Variations in life history parameters and their influence on rate of population increase of different pathogenic isolates of the pine wood nematode, Bursaphelenchus xylophilus

Nematology ◽  
2005 ◽  
Vol 7 (3) ◽  
pp. 459-467 ◽  
Author(s):  
Yu Wang ◽  
Kazuo Suzuki ◽  
Daisuke Sakaue ◽  
Toshihiro Yamada
Keyword(s):  
Life History ◽  
Population Size ◽  
Botrytis Cinerea ◽  
Generation Time ◽  
Bursaphelenchus Xylophilus ◽  
Egg Laying ◽  
Population Increase ◽  
Pine Wood Nematode ◽  
Life History Parameters ◽  
Pine Trees

AbstractTwo virulent isolates and two avirulent isolates of Bursaphelenchus xylophilus and one isolate of B. mucronatus were used to investigate the relationships between life history parameters, rate of population increase and virulence. The results showed that on fungal cultures of Botrytis cinerea, virulent B. xylophilus completed one generation much faster than did avirulent B. xylophilus and B. mucronatus. There was a tendency that virulent B. xylophilus isolates laid more eggs during the egg laying period than did avirulent populations. Shorter generation time and higher fecundity resulted in a higher rate of population increase. Generation time and fecundity were primary factors determining rate of population increase. Difference in rate of population increase is closely related to variation of virulence: virulent B. xylophilus increased population size at the fastest rate, avirulent B. xylophilus was slower, and B. mucronatus was slowest. It is assumed that similar variations in life history parameters and rate of population increase are also expressed in pine trees and help to explain variation of virulence in the field.

Influence of fungi on multiplication and distribution of the pine wood nematode, Bursaphelenchus xylophilus, in axenized Pinus thunbergii cuttings

Nematology ◽  
2005 ◽  
Vol 7 (6) ◽  
pp. 809-817 ◽  
Author(s):  
Kazuo Suzuki ◽  
Daisuke Sakaue ◽  
Toshihiro Yamada ◽  
Yu Wang
Keyword(s):  
Population Size ◽  
Early Stage ◽  
Bursaphelenchus Xylophilus ◽  
Pinus Thunbergii ◽  
Disease Development ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Inoculation Site ◽  
Fungal Hyphae ◽  
Close Relationship

AbstractInfluence of fungi on multiplication and distribution of the pine wood nematode (PWN), Bursaphelenchus xylophilus, was investigated in Pinus thunbergii cuttings. Axenized nematodes and/or one of two fungi isolated from healthy and PWN-killed P. thunbergii were inoculated together into autoclaved cuttings. A close relationship between the existence and distribution of fungal hyphae, and the multiplication and distribution of PWN was observed. The PWN did not multiply when only axenized nematodes were inoculated in the absence of fungi. When fungi were present, PWN population size increased markedly. The number of nematodes was high at sites where fungal hyphae were distributed. It is suggested that the restriction of a large portion of the nematode population near the inoculation site during the early stage of disease development is closely related to restricted distribution of fungal hyphae.

Effect of unsaturated fatty acids around pupal chambers of Monochamus alternatus (Coleoptera: Cerambycidae) and Acanthocinus orientalis (Coleoptera: Cerambycidae) on the number of Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) carried by the beetles

Nematology ◽  
2010 ◽  
Vol 12 (5) ◽  
pp. 721-729 ◽  
Author(s):  
Noritoshi Maehara ◽  
Masahiko Tokoro
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Chemical Compounds ◽  
Bursaphelenchus Xylophilus ◽  
Gas Chromatography Mass Spectrometry ◽  
Pine Wood Nematode ◽  
Monochamus Alternatus ◽  
Significant Relationships ◽  
Pine Trees

Abstract Several chemical compounds, e.g., linoleic and oleic acids, have been reported to be attractive to the pine wood nematode, Bursaphelenchus xylophilus, in previous studies. To examine the effects of fatty acids on the number of nematodes carried by Monochamus alternatus and Acanthocinus orientalis, unsaturated fatty acids (linoleic, oleic and hexadecenoic acids) and saturated fatty acids (palmitic and stearic acids) around the pupal chambers of individual beetles of the two species were analysed using gas chromatography-mass spectrometry. The number of nematodes carried by individual M. alternatus was large, averaging 1628 (range 2 to 27 200), whilst A. orientalis carried no nematodes. There was no difference in the concentration of linoleic acid around the pupal chambers of M. alternatus and A. orientalis, and the concentration of oleic acid around Monochamus chambers was less than that around Acanthocinus chambers. There were no clear significant relationships between the concentration of linoleic or oleic acids around Monochamus pupal chambers and the numbers of nematodes carried by individual Monochamus beetles emerging from the chambers. It was concluded that the concentration of unsaturated fatty acids around pupal chambers in wilt-killed pine trees could not explain the differences in the numbers of nematodes carried by M. alternatus and by A. orientalis, and the differences in the numbers of nematodes carried by individual Monochamus beetles.

Importance of the Variation in Life History Parameters of Atlantic Salmon (Salmo salar)

1985 ◽  
Vol 42 (3) ◽  
pp. 615-618 ◽  
Author(s):  
Richard L. Saunders ◽  
Charles B. Schom
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Population Size ◽  
Salmo Salar ◽  
Great Variability ◽  
Mature Male ◽  
Life History Parameters ◽  
Atlantic Salmon Salmo Salar ◽  
Sexually Mature ◽  
Mature Male Parr

Atlantic salmon (Salmo salar) demonstrate great variability in their life history; individuals from a given year-class can spawn during several years and can, therefore, breed with salmon from other year-classes. Atlantic salmon can mature after 1–4 sea-winters and some males mature as parr, during the second through fifth years, before going to sea. Salmon may survive to spawn more than once; some spawn several times. This variability in life history may be a safeguard against loss of small stocks through several successive years of reproductive failure, since nonspawning individuals in the river or at sea could spawn in subsequent years. Spawning populations are frequently quite small. The effective spawning population size may be potentially much larger, however, since members of several year-classes, including sexually mature male parr and anadromous adults of various ages, contribute to spawning. The level of inbreeding may be relatively low, since a number of year-classes, each with different sets of parents, are represented during spawning.

Presence of the cerambycid beetles Psacothea hilaris and Monochamus alternatus affecting the life cycle strategy of Bursaphelenchus xylophilus

Nematology ◽  
2001 ◽  
Vol 3 (5) ◽  
pp. 455-461 ◽  
Author(s):  
Noritoshi Maehara ◽  
Kazuyoshi Futai
Keyword(s):  
Life History ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Fourth Stage ◽  
Monochamus Alternatus ◽  
The Third ◽  
Life Cycle Strategy ◽  
Pine Trees ◽  
History Of ◽  
Cerambycid Beetles

AbstractAlthough fourth-stage dispersal juveniles (JIV) of Bursaphelenchus xylophilus, the pinewood nematode (PWN), developed in the presence of both Monochamus alternatus and Psacothea hilaris, the numbers and the percentage of JIV were far higher in the presence of the former than of the latter. JIV first appeared 7 days after pupation of M. alternatus and the number increased from the day of beetle eclosion to the third day thereafter, then remained stable. We conclude that the presence of specific vectors affects both the life history of the PWN and the numbers of nematodes carried by vectors emerging from killed pine trees.

Reproductive traits ofMonochamus galloprovincialis(Coleoptera: Cerambycidae) under laboratory conditions

2006 ◽  
Vol 96 (3) ◽  
pp. 289-294 ◽  
Author(s):  
P. Naves ◽  
E. de Sousa ◽  
J.A. Quartau
Keyword(s):  
Secondary Forest ◽  
Reproductive Potential ◽  
Principal Component ◽  
Reproductive Traits ◽  
Bursaphelenchus Xylophilus ◽  
Egg Laying ◽  
Large Individual ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Laboratory Conditions

AbstractThe pine sawyerMonochamus galloprovincialis(Olivier) is the vector of the introduced pine wood nematodeBursaphelenchus xylophilus(Steiner & Bührer) Nickle in Portugal, and until recently was considered a secondary forest insect. Under laboratory conditions, a study of biological and reproductive traits of 37 insect pairs was conducted. The longevity of both sexes was similar, being 61.2±6.5 days for males and 64.0±6.3 days for females (mean±SE). Sixteen small-sized insects (22% of the population) died within 20 days and before starting to reproduce. The sexual maturation period (without egg laying) was 20.4±0.7 days (mean±SE), while the oviposition period lasted 54.0±4.2 days (mean±SE). The oviposition rate increased very quickly during the first weeks of life, peaking to almost two eggs per day during days 30–44, and gradually dropping in the following weeks. The females laid an average of 67.0±5.96 (mean±SE) eggs through their lives. The hatch rate was 92.6±1.0%; (mean±SE). There were large individual variations in longevity and fecundity parameters, and principal component analysis based on 16 morphological and biological parameters separated the breeding insects into four distinct groups. Almost half of the reproducing beetles were large-sized insects, with high longevity and fecundity traits. Overall, the reproductive potential of the Portuguese population ofM. galloprovincialisseems to be smaller than that described for otherMonochamusvectors of the pine wood nematode both in North America and Japan.

scholarly journals Management Implications for Skates and Rays Based on Analysis of Life History Parameters

2021 ◽  
Vol 8 ◽  
Author(s):  
Kwang-Ming Liu ◽  
Ya-Wen Huang ◽  
Hua-Hsun Hsu
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Principal Component ◽  
Age And Growth ◽  
Population Increase ◽  
Early Maturity ◽  
Life History Parameters ◽  
Management Measures ◽  
Group 2 ◽  
Size At Birth

The life history (age and growth and reproduction) parameters of 35 species (41 stocks) of skates and rays were analyzed using multivariate analyses. Three groups were categorized by cluster analysis (CA) based on principal component scores. Empirical equation was developed for each group to describe the relationships between the predicted a finite rate of population increase (λ′) and the life history parameters: growth coefficient (k), asymptotic length (L∞), age at maturity (Tm), annual fecundity (f/Rc), ratio between size at birth (Lb), and L∞ (Lb/L∞), and ratio between size at maturity (Lm) and L∞ (Lm/L∞). Group 1 included species with slow growth rates (k < 0.011 year–1), early maturity (Lm/L∞ < 0.62), and extended longevity (Tmax > 25 years); Group 2 included species with intermediate growth rates (0.080 year–1 < k < 0.190 year–1), intermediate longevity (17 years < Tmax < 35 years), and late maturity (Lm/L∞ > 0.60); Group 3 included species with a fast growth rate (k > 0.160 year–1), short longevity (Tmax < 23 years), and large size at birth (Lb/L∞ > 0.18). The λ′ values estimated by these empirical equations showed good agreement with those calculated using conventional demographic analysis, suggesting that this approach can be applied in the implementation of management measures for data-limited skates and rays in a precautionary manner.

scholarly journals Assessment of the PCR technique for identification of Bursaphelenchus mucronatus Mamiya & Enda 1979, B. xylophilus Steiner & Buhrer 1934 (Nickle 1970) and B. fraudulentus Rühm 1956 (Nematoda, Aphelenchoididae) in crude extract of nematodes isolated from wood

2021 ◽  
Vol 61 (4) ◽  
pp. 346-351
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Coniferous Forests ◽  
Pine Wood Nematode ◽  
Direct Examination ◽  
Pine Wood ◽  
Pine Wilt ◽  
Detection And Identification ◽  
Pine Trees

The pine wood nematode, Bursaphelenchus xylophilus Steiner & Buhrer 1934 (Nickle 1970) is the major causative agent of the pine wilt disease which has become devastating to Asian and European coniferous forests. These regions are also naturally occupied by two other native but nonpathogenic species, i.e. B. mucronatus Mamiya & Enda 1979 and B. fraudulentus Rühm 1956 which are closely related to the invasive B. xylophilus. Moreover, all these three species can colonize pine trees, and potentially be extracted from the same wood samples. Due to the cosmopolitan character and wide genetic variation within- and between existing populations the taxonomic distinction of these species based exclusively on their morphology is difficult or, almost impossible. The present quarantine regulations related to B. xylophilus require the most credible and simple methods which could allow for a possibly earliest detection and precise identification of this species in wood shipments and conifer forests stands. The main objectives of the presently reported research were to simplify the presently available procedures for possibly fast and precise detection and identification of B. xylophilus examined in the background of the remaining Bursaphelenchus species of the xylophilus group and other bacterio- and mycetophagous nematodes naturally present in the pine wood samples. The developed method is based on a direct examination of the crude nematode extract from wood samples and subsequent use of PCR technique with earlier designed specific reaction starters amplifying ITS1–28S rDNA regions.

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