Transmission of Bursaphelenchus xylophilus between Monochamus alternatus and Monochamus saltuarius through interspecific mating behaviour

2019 ◽  
Vol 143 (4) ◽  
pp. 483-486 ◽  
Author(s):  
Katsumi Togashi ◽  
Süleyman Akbulut ◽  
Koji Matsunaga ◽  
Hiroyuki Sugimoto ◽  
Kenichi Yanagisawa
Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 453
Author(s):  
Zi-Yi Zhang ◽  
Jia-Yin Guan ◽  
Yu-Rou Cao ◽  
Xin-Yi Dai ◽  
Kenneth B. Storey ◽  
...  

We determined the mitochondrial gene sequence of Monochamus alternatus and three other mitogenomes of Lamiinae (Insect: Coleoptera: Cerambycidae) belonging to three genera (Aulaconotus, Apriona and Paraglenea) to enrich the mitochondrial genome database of Lamiinae and further explore the phylogenetic relationships within the subfamily. Phylogenetic trees of the Lamiinae were built using the Bayesian inference (BI) and maximum likelihood (ML) methods and the monophyly of Monochamus, Anoplophora, and Batocera genera was supported. Anoplophora chinensis, An. glabripennis and Aristobia reticulator were closely related, suggesting they may also be potential vectors for the transmission of the pine wood pathogenic nematode (Bursaphelenchus xylophilus) in addition to M. alternatus, a well-known vector of pine wilt disease. There is a special symbiotic relationship between M. alternatus and Bursaphelenchus xylophilus. As the native sympatric sibling species of B. xylophilus, B. mucronatus also has a specific relationship that is often overlooked. The analysis of mitochondrial gene expression aimed to explore the effect of B. mucronatus on the energy metabolism of the respiratory chain of M. alternatus adults. Using RT-qPCR, we determined and analyzed the expression of eight mitochondrial protein-coding genes (COI, COII, COIII, ND1, ND4, ND5, ATP6, and Cty b) between M. alternatus infected by B. mucronatus and M. alternatus without the nematode. Expression of all the eight mitochondrial genes were up-regulated, particularly the ND4 and ND5 gene, which were up-regulated by 4–5-fold (p < 0.01). Since longicorn beetles have immune responses to nematodes, we believe that their relationship should not be viewed as symbiotic, but classed as parasitic.


Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 114
Author(s):  
Yang Wang ◽  
Mingxia Jin ◽  
Lichao Wang ◽  
Ailin Yu ◽  
Guai Xie ◽  
...  

In order to study the key gene in internal causes of pinewood nematode (PWN), Bursaphelenchus xylophilus, a departure from its vector beetle, Monochamus alternatus, we collected PWNs extracted from newly emerged M. alternatus and beetles 7 days after emergence. The total RNAs of the two groups of PWNs were extracted, transcriptomes sequencing was performed, and gene expression differences between the two groups of PWN were analyzed. It was found that the expression of the choline-phosphate cytidylyltransferase gene (pcyt-1) was markedly up-regulated. After inhibition of pcyt-1 expression by RNA interference, the rate of lipid degradation in PWN decreased significantly, and the motility of PWN also decreased significantly. The analysis identified that phosphatidylcholine could promote the emulsification and degradation of neutral lipid granules in PWN, which provides sufficient energy for PWN departure from M. alternatus. The up-regulation of the gene pcyt-1 is an important internal factor for PWN departure from its vector.


Author(s):  
Yang Wang ◽  
Fengmao Chen ◽  
Lichao Wang ◽  
Lifeng Zhou ◽  
Juan Song

AbstractIn order to study the causes of pine wood nematode (PWN) departure from Monochamus alternatus, the effects of the feeding behavior of M. alternatus on the start date of the departure of PWN were studied. The start date of the departure of PWN carried by the directly fed M. alternatus was 5—13 d after beetle emergence, mainly concentrated within 6—10 d, with a mean (±SD) of 8.02 ± 1.96 d. The start date of the departure of PWN carried by the M. alternatus fed after starvation was 5—14 d after beetle emergence, mainly concentrated within 6—9 d, with a mean of 7.76 ± 2.28 d. The results show that there was no significant difference in the start departure date of PWN between the two treatments. This shows that the feeding behavior of M. alternatus is not the trigger for PWN departure. At the same time, it was found that the motility of the PWN carried by M. alternatus at 8 d after emergence was significantly greater than that of the PWN carried by the newly emerged M. alternatus. And the PWN carried by M. alternatus at 8 d after emergence was extracted more easily than the PWN carried by newly emerged beetles. These results show that greater motility was associated with easier departure of PWN from M. alternatus. In addition, transcriptome sequencing found that the level of oxidative phosphorylation metabolism of PWN carried by beetles at 8 d after emergence was significantly higher than that in the PWN carried by newly emerged beetle. High oxidative phosphorylation was associated with increased energy production and motility by the PWN and were the internal cause of the start of nematode departure.


Nematology ◽  
2003 ◽  
Vol 5 (6) ◽  
pp. 843-849 ◽  
Author(s):  
Shota Jikumaru ◽  
Katsumi Togashi

Abstract Bursaphelenchus mucronatus is closely related to Bursaphelenchus xylophilus, the causative agent of pine wilt disease. Both nematodes are transmitted between host pine trees as the fourth-stage dispersal juveniles (JIV) by insect vectors. After the invasion of Japan by B. xylophilus, B. mucronatus, native to Japan, appears to have been replaced in the pine forests during the spread of the disease. To help understand this species replacement, the number of JIV carried by an insect vector (the initial nematode load) was compared between the two nematode species by using the beetle, Monochamus alternatus, in the laboratory. The initial load of B. mucronatus was significantly smaller than that of B. xylophilus although the number of third-stage dispersal juveniles (JIII) concentrated at the pupal chambers did not differ. Statistical analysis showed that the proportion of JIII moulting to JIV was the most important among three components explaining the difference in the initial load of B. mucronatus while the number of JIII concentrated at the pupal chamber was the most important for B. xylophilus. The phoretic affinity between the nematode and its vector is discussed in relation to its role in the species replacement.


Nematology ◽  
2010 ◽  
Vol 12 (5) ◽  
pp. 721-729 ◽  
Author(s):  
Noritoshi Maehara ◽  
Masahiko Tokoro

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.


Nematology ◽  
2001 ◽  
Vol 3 (5) ◽  
pp. 455-461 ◽  
Author(s):  
Noritoshi Maehara ◽  
Kazuyoshi Futai

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.


2014 ◽  
Vol 147 (5) ◽  
pp. 628-634
Author(s):  
M. Xu ◽  
F.Y. Xu ◽  
Y.P. Liu ◽  
Y.S. Pan ◽  
X.Q. Wu

AbstractThe pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (Aphelenchida: Parasitaphelenchidae), is a major disease of pines forests in China. Its vector, Monochamus alternatus Hope (Coleoptera: Cerambycidae), has been the focus of an intensive study to improve the efficiency of the parasitoid Scleroderma guani Xiao and Wu (Hymenoptera: Bethylidae) by using the parasitoid both as a larval parasitoid in its own right and additionally as a vector for the entomophagous pathogen Metarhizium anisopliae (Metchnikoff) Sorokin (Clavicipitaceae). Twenty-one M. anisopliae strains were screened and the best four tested for sporulation capabilities at a range of temperatures. The best strain was then evaluated at several sporulation concentrations to define the lethal concentration 50 (LC50) against the larvae of M. alternatus. Scleroderma guani was inoculated with the best strain and tested against larvae of M. alternatus, which were constrained singly in glass vials. Three S. guani females per vial infected with M. anisopliae (strain 789) were shown to cause the death of 100% of the M. alternatus larvae they were exposed to as compared exposures to just one or two infected S. guani females per vial. This demonstrates a successful interaction of two biocontrol agents for the control of the pinewood nematode vector M. alternatus.


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