoe (1). Three of the infected branches formed small (less than 0.3 m in diameter), nonsystemic witches' brooms. All of the infections on the 6-m-high blue spruce were higher than 1 m on the tree. Thus, it is likely that the spruce was infected after it was transplanted. Three other blue spruces were also located within 4 m of the infected ponderosa pine, but these trees were not infected. To our knowledge, this is the first report of southwestern dwarf mistletoe parasitizing blue spruce and the first report of this dwarf mistletoe on Picea spp. Voucher specimens have been deposited in the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 73959). References: (1) F. Hawksworth and D. Wiens. Dwarf mistletoes: Biology, pathology, and systematics. USDA For. Serv. Agric. Handb. 709, 1996.

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Drought-accelerated Parasitism of Conifers in the Mountain Ranges of Northern California

Environmental Conservation ◽

10.1017/s0376892900027661 ◽

1981 ◽

Vol 8 (3) ◽

pp. 217-226 ◽

Cited By ~ 9

Author(s):

James M. Page

Keyword(s):

Bark Beetle ◽

Pinus Ponderosa ◽

Bark Beetles ◽

Dendroctonus Brevicomis ◽

Northern California ◽

Dwarf Mistletoe ◽

Natural Fire ◽

Silvicultural Practices ◽

Natural Equilibrium ◽

Inducing Factors

Drought conditions in Northern California during 1975–77 caused widespread mortality in conifer forests mainly from attacks by disease organisms—including dwarf mistletoes and Fungi—and from epidemic outbreaks of various bark beetles. A federal survey has estimated the volume losses sustained through the affected four years (1975–79) as 9.6 thousand million board feet (45.3 million cubic metres) on 6.3 million acres (2.55 million ha) of national forest. As the dominant host species in afflicted forests is Pinus ponderosa, the most destructive agents have been the parasites of this species—primarily the Western Pine Beetle (Dendroctonus brevicomis) and the Western Dwarf Mistletoe (Arceuthobium campylopodum). However, interrelationships between many stress-inducing factors may be of more significance than the direct attack by any single parasitic species on a host.Three approaches to the reduction of conifer losses have been studied. The first involves the use of silvicultural practices based on the elimination of susceptible, or high-risk, trees. This is most applicable in countering bark beetles which have the mobility and selectivity to reach potential hosts over large areas.The second approach is direct control, or the physical removal or destruction of parasites. The steady spread of dwarf mistletoe, formerly contained by natural fire, can only be slowed through pruning, logging, or burning. Bark beetles can be directly controlled if the work is done before new broods hatch and mature. Toxic pesticides such as Lindane have proven ineffective—mainly for economic reasons, but also due to serious reservations among some foresters about detrimental effects on the forest ecosystem. Sex attractants have been used to draw bark beetles into trees of which the removal is planned.The third approach, applicable to bark beetles, is biological control, or reliance on organisms—such as lizards, woodpeckers, predaceous beetles and their larvae, parasitic hymenopterans, and various Fungi, which in some cases the forester has options to encourage or discourage. At the very least these controls suppress bark beetle populations when normal precipitation patterns return.Unfortunately, the ideal of a natural equilibrium being reached solely with the use of biological controls is unrealistic. The most fundamental stress on the commercial forests of California is human use, in spite of occasional drought-accelerated epidemic losses to parasites. Salvage must continue to be aggressively pushed upon a reluctant industry, but, above all, more flexible and immediate responses to the first signs of increasing bark-beetle activity, coupled with indirect, pre-epidemic silvicultural practices based on the broader lessons of forest parasitology, must be developed.

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Density-dependent population dynamics of mountain pine beetle in thinned and unthinned stands

Canadian Journal of Forest Research ◽

10.1139/x11-007 ◽

2011 ◽

Vol 41 (5) ◽

pp. 1031-1046 ◽

Cited By ~ 12

Author(s):

Chris J.K. MacQuarrie ◽

Barry J. Cooke

Keyword(s):

Population Dynamics ◽

Pinus Ponderosa ◽

Ponderosa Pine ◽

Bark Beetles ◽

Mountain Pine Beetle ◽

Basal Area ◽

Mortality Data ◽

Density Dependent ◽

Mountain Pine ◽

Pine Beetle

Thinning, the selective removal of some trees from a forest, is one way forest managers can reduce the probability that a forest will be susceptible to attack by bark beetles. Although this method has been shown to be effective, it is not clear whether the effect arises when pre-outbreak populations are small or during the epidemic phase when outbreaks are growing. We adopted a population dynamics approach to determine if the effect of limit or basal area thinning could be observed in the form of differential beetle recruitment using lodgepole pine ( Pinus contorta Dougl. ex Loud.) and ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) mortality data from previously published studies as a proxy measure of mountain pine beetle ( Dendroctonus ponderosae Hopkins) population size. We found that mountain pine beetle populations exhibit density-dependent population dynamics that are influenced by the silvicultural history of their host’s stand. Thinning did not change the epidemic equilibrium but instead caused a shift in dynamics from linear to nonlinear. In a validation test, the models developed for thinned and unthinned stands predicted reproductive rates in independent locations. These data also suggest the epidemic dynamics of mountain pine beetle may be sensitive to perturbations and to systematic trends associated with climate variability and climate change.

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