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Oyamada K.,Tochigi Prefectural Agricultural Experiment Station | Oyamada K.,Tochigi Prefectural Sustainable Agriculture Extension Center
Japanese Journal of Applied Entomology and Zoology | Year: 2013

Two spotted spider mites, Tetranychus urticae Koch the most important pests of strawberry, have developed resistance to chemical pesticides. We investigated the effects of high carbon dioxide atmospheres on two-spotted spider mites and strawberry plants just before transplanting. Percent mortality of adult female mites, young eggs(24 h after laying), and old eggs(48-72h) exposed to 60% CO2 at different temperatures(25,30, and 35oC) was evaluated over time. Mortality of all spider mite stages increased with exposure duration at each temperature, and the time required to achieve 100% mortality decreased as temperature increased. Exposure to 60% CO2 at 30oC for 16 h was 100% lethal to every developmental stage tested. Furthermore, 24 h of 60% CO2 treatment did not induce external damage or adversely affect flowering of the primary flower clusters on strawberry plants. In a large-scale test of elevated-CO2 atmospheres, the two spotted spider mite population was greatly suppressed relative to untreated fields, and strawberry plants remained healthy. Thus, our findings suggested that CO2 treatment could be used to propagate spider-mite-free plants in strawberry nurseries and enhance strawberry integrated pest management systems.


Henry C.S.,University of Connecticut | Brooks S.J.,Natural History Museum in London | Johnson J.B.,University of Idaho | Haruyama N.,Tochigi Prefectural Sustainable Agriculture Extension Center | And 2 more authors.
Zootaxa | Year: 2015

Larval morphology and substrate-borne vibrational courtship songs have been hypothesized to distinguish and isolate Chrysoperla 'nipponensis-B' from true 'Type A' Chrysoperla nipponensis (Okamoto), both of which occur sympatrically in eastern Asia. Here, we formally describe C. 'nipponensis-B' as Chrysoperla nigrocapitata sp.n., based on populations sampled throughout Japan and at two sites in South Korea. Behavioral playback experiments show that males and females of each species reject the duetting songs of non-conspecifics, supporting the existence in nature of strong premating reproductive isolation between the two species. Detailed morphological analysis substantiates that the adults of the two species are nearly identical. However, the dorsum of the larval head of C. nigrocapitata is usually darkly and heavily pigmented, in striking contrast to the condition seen in C. nipponensis; if available, it is probably the best trait for distinguishing the two species morphologically. Other aspects of life history, ecology, geographic distribution, and molecular systematics of the new species are briefly considered. Copyright © 2015 Magnolia Press.


Himi E.,Okayama University | Yamashita Y.,Okayama University | Haruyama N.,Tochigi Prefectural Agricultural Experiment Station | Haruyama N.,Tochigi Prefectural Sustainable Agriculture Extension Center | And 3 more authors.
Euphytica | Year: 2012

A number of anthocyanin- and proanthocyanidin-free mutants (ant mutants) in barley were induced and selected because of breeding interest to reduce proanthocyanidins, which could cause haze and degrade the quality of beer. Ant loci, known as anthocyanin or proanthocyanidin synthesis genes, are classified into Ant1 to Ant30 through allelism tests. However, only the Ant18 gene has been molecularly shown to encode dihydroflavonol 4-reductase (DFR), which is involved in both anthocyanin and proanthocyanidin synthesis. In this study, an R2R3 MYB gene of barley was isolated by PCR and named Hvmyb10 due to its similarity to Tamyb10 of wheat, which is a candidate for the R-1 gene grain color regulator. The predicted amino acid sequences of Hvmyb10 showed high similarity not only to Tamyb10 but also to TT2, the proanthocyanidin regulator of Arabidopsis. Non-synonymous nucleotide substitutions in the Hvmyb10 gene were found in all six ant28 mutants tested. Mapping showed that a polymorphism in Hvmyb10 perfectly cosegregated with the ant 28 phenotype on the distal region of the long arm of chromosome 3H. These results demonstrate that ant28 encodes Hvmyb10, the R2R3 MYB domain protein that regulates proanthocyanidin accumulation in developing grains. The reduced grain dormancy of ant28 mutants compared with those of the respective wild types indicates that Hvmyb10 is a key factor in grain dormancy in barley. © 2011 Springer Science+Business Media B.V.


Kubota M.,Japan National Agriculture and Food Research Organization | Morishima M.,Tochigi Prefectural Sustainable Agriculture Extension Center | Iida Y.,Japan National Agriculture and Food Research Organization
Journal of General Plant Pathology | Year: 2015

Tomato cultivar Reiyo, that possesses Cf-9 among other resistance genes but lacks Cf-4, was newly found to be infected with a novel race of the leaf mold pathogen, Passalora fulva after pale to olive mycelia were first observed on chlorotic spots on abaxial leaf surfaces in Tochigi Prefecture, Japan, 2011. In this study, we identified the isolates as races 2.5.9 and 4.5.9. To our knowledge, this is the first report of these races in Japan. © 2015, The Phytopathological Society of Japan and Springer Japan.


PubMed | Natural History Museum in London, University of Connecticut, Swiss Federal Institute of forest, University of Idaho and 2 more.
Type: Journal Article | Journal: Zootaxa | Year: 2015

Larval morphology and substrate-borne vibrational courtship songs have been hypothesized to distinguish and isolate Chrysoperla nipponensis-B from true Type A Chrysoperla nipponensis (Okamoto), both of which occur sympatrically in eastern Asia. Here, we formally describe C. nipponensis-B as Chrysoperla nigrocapitata sp.n., based on populations sampled throughout Japan and at two sites in South Korea. Behavioral playback experiments show that males and females of each species reject the duetting songs of non-conspecifics, supporting the existence in nature of strong premating reproductive isolation between the two species. Detailed morphological analysis substantiates that the adults of the two species are nearly identical. However, the dorsum of the larval head of C. nigrocapitata is usually darkly and heavily pigmented, in striking contrast to the condition seen in C. nipponensis; if available, it is probably the best trait for distinguishing the two species morphologically. Other aspects of life history, ecology, geographic distribution, and molecular systematics of the new species are briefly considered.


Haruyama N.,Tochigi Prefectural Sustainable Agriculture Extension Center | Miyazaki Y.,Chiba University | Nakahira K.,Japan National Institute for Agro - Environmental Sciences | Mochizuki A.,Japan National Institute for Agro - Environmental Sciences | Nomura M.,Chiba University
Annals of the Entomological Society of America | Year: 2012

Because of their importance and abundance as predators of pest insects in agroecosystems around the world, eight species of lacewings from four genera (Apertochrysa, Chrysopa, Chrysoperla, and Dichochrysa) were investigated to evaluate their performance when reared on eggs of Ephestia kuehniella Zeller, a factitious prey commonly used in mass rearing systems. In particular, a comparative assessment of trash-carrying versus naked species (ones not carrying trash on their backs) was performed. We measured the developmental times and survival rates of the eight green lacewings and compared these characteristics between trash-carrying and naked lacewing species. Survival during immature development was higher (7787%) for the two naked species (Chrysopa pallens (Rambur) and Chrysoperla suzukii (Okamoto)) than for the trash-carrying species D. alcestes (33%). Immature and larval developmental times were significantly longer among the trash-carrying species than the naked species. The rapid development of naked green lacewings may be a strategy to decrease predation risk by aphid guarding ants and intra-guild predators. © 2012 Entomological Society of America. © 2012 Entomological Society of America.


Morishima M.,Tochigi Prefectural Agricultural Experiment Station | Morishima M.,Tochigi Prefectural Sustainable Agriculture Extension Center | Fukuda T.,Tochigi Prefectural Agricultural Experiment Station | Fukuda T.,Tochigi Prefectural Sustainable Agriculture Extension Center | Waki T.,Tochigi Prefectural Agricultural Experiment Station
Japanese Journal of Applied Entomology and Zoology | Year: 2012

We investigated the seasonal occurrence of Thrips tabaci (Lindeman), transmitter and viruliferous thrips of Iris yellow spot virus (IYSV), and the incidence of necrotic streak disease caused by IYSV in Chinese chive fields in Tochigi Prefecture, to establish a control system for the disease. The seasonal occurrence of T. tabaci had two peaks. The higher was in mid-June and the other was in mid-August to early September in 2007 and 2008. Transmitter and viruliferous thrips gradually increased from June, peaked between July and October and declined to low levels from December to May. The disease developed after the number of thrips increased, raising the incidence of transmitters and viruliferous individuals in the field. In contrast, symptoms were only observed from July to October and did not develop in new leaves or petioles after cutting plants off above the ground. Moreover, we found viruliferous individuals(1.9%) in the Chinese chive nursery in May 2008, and symptomless infection in the field, based on the detection of IYSV by DAS-ELISA. These results suggested that controlling the population density of thrips in mid-May prevented the development of the disease in Tochigi Prefecture.


Taki H.,Japan Forestry and Forest Products Research Institute | Maeto K.,Kobe University | Okabe K.,Japan Forestry and Forest Products Research Institute | Haruyama N.,Tochigi Prefectural Sustainable Agriculture Extension Center
Agriculture, Ecosystems and Environment | Year: 2013

The biological control of pest insects in farmlands is an important ecosystem service provided by natural enemies, a tenet that is frequently supported by natural ecosystems; however, natural ecosystems can sometimes serve as a source of pests and can maintain them as an ecosystem disservice. We examined the effects of the surrounding seminatural and natural matrix on aphid presence and aphid predator abundance in buckwheat fields. We specifically aimed to detect whether the seminatural and natural matrix causes a trade-off between pest and natural enemy abundances. We established buckwheat study fields in a region of central Japan, the landscape of which is quite complex. Our results showed that aphid presence was not affected by either the abundance of ladybirds and lacewings or the area of the surrounding seminatural and natural matrix. We also found that the abundance of ladybirds, but not of lacewings, was significantly affected by the area of the seminatural and natural matrix. These findings suggest that in a complex landscape, as the area of seminatural and natural lands increases, some assemblages of natural enemies could also increase, but their biological control services would have little effect or would be compensated for by larger pest migration, leading to no net difference in pest damage. © 2013 Elsevier B.V.

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