The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
V M Aguiero - One of the best experts on this subject based on the ideXlab platform.
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Population characteristics and tungro transmission by Nephotettix virescens (Hemiptera: Cicadellidae) on selected resistant rice cultivars
Bulletin of Entomological Research, 1997Co-Authors: G. Dahal, H. Hibino, V M AguieroAbstract:Rice green leafhopper Nephotettix virescens (Distant) populations were collected in 1985 from fields planted with a leafhopper resistant rice, Oryza sativa cultivar IR64 in South Cotabato, Philippines. The populations were reared on IR64 for eight generations and tested on six cultivars, including susceptible TN1, moderately resistant IR26 and IR36, and resistant IR54, IR62, and IR64. Leafhoppers excreted larger amounts of basic honeydew, efficiently transmitted two tungro associated viruses, and showed greater population increase and lower nymphal mortality on all cultivars except IR62 than a greenhouse population reared on TN1. Nephotettix virescens were transferred and maintained on TN1, IR26, IR36, IR64, or a mixture of the four cultivars plus IR54 and IR56 in equal proportion. When the TN1-maintained colony was tested at the third generation, its feeding behaviour and tungro transmission rates on test cultivars were similar to those of the original population but amounts of basic honeydew excretion and the transmission rate on the resistant test cultivars were greatly reduced at the seventh or later generations. When the IR26-maintained colony was tested at the sixth, ninth, or 13th generation, it exhibited lower amounts of basic honeydew excretion on the resistant test cultivars but exhibited similar transmission efficiencies on other test cultivars. When the colonies maintained on IR36, IR64, or the cultivar mixture were tested similarly, their population characteristics and virus transmission efficiency were similar to the original population. These results indicate that N. virescens retain their ‘virulence’ to resistant cultivars when maintained on resistant cultivars, but quickly lose their ‘virulence’ when maintained on a susceptible cultivar. Colonies continuously reared on IR26, IR36 or IR64 showed ‘cross-virulence’ to many cultivars possessing a variety of genes for N. virescens resistance but often differed in feeding behaviour, virus transmission efficiency, and nymphal mortality on cultivars with the same genes for leafhopper resistance.
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rice and weed hosts of rice tungro associated viruses and leafhopper vectors
Plant Disease, 1991Co-Authors: H. Hibino, V M Aguiero, R D Daquioag, O S OpinaAbstract:Transmission of rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV) to rice and weeds by Nephotettix virescens. N. nigropictus, N. malayanus, and Recilia dorsalis was compared. N. virescens was the most efficient vector of both viruses to rice and retained them for 4 days after an acquisition access period on infected rice. N. nigropictus was less efficient but retained both viruses for 5 days. N. malayanus and R. dorsalis were the least efficient and retained both viruses for only 1 day
H. Hibino - One of the best experts on this subject based on the ideXlab platform.
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Population characteristics and tungro transmission by Nephotettix virescens (Hemiptera: Cicadellidae) on selected resistant rice cultivars
Bulletin of Entomological Research, 1997Co-Authors: G. Dahal, H. Hibino, V M AguieroAbstract:Rice green leafhopper Nephotettix virescens (Distant) populations were collected in 1985 from fields planted with a leafhopper resistant rice, Oryza sativa cultivar IR64 in South Cotabato, Philippines. The populations were reared on IR64 for eight generations and tested on six cultivars, including susceptible TN1, moderately resistant IR26 and IR36, and resistant IR54, IR62, and IR64. Leafhoppers excreted larger amounts of basic honeydew, efficiently transmitted two tungro associated viruses, and showed greater population increase and lower nymphal mortality on all cultivars except IR62 than a greenhouse population reared on TN1. Nephotettix virescens were transferred and maintained on TN1, IR26, IR36, IR64, or a mixture of the four cultivars plus IR54 and IR56 in equal proportion. When the TN1-maintained colony was tested at the third generation, its feeding behaviour and tungro transmission rates on test cultivars were similar to those of the original population but amounts of basic honeydew excretion and the transmission rate on the resistant test cultivars were greatly reduced at the seventh or later generations. When the IR26-maintained colony was tested at the sixth, ninth, or 13th generation, it exhibited lower amounts of basic honeydew excretion on the resistant test cultivars but exhibited similar transmission efficiencies on other test cultivars. When the colonies maintained on IR36, IR64, or the cultivar mixture were tested similarly, their population characteristics and virus transmission efficiency were similar to the original population. These results indicate that N. virescens retain their ‘virulence’ to resistant cultivars when maintained on resistant cultivars, but quickly lose their ‘virulence’ when maintained on a susceptible cultivar. Colonies continuously reared on IR26, IR36 or IR64 showed ‘cross-virulence’ to many cultivars possessing a variety of genes for N. virescens resistance but often differed in feeding behaviour, virus transmission efficiency, and nymphal mortality on cultivars with the same genes for leafhopper resistance.
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rice and weed hosts of rice tungro associated viruses and leafhopper vectors
Plant Disease, 1991Co-Authors: H. Hibino, V M Aguiero, R D Daquioag, O S OpinaAbstract:Transmission of rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV) to rice and weeds by Nephotettix virescens. N. nigropictus, N. malayanus, and Recilia dorsalis was compared. N. virescens was the most efficient vector of both viruses to rice and retained them for 4 days after an acquisition access period on infected rice. N. nigropictus was less efficient but retained both viruses for 5 days. N. malayanus and R. dorsalis were the least efficient and retained both viruses for only 1 day
O S Opina - One of the best experts on this subject based on the ideXlab platform.
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rice and weed hosts of rice tungro associated viruses and leafhopper vectors
Plant Disease, 1991Co-Authors: H. Hibino, V M Aguiero, R D Daquioag, O S OpinaAbstract:Transmission of rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV) to rice and weeds by Nephotettix virescens. N. nigropictus, N. malayanus, and Recilia dorsalis was compared. N. virescens was the most efficient vector of both viruses to rice and retained them for 4 days after an acquisition access period on infected rice. N. nigropictus was less efficient but retained both viruses for 5 days. N. malayanus and R. dorsalis were the least efficient and retained both viruses for only 1 day
Qisheng Song - One of the best experts on this subject based on the ideXlab platform.
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Identification and characterization of a novel rhabdovirus in green rice leafhopper, Nephotettix cincticeps.
Virus research, 2021Co-Authors: Wenxi Jia, Fei Wang, Yi Yang, Yanyuan Bao, Shan Xiao, Longfei Chen, Qisheng SongAbstract:Abstract The family Rhabdoviridae is one of the most ecological diverse groups of RNA viruses, with remarkable genome complexity and wide host range. Rhabdoviruses are discovered in many insect species, and insects, such as midges, mosquitoes, aphids and leafhoppers, act as crucial vectors for rhabdovirus transmission. Here, a novel rhabdovirus was identified in green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), a common virus vector on rice. This virus was named as Nephotettix cincticeps negative-stranded RNA virus-1 (NcNSRV-1). The genome of NcNSRV-1 is 12,361 nucleotides in length, flanked by untranslated 3’ leader and 5’ trailer. The anti-sense viral genome consists of five major structural protein genes (N, P, M, G and L), which shares a typical architecture with the family Rhabdoviridae. An additional gene, P6, is interposed between G and L genes. NcNSRV-1 is phylogenetically clustered with the unclassified rhabdoviruses isolated from insects and exhibits low sequence identities with other viruses. The transcription regulatory sequences in NcNSRV-1 gene junctions were determined, revealing a unique transcription initiation sequence. In view of the phylogeny, sequence identity and genome organization, NcNSRV-1 is likely to be an insect rhabdovirus. Field surveys showed NcNSRV-1 was prevalent in the rice field populations of N. cincticeps in China.
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A Novel Iflavirus Was Discovered in Green Rice Leafhopper Nephotettix cincticeps and Its Proliferation Was Inhibited by Infection of Rice Dwarf Virus
Frontiers in microbiology, 2021Co-Authors: Wenxi Jia, Fei Wang, Xuefei Chang, Yi Yang, Hongwei Yao, Yanyuan Bao, Qisheng SongAbstract:The green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), is a key insect vector transmitting rice dwarf virus (RDV) that causes rice dwarf disease. We discovered a novel iflavirus from the transcriptomes of N. cincticeps and named it as Nephotettix cincticeps positive-stranded RNA virus-1 (NcPSRV-1). The viral genome consists of 10,524 nucleotides excluding the poly(A) tail and contains one predicted open reading frame encoding a polyprotein of 3,192 amino acids, flanked by 5' and 3' untranslated regions. NcPSRV-1 has a typical iflavirus genome arrangement and is clustered with the members of the family Iflaviridae in the phylogenetic analysis. NcPSRV-1 was detected in all tested tissues and life stages of N. cincticeps and could be transmitted horizontally and vertically. Moreover, NcPSRV-1 had high prevalence in the laboratory populations and was widely spread in field populations of N. cincticeps. NcPSRV-1 could also infect the two-striped leafhopper, Nephotettix apicalis, at a 3.33% infection rate, but was absent in the zigzag leafhopper, Recilia dorsalis, and rice Oryza sativa variety TN1. The infection of RDV altered the viral load and infection rate of NcPSRV-1 in N. cincticeps, for which it seems that RDV has an antagonistic effect on NcPSRV-1 infection in the host.
Fusao Nakasuji - One of the best experts on this subject based on the ideXlab platform.
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Effects of sublethal doses of imidacloprid on the fecundity of green leafhoppers, Nephotettix spp.(Hemiptera:Cicadellidae)and their natural enemies
Applied Entomology and Zoology, 2001Co-Authors: I Nyoman Widiarta, Masaya Matsumura, Yoshito Suzuki, Fusao NakasujiAbstract:Laboratory and field experiments were conducted to examine whether a sublethal dosage application of imidacloprid can induce physiological or ecological resurgence in the green leafhoppers Nephotettix virescens and Nephotettix cincticeps. Fecundity of N. virescens and N. cincticeps exposed to imidacloprid-treated rice seedlings was reduced to one-third and one-half, respectively, that of insects not exposed. Effect of imidacloprid on egg parasitoids of N. virescens was not detected because the percentage parasitism of N. virescens eggs was very low. The number of N. virescens adults consumed by a lycosid spider Pardosa pseudoannulata which was exposed to imidacloprid-treated rice seedlings for the last 24 h before experiment was significantly lower than that on untreated ones. However, the number consumed by a spider fed prey treated directly with imidacloprid was not significantly different from that of untreated prey. Survivorship of the mirid bug Cyrtorhinus lividipennis and the proportions of N. cincticeps eggs preyed on by bugs exposed to imidacloprid-treated seedlings or fed on eggs laid in the stems of treated seedlings were significantly lower than those of untreated ones. The results suggest that a sublethal dosage application of imidacloprid does not cause physiological resurgence in both green leafhopper species but it does induce ecological resurgence.
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Comparison of dispersal ability between the green leafhoppers,Nephotettix virescens andN. cincticeps (hemiptera: Cicadellidae) by tethered flight
Researches on Population Ecology, 1993Co-Authors: I Nyoman Widiarta, Kenji Fujisaki, Tsuyoshi Ikeda, Fusao NakasujiAbstract:Dispersal propensity of green leafhoppers was compared between a tropical species, Nephotettix virescens , and a temperate species, N. cincticeps . The flight ability was measured with tethered flight technique under laboratory conditions (25°C, 16L-8D). The pre-flight period was shorter and the flight duration was longer in N. virescens than in N. cincticeps in both sexes. No significant correlations were found between the flight activity and morphometric characters for either of the two species. The results suggested that dispersal propensity of N. virescens is higher than that of N. cincticeps .
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Life table analysis of the green rice leafhopper,Nephotettix virescens (distant) (Hemiptera: Cicadellidae), and efficient vector of rice tungro disease in asynchronous rice fields in Indonesia
Researches on Population Ecology, 1993Co-Authors: I Gusti Ngurah Aryawan, I Nyoman Widiarta, Yoshito Suzuki, Fusao NakasujiAbstract:Population dynamics of Nephotettix virescens was studied in 17 paddy fields transplanted at intervals of about 1 month in 1988–1990. The adult density was highest either in the immigrant or the 1st generation and sharply decreased to the 2nd generation. The survival rate of the 1st generation was lowest in the transition season when areal population density increased. Key factor analysis revealed that the nymphal and adult mortality of the 1st generation (kn) was the principal source of population fluctuations. No significant correaltion was found between kn and natural enemy density, natural enemy density/healthy egg density, or the precipitation during the nymphal period. On these bases adult emigration was suspected to be the key factor. Areal population build-up of N. virescens in the transition season was considered to occur as a result of increasing immigration to young stages of rice.
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Comparison of dispersal ability between the green leafhoppers, Nephotettix virescens and N. cincticeps (hemiptera: Cicadellidae) by tethered flight
Researches on Population Ecology, 1993Co-Authors: I Nyoman Widiarta, Kenji Fujisaki, Tsuyoshi Ikeda, Fusao NakasujiAbstract:Dispersal propensity of green leafhoppers was compared between a tropical species,Nephotettix virescens, and a temperate species,N. cincticeps. The flight ability was measured with tethered flight technique under laboratory conditions (25°C, 16L-8D). The pre-flight period was shorter and the flight duration was longer inN. virescens than inN. cincticeps in both sexes. No significant correlations were found between the flight activity and morphometric characters for either of the two species. The results suggested that dispersal propensity ofN. virescens is higher than that ofN. cincticeps.