Identification of Insect Inclusions in X-rays of Ponderosa Pine Bark Infested by Western Pine Beetle, Dendroctonus brevicomis LeConte

1964 ◽  
Vol 96 (6) ◽  
pp. 883-888 ◽  
Author(s):  
A. A. Berryman

AbstractA guide to interpretation of X-rays of bark samples infested with the western pine beetle and its principal predators and parasites is presented. Illustrations of the radiographic images are given to enable analysts to gain experience more rapidly.

1972 ◽  
Vol 50 (9) ◽  
pp. 1943-1945 ◽  
Author(s):  
H. S. Whitney ◽  
F. W. Cobb Jr.

Three fungi—Ceratocystis nigrocarpa Davidson, an unidentified hyphomycete, and an unidentified basidiomycete—were isolated from extensive non-stained areas of sapwood of ponderosa pine infested with western pine beetle, Dendroctonus brevicomis Lec., in California. The two unidentified fungi were also present in the thoracic mycangium of the female beetle while C. nigrocarpa was found only externally on the beetle. The mycangium and its contents are illustrated. Ceratocystis minor (Hedgc.) Hunt, which was also found externally on the beetle but not in the mycangium, was isolated only from scattered patches of blue-stained sapwood. It is suggested that non-staining fungi play a role in causing the death of ponderosa pine trees attacked by D. brevicomis.


1971 ◽  
Vol 103 (9) ◽  
pp. 1291-1313 ◽  
Author(s):  
Cornell O. Dudley

AbstractThe distributions of attack, gallery length, eggs, and first instar larvae of an endemic population of the western pine beetle in ponderosa pine are described.Mean gallery length (GL) and larval (L) densities of mature populations are significantly correlated with attack (A) density. The associations are adequately described by the simple linear regressionsThe ratios E/GL and L/GL are stable over a wide range of gallery length densities and consequently egg-gallery length and larval-gallery length correlations are highly significant. The regression equations areAll four equations predict values within 10% of observed values.An 88 cm2 sampling unit is satisfactory for sampling either egg or first instar larval populations. Taking four paired sampling units, evenly spaced along the infested bole, from each of four trees per generation, provided a sampling precision of 15%. Increasing the number of paired units to 10 and the number of trees sampled per generation to 9 improved the precision to 10%. If the trees are sampled before oviposition is complete, the number of sampled trees per generation should be increased by 1 for each level of precision.


1984 ◽  
Vol 62 (3) ◽  
pp. 551-555 ◽  
Author(s):  
T. D. Paine

The hypersensitive response obtained by inoculating the two mycangial fungi of the western pine beetle, Dendroctonus brevicomis LeC, and the blue-stain fungus, Ceratocystis minor Hedge, into ponderosa pine was measured during three different seasons in the same 12-month period. The lesions were produced faster and were significantly longer in the fall than in the summer. Similarly, lesions were longer and were produced faster when inoculations made in the summer were compared with spring inoculations. However, the response to a nonpathogenic fungus, a Penicillium sp., was not different from the response to mycangial fungi, suggesting that lesion production is a generalized response to infection that isolates fungus-colonized tissue from the rest of the tree. Ethanol extracts of hypersensitive-response lesions produced during the spring did not reduce growth of the mycangial fungi or C. minor when bioassayed at concentrations similar to those found in host tissue. This is different from other bark beetle–host tree systems that have been investigated.


1986 ◽  
Vol 64 (7) ◽  
pp. 1507-1509 ◽  
Author(s):  
Thomas M. Pettey ◽  
Charles Gardner Shaw

Isolations of Hymenomycetes on a preferential medium were attempted from preflight pine engraver beetles, Ips pini, and the following in-flight bark beetles: pine engraver beetle, I. pini; western pine beetle, Dendroctonus brevicomis; mountain pine beetle, Dendroctonus ponderosae; and red turpentine beetle, Dendroctonus valens. Thirty pine engraver beetles removed from ponderosa pine slash (preflight) yielded no hymenomycete. However, Hymenomycetes were isolated from 50 of 114 beetles (all species) trapped in flight; Fomitopsis pinicola from 44, and other unidentified suspected Hymenomycetes, from 6. Cryptoporus volvatus was not isolated from any of the in-flight beetles. Since most of these isolates were without clamps (monokaryotic), the beetles may acquire basidiospores after emergence from beetle galleries in coniferous trees as hypothesized previously for the Douglas-fir beetle, Dendroctonus pseudotsugae. The isolation of F. pinicola from all species of in-flight bark beetles indicates that these beetles may be important in the dissemination of this hymenomycete.


1969 ◽  
Vol 101 (2) ◽  
pp. 113-117 ◽  
Author(s):  
J. P. Vité ◽  
G. B. Pitman

AbstractDendroctonus brevicomis Lec. responded in flight to combinations of insect- and host-produced volatiles. Emergent female beetles crushed at −70 °C, as well as synthetic exo-7-ethyl-5-methyl-6, 8-dioxabicyclo [3.2.1] octane (“brevicomin”) attracted both sexes of the western pine beetle when offered with oleoresin freshly tapped from the host, Pinus ponderosa Laws. Offered separately, these materials were inactive. Crushed emergent Dendroctonus ponderosae Hopk. males per se, however, attracted flying D. brevicomis in appreciable numbers. Dominance of either host odor or insect pheromone appeared to govern the sex ratio of the responding insects.


Insects ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 377
Author(s):  
Osiris Valerio-Mendoza ◽  
Jazmín García-Román ◽  
Moises Becerril ◽  
Francisco Armendáriz-Toledano ◽  
Gerardo Cuéllar-Rodríguez ◽  
...  

The western pine beetle (WPB), Dendroctonus brevicomis LeConte, is a major mortality agent of pines in North America. A total of 706 adults of WPB from 81 geographical sites were analyzed with traditional and geometric morphometric methods to evaluate the variation of discrete and quantitative morphological characters with particular attention to the antenna, spermatheca, and seminal rod. Principal coordinates and canonical variate analyses supported three geographical groups in WPB: (1) West, from British Columbia to southern California along the Pacific coast, Idaho, and Montana; (2) East-SMOC, including Nevada, Utah, Colorado, Arizona, New Mexico, Texas, Chihuahua, and Durango; and (3) SMOR, including Coahuila, Nuevo Leon, and Tamaulipas. The pubescence length on the elytral declivity was a robust character for separating West specimens from the other groups. Additionally, the genitalia shape both female and male in dorsal view was a reliable character for discriminating among groups. Based on these results, which agree with genetic and chemical ecology evidence, we herein reinstate Dendroctonus barberi Hopkins (East-SMOC group) and remove it from synonymy with D. brevicomis (West group). Differences in the spermatheca and seminal rod shape of SMOR specimens suggest that these populations might be a different species from D. barberi and D. brevicomis.


2008 ◽  
Vol 23 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Christopher J. Fettig ◽  
Christopher P. Dabney ◽  
Stephen R. McKelvey ◽  
Dezene P.W. Huber

Abstract Nonhost angiosperm volatiles (NAV) and verbenone were tested for their ability to protect individual ponderosa pines, Pinus ponderosa Dougl. ex. Laws., from attack by western pine beetle (WPB), Dendroctonus brevicomis LeConte, and red turpentine beetle (RTB), Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae). A combination of (−)-verbenone and eight NAVs [benzyl alcohol, benzaldehyde, guaiacol, nonanal, salicylaldehyde, (E)-2-hexenal, (E)-2-hexen-1-ol, and (Z)-2-hexen-1-ol] (NAVV) significantly reduced the density of WPB attacks and WPB successful attacks on attractant-baited trees. A significantly higher percentage of pitchouts (unsuccessful WPB attacks) occurred on NAVV-treated trees during two of three sample dates. In addition, significantly fewer RTB attacks were observed on NAVV-treated trees during all sampling dates. The application of NAVV to individual ponderosa pines significantly reduced tree mortality, with only 4 of 30 attractant-baited trees dying from bark beetle attack while 50% mortality (15/30) was observed in the untreated, baited control. To our knowledge, this is the first report establishing the effectiveness of NAVs and verbenone for protecting individual ponderosa pines from WPB attack.


1958 ◽  
Vol 90 (10) ◽  
pp. 582-584 ◽  
Author(s):  
R. L. Lyon

The sex of the western pine beetle (Dendroctonus brevicomis Lec.) and the mountain pine beetle (Dendroctonus monticolae Hopk.) can be ascertained easily and with 100 percent accuracy by means of a secondary sex character on the seventh abdominal tergite of the male. This character can probably be used with equal accuracy to identify sex in all species of the genus Dendroctonus.The need to distinguish between the sexes of adult bark beetles often arises in studies of biology, behavior, or response. The sexing procedure is laborious when large numbers of beetles are involved and external markings of sex are not known. It is then necessary to dissect each beetle to check the genitalia. Dissection is impossible when iniury to the insect must be avoided.


2008 ◽  
Vol 38 (5) ◽  
pp. 924-935 ◽  
Author(s):  
Christopher J. Fettig ◽  
Robert R. Borys ◽  
Stephen R. McKelvey ◽  
Christopher P. Dabney

Mechanical thinning and the application of prescribed fire are commonly used tools in the restoration of fire-adapted forest ecosystems. However, few studies have explored their effects on subsequent amounts of bark beetle caused tree mortality in interior ponderosa pine, Pinus ponderosa Dougl. ex P. & C. Laws. var. ponderosa. In this study, we examined bark beetle responses to creation of midseral (low diversity) and late-seral stages (high diversity) and the application of prescribed fire on 12 experimental units ranging in size from 76 to 136 ha. A total of 9500 (5.0% of all trees) Pinus and Abies trees died 2 years after treatment of which 28.8% (2733 trees) was attributed to bark beetle colonization. No significant difference in the mean percentage of trees colonized by bark beetles was found between low diversity and high diversity. The application of prescribed fire resulted in significant increases in bark beetle caused tree mortality (all species) and for western pine beetle, Dendroctonus brevicomis LeConte, mountain pine beetle, Dendroctonus ponderosae Hopkins, Ips spp., and fir engraver, Scolytus ventralis LeConte, individually. Approximately 85.6% (2339 trees) of all bark beetle caused tree mortality occurred on burned split plots. The implications of these and other results to sustainable forest management are discussed.


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