Herbaceous plants in the understory of a pitch canker-affected Pinus radiata plantation are endophytically infected with Fusarium circinatum

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.

Download Full-text

Rates of pitch canker induced seedling mortality among Pinus radiata families varying in levels of genetic resistance to Gibberella circinata (anamorph Fusarium circinatum)

Forest Ecology and Management ◽

10.1016/j.foreco.2006.07.011 ◽

2006 ◽

Vol 235 (1-3) ◽

pp. 14-17 ◽

Cited By ~ 44

Author(s):

Brenna J. Aegerter ◽

Thomas R. Gordon

Keyword(s):

Pinus Radiata ◽

Genetic Resistance ◽

Pitch Canker ◽

Fusarium Circinatum ◽

Seedling Mortality ◽

Gibberella Circinata

Download Full-text

SEMIOCHEMICALS FROM THREE SPECIES OF PITYOPHTHORUS (COLEOPTERA: SCOLYTIDAE): IDENTIFICATION AND FIELD RESPONSE

The Canadian Entomologist ◽

10.4039/ent132889-6 ◽

2000 ◽

Vol 132 (6) ◽

pp. 889-906 ◽

Cited By ~ 39

Author(s):

Paul L. Dallara ◽

Steven J. Seybold ◽

Holger Meyer ◽

Till Tolasch ◽

Wittko Francke ◽

...

Keyword(s):

Aggregation Pheromone ◽

Pinus Radiata ◽

Causal Agent ◽

Pheromone Component ◽

Pitch Canker ◽

Fusarium Circinatum ◽

Canker Disease ◽

Porapak Q ◽

Field Response ◽

Opposite Sex

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.

Download Full-text

Incidence of the pitch canker pathogen and associated insects in intact and chipped Monterey pine branches

The Canadian Entomologist ◽

10.4039/ent13447-1 ◽

2002 ◽

Vol 134 (1) ◽

pp. 47-58 ◽

Cited By ~ 18

Author(s):

William R. McNee ◽

David L. Wood ◽

Andrew J. Storer ◽

Thomas R. Gordon

Keyword(s):

Temporal Variation ◽

Pinus Radiata ◽

Pitch Canker ◽

Fusarium Circinatum ◽

Coastal Site ◽

Monterey Pine ◽

Canker Pathogen ◽

The Mean ◽

Emerging Insects

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.

Download Full-text

Twig beetles, Pityophthorus spp. (Coleoptera: Scolytidae), as vectors of the pitch canker pathogen in California

The Canadian Entomologist ◽

10.4039/n03-118 ◽

2004 ◽

Vol 136 (5) ◽

pp. 685-693 ◽

Cited By ~ 34

Author(s):

Andrew J. Storer ◽

David L. Wood ◽

Thomas R. Gordon

Keyword(s):

Pinus Radiata ◽

Fungal Spores ◽

Pitch Canker ◽

Fusarium Circinatum ◽

Monterey Pine ◽

Canker Pathogen ◽

Disease Free

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.

Download Full-text

Compost Tea Reduces the Susceptibility of Pinus radiata to Fusarium circinatum in Nursery Production

Phytopathology ◽

10.1094/phyto-04-19-0139-r ◽

2020 ◽

Vol 110 (4) ◽

pp. 813-821

Author(s):

M. Otero ◽

I. Salcedo ◽

K. Txarterina ◽

C. González-Murua ◽

M. K. Duñabeitia

Keyword(s):

Pinus Radiata ◽

Plant Pathogens ◽

Pitch Canker ◽

Fusarium Circinatum ◽

Compost Tea ◽

Nursery Production ◽

Defense Related Gene ◽

Current Production ◽

Pathogen Colonization

Nutrition is one of the factors that most limits forestry plant growth; thus, current production in nurseries is based on conventional fertilization focused on enhancing vigor. However, an excessive intake of mineral nitrogen can cause morphological imbalances and the formation of more succulent tissues which, consequently, increase susceptibility to plant pathogens. Fusarium circinatum is the causal agent of pitch canker in plants of the Pinus genus, with Pinus radiata being the species most susceptible to this disease. This study compares the response of P. radiata seedlings to infection by F. circinatum as influenced by two fertilizers—conventional and aerated compost tea (ACT)—applied during the nursery phase. The potential of ACT against F. circinatum was first tested in vitro, where it was found to inhibit the pathogen’s mycelial growth and conidial germination. In the greenhouse, infected plants fertilized with ACT exhibited less severe internal and external symptoms of pitch canker and lower levels of pathogen colonization of both stems and needles than with conventional fertilizer. An analysis of the hormone content and defense-related gene expression shows greater salicylic acid production and phenylalanine ammonium-lyase and chalcone synthase expression in ACT-fertilized pine. All of the parameters assessed are consistent in showing that biofertilization with ACT reduces the susceptibility of pine seedlings to the disease compared with conventional fertilization.

Download Full-text

The Effect of Resin and Monoterpenes on Spore Germination and Growth in Fusarium circinatum

Phytopathology ◽

10.1094/phyto-02-14-0027-r ◽

2015 ◽

Vol 105 (1) ◽

pp. 119-125 ◽

Cited By ~ 10

Author(s):

S. L. Slinski ◽

F. Zakharov ◽

T. R. Gordon

Keyword(s):

Pinus Radiata ◽

Spore Germination ◽

Direct Contact ◽

Radial Growth ◽

Mycelial Growth ◽

Dry Weight ◽

Pitch Canker ◽

Fusarium Circinatum ◽

Saturated Atmosphere ◽

Germination And Growth

Resin obtained from Pinus radiata and five monoterpene components of resin (limonene, α-pinene, β-pinene, camphene, and myrcene) were tested to determine their effects on mycelial growth and germination and survival of spores of Fusarium circinatum, the cause of pitch canker in pine, and F. temperatum, which is interfertile with F. circinatum but not pathogenic to pine. Averaged across all treatments, F. temperatum sustained the greatest reduction in radial growth (16.9 ± 0.02% of control). The greatest reduction in dry weight also occurred in F. temperatum (11.7 ± 0.01% of control), and all isolates of F. circinatum were significantly less affected (P < 0.05). Spore germination rates in a saturated atmosphere of monoterpenes were relatively high for all tested isolates but, when placed in direct contact with resin, spore survival was significantly greater for F. circinatum than for F. temperatum. Our results are consistent with the hypothesis that greater tolerance of resin is one factor distinguishing F. circinatum from the nonpathogenic F. temperatum. However, differential tolerance of monoterpene components of resin is not sufficient to explain the observed variation in virulence to pine in F. circinatum.

Download Full-text

Fungal Communities Associated with Bark Beetles in Pinus radiata Plantations in Northern Spain Affected by Pine Pitch Canker, with Special Focus on Fusarium Species

Forests ◽

10.3390/f9110698 ◽

2018 ◽

Vol 9 (11) ◽

pp. 698 ◽

Cited By ~ 6

Author(s):

Diana Bezos ◽

Pablo Martínez-Álvarez ◽

Antonio Sanz-Ros ◽

Jorge Martín-García ◽

M. Fernandez ◽

...

Keyword(s):

Bark Beetle ◽

Pinus Radiata ◽

Bark Beetles ◽

Fusarium Species ◽

Pathogenic Fungi ◽

Fungal Communities ◽

Special Focus ◽

Pitch Canker ◽

Fusarium Circinatum ◽

Northern Spain

Fusarium spp., as well as other endophytic or pathogenic fungi that form communities, have been reported to be phoretically associated with bark beetles (Coleoptera; Scolytinae) worldwide. This applies to Fusarium circinatum Nirenberg and O’Donnell, the causal agent of pine pitch canker (PPC), which threatens Pinus radiata D. Don plantations in northern Spain. The main objective of this study was to study the fungal communities associated with bark beetles and their galleries in stands affected by PPC, with special attention given to Fusarium species. Funnel traps and logs were placed in a P. radiata plot known to be affected by F. circinatum. The traps were baited with different attractants: four with (E)-pityol and six with ethanol and α-Pinene. In addition, fresh green shoots with Tomicus piniperda L. feeding galleries were collected from the ground in 25 P. radiata plots affected by PPC. Extracts of whole insects and gallery tissues were plated on agar medium to isolate and identify the associated fungi. A total of 24 different fungal species were isolated from the bark beetle galleries constructed in logs and shoots, while 18 were isolated from the insect exoskeletons. Ten different Fusarium species were isolated from tissue and insects. Fusarium circinatum was isolated from bark beetle exoskeletons (1.05% of the Pityophthorus pubescens Marsham specimens harboured F. circinatum) and from the galleries (3.5% of the T. piniperda feeding galleries harboured the pathogen). The findings provide information about the fungal communities associated with bark beetles in P. radiata stands in northern Spain.

Download Full-text