scholarly journals Variation in Rates of Spore Deposition of Fusarium circinatum, the Causal Agent of Pine Pitch Canker, Over a 12-Month-Period at Two Locations in Northern California

2008 ◽  
Vol 98 (1) ◽  
pp. 137-143 ◽  
Author(s):  
M. Garbelotto ◽  
T. Smith ◽  
W. Schweigkofler

Patterns of spore deposition by Fusarium circinatum, the causal agent of pine pitch canker (PPC) of Monterey pine (Pinus radiata) and other conifers, were studied between May 2003 and April 2004 at two sites in Northern California using a novel spore trapping method combined with a real-time polymerase chain reaction (PCR) approach. At each study site, two plots were sampled by placing spore traps at 100 m intervals along transects 600 m in length. The air was sampled continuously by exchanging the spore traps every 2 weeks. The spore deposition rate (DR), ranged from 0 to 1.3 × 105 spores m–2. Spores were detected throughout the year, with higher trapping frequencies (TF) during the rainy season (November to April), than during the dry season (May to October). The detection of spores on traps at distances larger than 200 m from any Monterey pine, suggests at least midrange aerial dispersal. Finally, different inoculum loads were associated with trees displaying different levels of disease symptoms, suggesting infectiousness of the pathogen varies as the disease progresses. This study represents one of the first documenting continuous inoculum pressure values over an entire year for a forest pathogen, and provides important epidemiological information that will be invaluable in the development of disease progression models.

Mycologia ◽  
2000 ◽  
Vol 92 (6) ◽  
pp. 1085 ◽  
Author(s):  
Karen Wikler ◽  
Thomas R. Gordon ◽  
Sharon L. Clark ◽  
Michael J. Wingfield ◽  
Henriette Britz

2002 ◽  
Vol 134 (4) ◽  
pp. 519-528 ◽  
Author(s):  
Andrew J. Storer ◽  
David L. Wood ◽  
Thomas R. Gordon

AbstractIps paraconfusus Lanier is a vector of the pitch canker fungus, Fusarium circinatum Nirenberg and O’Donnell, in California. Multiple infections of Monterey pine, Pinus radiata D. Don. (Pinaceae), branches and main stems appear to predispose trees to infestation by I. paraconfusus. The effect of cankers produced in response to F. circinatum on oviposition and gallery construction was investigated. Introduction of beetles into artificially induced or naturally occurring cankers was less likely to result in oviposition and resulted in shorter galleries than introductions into logs without cankers. Of all adults that produced eggs, the mean number of eggs per adult was no different in logs with cankers than in canker-free logs; however, the distance across the grain from the introduction point to the first egg was greater for adults introduced into cankers than for adults introduced away from cankers. These results indicate that the pitch canker pathogen has a negative effect on I. paraconfusus, as cankers produced in response to the pathogen are unsuitable for exploitation by the insect.


2000 ◽  
Vol 132 (6) ◽  
pp. 889-906 ◽  
Author(s):  
Paul L. Dallara ◽  
Steven J. Seybold ◽  
Holger Meyer ◽  
Till Tolasch ◽  
Wittko Francke ◽  
...  

AbstractAnalyses of pentane extracts of frass, whole beetles, and volatiles trapped on Porapak-Q from Pityophthorus Eichhoff spp. fed on Pinus radiata D. Don demonstrated that (E)-pityol [2-(1-hydroxy-1-methylethyl)-5-methyltetrahydrofuran] was produced by male Pityophthorus carmeli Swaine, female Pityophthorus nitidulus (Mannerheim), and female Pityophthorus setosus Blackman. (E)-(−)-Conophthorin) [(5S,7S)-(−)-7-methyl-1,6-dioxaspiro[4.5]decane] was produced by male P. carmeli and male P. nitidulus. Only the (2R,5S)-(+) stereoisomer of (E)-pityol was produced by male P. carmeli and female P. setosus. In field bioassays in central coastal California, P. setosus was attracted to (E)-(+)-pityol, whereas P. carmeli responded only to a combination of (E)-(−)-conophthorin and (E)-(+)-pityol. Male P. setosus and female P. carmeli responded to these treatments with larger numbers than opposite-sex conspecifics. (E)-(−)-Conophthorin alone did not attract species of Pityophthorus but significantly reduced catches of P. setosus to (E)-(+)-pityol. Lasconotus pertenuis Casey (Coleoptera: Colydiidae) and Ips mexicanus (Hopkins) (Coleoptera: Scolytidae) were attracted to a combination of (E)-(−)-conophthorin and (E)-(+)-pityol, and showed a trend for attraction to all (E)-(−)-conophthorin-containing treatments. (E)-(−)-Pityol was neither attractive nor interruptive for any taxon. (E)-(+)-Pityol is shown to be an aggregation pheromone component for P. carmeli and P. setosus. (E)-(−)-Conophthorin functions as a pheromone component for P. carmeli and may also function as a synomone that decreases competition of P. carmeli and P. nitidulus with P. setosus and as a kairomone for L. pertenuis. These semiochemicals have been useful in studying relationships among twig insects and the pathogen Fusarium circinatum (Nirenberg and O’Donnell), causal agent of pitch canker disease in P. radiata.


2004 ◽  
Vol 70 (6) ◽  
pp. 3512-3520 ◽  
Author(s):  
Wolfgang Schweigkofler ◽  
Kerry O'Donnell ◽  
Matteo Garbelotto

ABSTRACT Pinus radiata (Monterey pine), a tree native to coastal California and Mexico, is widely planted worldwide for timber production. A major threat to Monterey pine plantations is the fungal disease pine pitch canker, caused by Fusarium circinatum (Hypocreales). We present a novel trapping approach using filter paper in combination with a rapid molecular method to detect the presence of inoculum in the air. The assay is also useful for diagnosing the presence of the pathogen on plants. The test is based on the F. circinatum specific primer pair CIRC1A-CIRC4A, which amplifies a 360-bp DNA fragment in the intergenic spacer region of the nuclear ribosomal operon. Real-time PCR was used to calculate the number of fungal spores present in each reaction mixture by comparing the threshold cycle (Ct) of unknown spore samples to the Ct values of standards with known amounts of F. circinatum spores. The filter paper method allows prolonged and more sensitive spore sampling in the field compared to traditional traps using petri dishes filled with selective medium. A field test at two sites in coastal California infested with pine pitch canker was carried out during the summer and fall of 2002. Spore counts were in the range of ca. 1 � 103 to ca. 7 � 105/m2, with the highest spore counts in the fall, suggesting a seasonal fluctuation.


2014 ◽  
Vol 39 (3) ◽  
pp. 210-216 ◽  
Author(s):  
Ludwig H. Pfenning ◽  
Sarah da Silva Costa ◽  
Maruzanete Pereira de Melo ◽  
Hélcio Costa ◽  
José Aires Ventura ◽  
...  

2002 ◽  
Vol 134 (1) ◽  
pp. 47-58 ◽  
Author(s):  
William R. McNee ◽  
David L. Wood ◽  
Andrew J. Storer ◽  
Thomas R. Gordon

AbstractIn a 2-year study of Monterey pine, Pinus radiata D. Don (Pinaceae), infected with pitch canker, caused by Fusarium circinatum Nirenberg and O'Donnell, less than 2% of symptomatic branches with green foliage were colonized by twig beetles in the genus Pityophthorus Eichhoff (Coleoptera: Scolytidae), whereas approximately 50% of branches with yellow and red foliage were colonized. More Pityophthorus spp. emerged from yellow branches (mean ± SE = 12.1 ± 1.7 per 30 cm) than from red branches (6.9 ± 0.9) at an inland study site (Oakland) but, at a coastal site (Pebble Beach), the means were not significantly different (4.3 ± 0.6 and 3.8 ± 0.7). The mean phoresy rate of all emerging insects was higher at Pebble Beach (17.7 ± 0.6%) than at Oakland (5.3 ± 0.2%). At both sites, there was considerable temporal variation in the proportion of branches colonized by twig beetles, mean numbers of emerging twig beetles, and phoresy rates of emerging insects. Chipping branches reduced the emergence of Pityophthorus spp. and associates by approximately 95%, compared with emergence from intact branches. The pathogen was isolated from 1-year-old branches and chips in up to 68% of samples, but was only recovered from 3-year-old branches in 1 of 46 sampled. It is recommended that recent branch cuttings and chips originating from symptomatic trees not be transported to areas that are believed to be free of the disease.


2005 ◽  
Vol 137 (3) ◽  
pp. 337-349 ◽  
Author(s):  
Nadir Erbilgin ◽  
Andrew J. Storer ◽  
David L. Wood ◽  
Thomas R. Gordon

AbstractPitch canker of pines (Pinus spp.) and Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) (Pinaceae) is caused by the fungus Fusarium circinatum Nirenberg et O'Donnell. In California, infections by F. circinatum occur largely through wounds caused by insects. Field experiments were initiated to determine whether the colonization activities of twig beetles, Pityophthorus spp. (Coleoptera: Scolytidae), could explain the incidence of pitch canker on Monterey pine (P. radiata D. Don), Bishop pine (P. muricata D. Don), ponderosa pine (P. ponderosa var. ponderosa Dougl.), knobcone pine (P. attenuata Lemm.), and Douglas-fir. Asymptomatic branches were cut from each of four pairs of tree species (Monterey–Bishop, Monterey–ponderosa, Monterey–knobcone, Monterey–Douglas-fir) at four sites and attached to the lower canopy of both heterospecific and conspecific host trees (total of four combinations per pair). After 10 weeks, branches were collected and placed in rearing tubes in the laboratory. Emerging insects were identified and placed on a Fusarium-selective medium. Monterey, Bishop, and ponderosa pines were more heavily infested by Pityophthorus spp. than Douglas-fir and knobcone pine. Furthermore, more Pityophthorus beetles emerged from Monterey pine branches placed in Monterey pine canopies than from Monterey pine branches placed in Bishop or ponderosa pine canopies, indicating that reduced emergence (colonization) was caused by the hetero specific host. Relatively fewer insects emerged from sites containing either Monterey and knobcone pines or Monterey pine and Douglas-fir. Fusarium circinatum was not isolated from emerging Pityophthorus spp. Susceptibility of the five host species, based on mean lesion lengths resulting from mechanical inoculations, varied significantly. The longest lesions were on Monterey pine and the shortest were on ponderosa pine and Douglas-fir. The low incidence of pitch canker on Douglas-fir and ponderosa pine in nature compared with that on Monterey, Bishop, and knobcone pines may be explained by the low colonization by twig beetles and the greater resistance of Douglas-fir and ponderosa pine to this disease, compared with the other three hosts.


2014 ◽  
Vol 72 (2) ◽  
pp. 169-181 ◽  
Author(s):  
Timo Möykkynen ◽  
Paolo Capretti ◽  
Timo Pukkala

2004 ◽  
Vol 136 (5) ◽  
pp. 685-693 ◽  
Author(s):  
Andrew J. Storer ◽  
David L. Wood ◽  
Thomas R. Gordon

AbstractTwig beetles in the genus Pityophthorus Eichhoff are known to be associated with the pitch canker pathogen, Fusarium circinatum, in California. Phoresy of the pathogen on these species has been reported to occur when insects emerge from diseased branches and when they infest disease-free, cut branch tips. To demonstrate that twig beetles can vector the pathogen, studies of phoresy and transmission were conducted in a native Monterey pine, Pinus radiata D. Don (Pinaceae), forest. Phoresy was confirmed for both Pityophthorus setosus Blackman and Pityophthorus carmeli Swaine, and P. setosus was shown to vector the pitch canker pathogen when contaminated with fungal spores and caged onto Monterey pine branches. When attractive baits were used to increase visitation to Monterey pines by P. setosus, baited trees were more likely to develop pitch canker than unbaited trees even though the beetles did not tunnel into the host to develop egg galleries. Therefore, twig beetles are competent as vectors of the pitch canker pathogen, and their vectoring activity, though requiring a wound, does not require that they establish egg galleries in the host.


Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 724 ◽  
Author(s):  
Rein Drenkhan ◽  
Beccy Ganley ◽  
Jorge Martín-García ◽  
Petr Vahalík ◽  
Kalev Adamson ◽  
...  

Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats of Pinus spp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of trees, from emerging seedlings to mature trees. Despite the importance of PPC, the global distribution of F. circinatum is poorly documented, and this problem is also true of the hosts within countries that are affected. The aim of this study was to review the global distribution of F. circinatum, with a particular focus on Europe. We considered (1) the current and historical pathogen records, both positive and negative, based on confirmed reports from Europe and globally; (2) the genetic diversity and population structure of the pathogen; (3) the current distribution of PPC in Europe, comparing published models of predicted disease distribution; and (4) host susceptibility by reviewing literature and generating a comprehensive list of known hosts for the fungus. These data were collated from 41 countries and used to compile a specially constructed geo-database. A review of 6297 observation records showed that F. circinatum and the symptoms it causes on conifers occurred in 14 countries, including four in Europe, and is absent in 28 countries. Field observations and experimental data from 138 host species revealed 106 susceptible host species including 85 Pinus species, 6 non-pine tree species and 15 grass and herb species. Our data confirm that susceptibility to F. circinatum varies between different host species, tree ages and environmental characteristics. Knowledge on the geographic distribution, host range and the relative susceptibility of different hosts is essential for disease management, mitigation and containment strategies. The findings reported in this review will support countries that are currently free of F. circinatum in implementing effective procedures and restrictions and prevent further spread of the pathogen.


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