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ABSTRACT: BACKGROUND: The brown planthopper Nilaparvata lugens and the whitebacked planthopper Sogatella furcifera are both important pests on rice throughout Asia. The major cause of recent outbreaks is thought to be the development of insecticide resistance. Thus, we monitored insecticide susceptibilities in populations of these two insects immigrating into Japan in the period 2005-2012. We tested ten insecticides, including members of the organophosphate, carbamate, pyrethroid, neonicotinoid, and phenylpyrazole groups. RESULTS: The LD50 values of N. lugens against imidacloprid increased from 2005 (0.7 µg g(-1) ) to 2012 (98.5 µg g(-1) ). The resistance ratio (LD50 value in 2012 / baseline LD50 value in 1992) was 615.5. In contrast, LD50 values of N. lugens against fipronil were <1.0 µg g(-1) through 2012, suggesting that N. lugens had developed no insecticide resistance to this insecticide. However, S. furcifera exhibited resistance against fipronil through 2012. Except in the case of malathion the resistances of N. lugens against members of the organophosphate and carbamate groups were closely similar in the period 2005-2012 to earlier determinations in 1984 and 1985. CONCLUSION: Species-specific insecticide resistance (imidacloprid resistance in N. lugens and fipronil resistance in S. furcifera) is ongoing in populations of two planthoppers immigrating into Japan.
Pest Management Science 06/2013; · 2.25 Impact Factor
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ABSTRACT: The brown planthoppers (BPH) Nilaparvata lugens (Stål) and the white-backed planthoppers (WBPH) Sogatella furcifera (Horváth) annually migrate from tropical and subtropical regions to temperate regions in Asia, including Japan, Korea and northern China. To elucidate the genetic divergence based on geography of planthoppers and to estimate their migration route on the basis of molecular data, we analysed a part of their mitochondrial genome sequences. Sequences of cytochrome oxidase subunit I (cox1) - transfer RNA for Leu (trnL2) - cox2 were determined for 579 BPH (1,928 bp) and 464 WBPH (1,927 bp) individuals collected from 31 and 25 locations, respectively, in East and Southeast Asia. Thirty and 20 mitochondrial haplotypes were detected for BPH and WBPH, respectively. Single populations of both planthoppers included multiple haplotypes, and many haplotypes were shared in some populations and areas. The most frequently detected haplotypes accounted for approximately 50% of all BPH and WBPH individuals. To evaluate gene flow among planthoppers in different regions in Asia, pairwise fixation index (Fst) values were calculated. For BPH, high Fst values (0.580-0.926) were shown between planthoppers in Papua New Guinea (PNG) and the other areas and moderate Fst values (0.176-0.362) were observed between those in southern Philippines and other areas. For WBPH, the Fst value was the highest between Taiwan and southern Vietnam (0.236), and low among the other areas. AMOVA indicated no genetic structure among eight areas, excluding southern Philippines and PNG, for BPH, and among ten areas for WBPH. These data indicate that both planthoppers do not show much differentiation of local populations and/or have genetically intermixed Asian populations. These data also indicate that it may be difficult to distinguish regional planthopper populations on the basis of differences in mitochondrial sequences.
Bulletin of entomological research 03/2013; · 1.58 Impact Factor
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ABSTRACT: The maize orange leafhopper Cicadulina bipunctata (Hemiptera: Cicadellidae) induces galls characterized by growth stunting and severe swelling of leaf veins on various plants of Poaceae. Previous studies revealed that galls are induced not on feeding site but on distant, newly extended leaves during the feeding, and strongly suggested that some chemicals injected by the leafhopper affect at the leaf primordia. To approach the mechanism underlying gall induction by C. bipunctata, we examined physiological response of plants to feeding by the leafhopper. We performed high-throughput and comprehensive plant hormone analyses using LC-ESI-MS/MS. Galled maize leaves contained higher contents of abscisic acid (ABA) and trans-Zeatin (tZ) and lower contents of gibberellins (GA1 and GA4) than ungalled maize leaves. Leafhopper treatment significantly increased ABA and tZ contents and decreased GA1 and GA4 contents in extending leaves. After the removal of leafhoppers, contents of tZ and gibberellins in extending leaves soon became similar to the control values. ABA content was gradually decreased after the removal of leafhoppers. Such hormonal changes were not observed in leafhopper treatment on leaves of resistant maize variety. Water contents of galled leaves were significantly lower than control leaves, suggesting water stress of galled leaves and possible reason of the increase in ABA content. These results imply that ABA, tZ, and gibberellins are related to gall induction by the leafhopper on susceptible variety of maize.
PLoS ONE 01/2013; 8(4):e62350. · 4.09 Impact Factor
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ABSTRACT: AbstractThe pattern of overseas immigration of Laodelphax
striatellus (Fallén) into northern Kyushu district in relation to weather conditions was analyzed using trap catch data, weather data,
and backward trajectory analysis. The investigation covered the period May 21 to June 10 of each year between 2000 and 2009.
One peak trap catch was recorded on May 27–28, 2006 and was associated with strong westerly winds at 850 and 925hPa levels
to the south of a cold vortex that passed over the southern part of the Korean peninsula. The backward trajectory analysis
suggested Jiangsu Province, China, as possible migration source. Another peak catch on June 5, 2008 has already been reported
as an overseas migration from Jiangsu Province, China. This study revealed that a cold vortex passing the southern Korean
peninsula was also associated with insect migration in 2008. Thus, there is evidence of at least 2 overseas migrations from
Jiangsu Province, China, over a 10-year period that coincided with strong westerly winds in the lower atmosphere that were
associated with cold vortices.
Keywords
Laodelphax striatellus
–Long-distance migration–Weather conditions–Cold vortex–Backward trajectory analysis
Applied Entomology and Zoology 04/2012; 46(1):41-50. · 1.14 Impact Factor
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ABSTRACT: The twisted-wing parasite Elenchus japonicus is a major parasitoid of rice planthoppers (Hemiptera: Delphacidae), including the brown planthopper Nilaparvata lugens, the white-backed planthopper Sogatella furcifera, and the small brown planthopper Laodelphax striatellus. Another Elenchus species, E. yasumatsui, which is considered to be synonymous with E. japonicus, has also been described in southern Asia. However, limited biological and molecular data on this important parasitoid of
rice planthoppers are available. In this study, E. japonicas-stylopized planthoppers were obtained from various regions in Asia and Japan. Sequences of the nuclear 18S ribosomal RNA
gene and the mitochondrial cytochrome oxidase I gene of the strepsipterans were analyzed from 40 samples of E. japonicus: 14 from N. lugens, 6 from S. furcifera and 20 from L. striatellus. Sequence analysis of these samples revealed three genotypes of E. japonicus. Of the three types of E. japonicus, one was isolated only from L. striatellus from northern Japan. The other two types were found in all three rice planthopper species collected from a wide area in Asia.
These results suggest that the three different genotypes of Elenchus can be associated with a particular geographical region and/or planthopper species. The relationship between two previously
described Elenchus species and the present three genotypes needs to be elucidated.
Keywords
Elenchus japonicus
–Strepsiptera–rRNA gene–
cox1
–Planthopper
Applied Entomology and Zoology 04/2012; 46(3):435-442. · 1.14 Impact Factor
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ABSTRACT: The small brown planthopper, Laodelphax striatellus, is one of the most serious pest insects of rice plants. A large migration of the insects from overseas was reported in western
parts of Japan in June 2008. Insecticide resistance to imidacloprid, fipronil and BPMC was compared among local populations
in these western regions after migration. The insecticides were applied to the insects using a topical application method.
In some populations, the resistance status coincided with that of the immigrant insects just after migration, i.e., resistance
to imidacloprid but susceptibility to fipronil. In other populations, resistance was observed not only against imidacloprid
but also fipronil. It is likely that the status of the latter populations resulted from intercrossing between domestic populations
of the insects and migrants. Insecticide resistance was also assessed in other areas of northern and eastern parts of Japan.
In general, these populations showed relatively low resistance, although resistance to fipronil was high in the eastern part
of Japan where the density of domestic populations has recently increased. Insecticide susceptibilities were also assessed
in several sites in Taiwan and the northern parts of Vietnam. Although susceptibilities differed among these sites or countries,
they have recently seen a decline for all three insecticides.
KeywordsImidacloprid–Fipronil–BPMC–Long-distance migration–Topical application
Applied Entomology and Zoology 04/2012; 46(1):65-73. · 1.14 Impact Factor
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03/2012; , ISBN: 978-953-51-0454-4
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ABSTRACT: Particular alkaloids produced by Neotyphodium endophytes show toxicity to invertebrates. Italian ryegrass (Lolium multiflorum Lamarck) cultivars and strains that are symbiotic with Neotyphodium endophytes have been recently established in Japan. N. uncinatum-infected Italian ryegrass lines accumulate N-formylloline, a type of loline alkaloid (1-aminopyrrolizidine) showing neurotoxicity to herbivorous insects. This study investigated the toxicity of N-formylloline and resistance of N. uncinatum-infected Italian ryegrass to vascular-sap feeding Clypeorrhynchan pests. When four vascular-sap feeding insects: Laodelphax striatellus (Fallén) (Homoptera: Delphacidae), Sogatella furcifera (Horváth) (Homoptera: Delphacidae), Cicadulina bipunctata (Melichar) (Homoptera: Cicadellidae), and Nephotettix cincticeps (Uhler) (Homoptera: Cicadellidae) fed on N. uncinatum-infected Italian ryegrass, significant decreases in survival rate were observed for three phloem-sap feeders but not for a xylem-sap feeder, N. cincticeps. This result suggests an uneven distribution of N-formylloline among plant tissues. A potency assay for N-formylloline using a Parafilm feeding sachet and a quantitative analysis of N-formylloline in plant showed a concentration-dependent lethal effect of N-formylloline on all four tested vascular-sap feeders. Our results strongly suggest that N. uncinatum-infected plants can control some Clypeorrhynchan pests in crop fields.
Journal of Economic Entomology 02/2012; 105(1):129-34. · 1.70 Impact Factor
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ABSTRACT: The brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most serious and destructive pests of rice, and can be found throughout the rice-growing areas of Asia. To date, more than 24 major BPH-resistance genes have been reported in several Oryza sativa ssp. indica cultivars and wild relatives. Here, we report the genetic basis of the high level of BPH resistance derived from an Indian rice cultivar, ADR52, which was previously identified as resistant to the whitebacked planthopper (Sogatella furcifera [Horváth]). An F(2) population derived from a cross between ADR52 and a susceptible cultivar, Taichung 65 (T65), was used for quantitative trait locus (QTL) analysis. Antibiosis testing showed that multiple loci controlled the high level of BPH resistance in this F(2) population. Further linkage analysis using backcross populations resulted in the identification of BPH-resistance (antibiosis) gene loci from ADR52. BPH25 co-segregated with marker S00310 on the distal end of the short arm of chromosome 6, and BPH26 co-segregated with marker RM5479 on the long arm of chromosome 12. To characterize the virulence of the most recently migrated BPH strain in Japan, preliminary near-isogenic lines (pre-NILs) and a preliminary pyramided line (pre-PYL) carrying BPH25 and BPH26 were evaluated. Although both pre-NILs were susceptible to the virulent BPH strain, the pre-PYL exhibited a high level of resistance. The pyramiding of resistance genes is therefore likely to be effective for increasing the durability of resistance against the new virulent BPH strain in Japan.
Theoretical and Applied Genetics 11/2011; 124(3):495-504. · 3.30 Impact Factor
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ABSTRACT: The maize orange leafhopper Cicadulina bipunctata is distributed widely in tropical and subtropical regions of the Old World and feeds on various Poaceae. The leafhopper is recognized as an important pest of maize in several countries. Adults as well as nymphs of C. bipunctata induce growth stunting and galls characterized by the severe swelling of leaf veins on many cereal crops including wheat, rice, and maize, but do not on barley. To clarify the mechanism of growth stunting and gall induction by C. bipunctata, we used six barley chromosome disomic addition lines of wheat (2H-7H) and investigated the effect of barley (cv. Betzes) chromosome addition on the susceptibility of wheat (cv. Chinese Spring) to feeding by the leafhopper. Feeding by C. bipunctata significantly stunted the growth in 2H, 3H, 4H, and 5H, but did not in 6H and 7H. The degree of gall induction was significantly weaker and severer in 3H and 5H than in Chinese Spring, respectively. These results suggest that barley genes resistant to growth stunting and gall induction exist in 6H and 7H, and 3H, respectively. 5H is considered to be useful for future assays investigating the mechanism of gall induction by this leafhopper because of the high susceptibility to the feeding by C. bipunctata. Significant correlation between the degrees of growth stunting and gall induction was not detected in the six chromosome addition lines and Chinese spring. This implies that these two symptoms are independent phenomena although both are initiated by the feeding of C. bipunctata.
Naturwissenschaften 09/2011; 98(11):983-7. · 2.28 Impact Factor
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ABSTRACT: The maize orange leafhopper, Cicadulina bipunctata, is a multivoltine insect that induces galls on various plants of the Poaceae. A previous study revealed that galls produced by this leafhopper were induced by dose-dependent stimulation on distant leaves from the feeding site, probably by chemical(s) injected from adults during feeding. In this paper, we examined the gall-inducing ability of C. bipunctata nymphs. The degree of gall induction gradually increased depending on the number of feeding nymphs and there were no significant differences from the positive control (feeding by five male adults) when seedlings were exposed to five or more nymphs. These results indicate that both adults and nymphs of C. bipunctata have the ability to induce galls on their host plants, a unique feature among gallinducing insects. This feature may be related to the free-living, multivoltine and polyphagous habits of C. bipunctata.
Communicative & integrative biology 07/2010; 3(4):388-9.
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Kenji Gomi,
Masaru Satoh,
Rika Ozawa,
Yumi Shinonaga,
Sachiyo Sanada,
Katsutomo Sasaki, Masaya Matsumura,
Yuko Ohashi,
Hiroo Kanno,
Kazuya Akimitsu,
Junji Takabayashi
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ABSTRACT: A pre-infestation of the white-backed planthopper (WBPH), Sogatella furcifera Horváth, conferred resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) in rice (Oryza sativa L.) under both laboratory and field conditions. The infestation of another planthopper species, the brown planthopper (BPH) Nilaparvata lugens Stål, did not significantly reduce the incidence of bacterial blight symptoms. A large-scale screening using a rice DNA microarray and quantitative RT-PCR revealed that WBPH infestation caused the upregulation of more defence-related genes than did BPH infestation. Hydroperoxide lyase 2 (OsHPL2), an enzyme for producing C(6) volatiles, was upregulated by WBPH infestation, but not by BPH infestation. One C(6) volatile, (E)-2-hexenal, accumulated in rice after WBPH infestation, but not after BPH infestation. A direct application of (E)-2-hexenal to a liquid culture of Xoo inhibited the growth of the bacterium. Furthermore, a vapour treatment of rice plants with (E)-2-hexenal induced resistance to bacterial blight. OsHPL2-overexpressing transgenic rice plants exhibited increased resistance to bacterial blight. Based on these data, we conclude that OsHPL2 and its derived (E)-2-hexenal play some role in WBPH-induced resistance in rice.
The Plant Journal 09/2009; 61(1):46-57. · 6.16 Impact Factor
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ABSTRACT: The evolution of the gall-inducing ability in insects and the adaptive significance of the galling habit have been addressed by many studies. Cicadulina bipunctata, the maize orange leafhopper, is an ideal study organism for evaluating these topics because it can be mass-reared and it feeds on model plants such as rice (Oryza sativa) and maize (Zea mays). To reveal differences between gall inductions by C. bipunctata and other gall inducers, we conducted four experiments concerning (a) the relationship between the feeding site and gall-induction sites of C. bipunctata on maize, (b) the effects of leafhopper sex and density, (c) the effects of length of infestation on gall induction, and (d) the effects of continuous infestation. C. bipunctata did not induce galls on the leaves where it fed but induced galls on other leaves situated at more distal positions. The degree of gall induction was significantly correlated with infestation density and length. These results indicate that C. bipunctata induces galls in a dose-dependent manner on leaves distant from feeding sites, probably by injecting chemical(s) to the plant during feeding. We suggest that insect galls are induced by a chemical stimulus injected by gall inducers during feeding into the hosts.
Naturwissenschaften 07/2009; 96(9):1059-66. · 2.28 Impact Factor
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Applied Entomology and Zoology - APPL ENTOMOL ZOOL. 01/2009; 44(1):149-153.
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Applied Entomology and Zoology - APPL ENTOMOL ZOOL. 01/2009; 44(2):207-214.
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ABSTRACT: In 2003 the development of insecticide resistance against neonicotinoids in the brown planthopper (BPH), Nilaparvata lugens (Stål) (Homoptera: Delphacidae), was first observed in Thailand and has since been found in other Asian countries such as Vietnam, China and Japan. However, the LD(50) values of BPH and the whitebacked planthopper (WBPH), Sogatella furcifera (Horváth), against both neonicotinoid and phenylpyrazole insecticides have been poorly reported in many Asian countries.
The topical LD(50) values for imidacloprid in the BPH populations collected from East Asia (Japan, China, Taiwan) and Vietnam in 2006 were 4.3-24.2 microg g(-1) and were significantly higher than those collected from the Philippines (0.18-0.35 microg g(-1)). The BPH populations indicated a positive cross-resistance between imidacloprid and thiamethoxam. Almost all the WBPH populations from Japan, Taiwan, China, Vietnam and the Philippines had extremely large LD(50) values (19.7-239 microg g(-1) or more) for fipronil, except for several populations from the Philippines and China.
Species-specific changes in insecticide susceptibility were found in Asian rice planthoppers (i.e. BPH for imidacloprid and WBPH for fipronil). Insecticide resistance in BPH against imidacloprid occurred in East Asia and Indochina, but not in the Philippines. In contrast, insecticide resistance in WBPH against fipronil occurred widely in East and South-east Asia.
Pest Management Science 10/2008; 64(11):1115-21. · 2.25 Impact Factor
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ABSTRACT: The maize orange leafhopper Cicadulina bipunctata is distributed widely from Africa to Asia including Japan, and northern Australia. Some cereals infested by C. bipunctata, such as maize and rice, exhibit stunted growth and severe swelling of leaf veins, symptoms commonly referred to as ‘wallaby
ear disease’. Though previous studies attributed the symptoms to a leafhopper-transmitted virus, recent studies suggest that
chemicals injected by C. bipunctata during feeding are important contributors to these symptoms. Therefore the damage is considered a sort of insect gall. Following
the initiation of biyearly plantings of forage maize in Kyushu, Japan, C. bipunctata became recognized as a serious insect pest of forage maize. Since 2001 the total area of forage maize fields damaged by C. bipunctata has gradually increased, and outbreaks of C. bipunctata occurred in 2004. We speculate that relatively low winter mortality and early appearance of C. bipunctata are possible factors contributing to re-cent outbreaks. In central Kyushu, an increase of 1.3 generations per year following
global warming is estimated for C. bipunctata by 2100, relative to 1990. Thus, C. bipunctata has the potential to become a serious insect pest of cereal crops other than forage maize in the future.
12/2005: pages 149-158;
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ABSTRACT: Migrations of the rice planthopper Nilaparvata lugens (Stl) (Delphacidae) from the Philippines to Taiwan, southern China, and southern Japan were analyzed using three-dimensional migration simulations. The results strongly suggested that the Southeast Asian population of N. lugens mixes with the East Asian population. This highlighted the possibility that planthoppers from the Southeast Asian population, which have properties different from those in the East Asian population such as feeding of resistant rice varieties and wing polymorphism, could migrate to Japan via southern China and Taiwan. This study, therefore, emphasizes the special care that should be taken to monitor the properties of immigrants to Japan.
Population Ecology 07/2005; 47(2):143-150. · 2.29 Impact Factor
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ABSTRACT: 1. A series of laboratory experiments was conducted to explore the effects of inter-specific interactions, both direct interactive effects and those induced through previous feeding, on the dispersal capability (proportion of macropterous adults) and performance (development time and survival) of two wing-dimorphic planthoppers, the whitebacked planthopper Sogatella furcifera and the brown planthopper Nilaparvata lugens, two pests of rice throughout Asia.2. An asymmetric effect of inter-specific crowding on dispersal capability was detected between the two planthoppers. With density controlled, the proportion of macropterous adults in N. lugens was higher when raised in mixed populations with S. furcifera than in pure cultures comprised of conspecifics, suggesting that interspecific effects on dispersal capability are stronger than intraspecific effects. In contrast, interspecific effects on macroptery (%) were weaker than intraspecific impacts for S. furcifera.3. This trend was parallelled by adverse competitive effects on survival, with interspecific effects stronger than intraspecific impacts for N. lugens and intraspecific effects stronger for S. furcifera.4. Crowding also affected the incidence of macroptery indirectly through feeding-induced changes in plant physiology. Rearing N. lugens on plants fed on previously by heterospecifics resulted in a higher incidence of macroptery in females and protracted development than for N. lugens raised on plants fed on previously by conspecifics. By contrast, the intraspecific effect of previous feeding was stronger than the interspecific effect in S. furcifera, with higher macropter production and prolonged development occurring on plants exposed previously to conspecifics.5. The results suggest that interspecific interactions between herbivorous insects, both direct and via feeding-induced changes in plant physiology, can have negative consequences for performance and survival and promote the production of flight-capable adults that can disperse.
Ecological Entomology 03/2003; 28(2):174 - 182. · 2.00 Impact Factor
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