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Takaaki Daimon - One of the best experts on this subject based on the ideXlab platform.

  • the bombycid moth, Trilocha varians
    2016
    Co-Authors: Takaaki Daimon, Masaya Yagob, Yu-feng Hsuc, Tsuguru Fujiid, Yumiko Nakajimae, Ryuhei Kokushof, Hiroaki Abeg, Susumu Katsumah, Toru Shimadai
    Abstract:

    This study describes the molecular phylogeny, laboratory rearing, and karyotype of a bombycid moth, Trilocha varians (F. Walker) (Lepidoptera: Bombycidae), which feeds on leaves of Ficus spp. (Rosales: Moraceae). The larvae of this species were collected in Taipei city, Taiwan, and the Ryukyu Archipelago (Ishigaki and Okinawa Islands, Japan). Molecular phylogenetic analyses revealed that T. varians belongs to the subfamily Bombycinae, thus showing a close relationship to the domesticated silkworm Bombyx mori (L.), a lepidopteran model insect. A laboratory method was developed for rearing T. varians and the time required for development from the embryo to adult was determined. From oviposition to adult emergence, the developmental zero was 10.47 °C and total effective temperature was 531.2 day–degrees, i.e., approximately 30 days for one generation when reared at 28 °C. The haploid of T. varians consisted of n = 26 chromosomes. In highly polyploid somatic nuclei, females showed a large heterochromatin body, indicating that the sex chromosome system in T. varians is WZ/ZZ (female/male). The results of the present study should facilitate the utilization of T. varians as a reference species for B. mori

  • Flavonoids from the cocoon of Rondotia menciana.
    Phytochemistry, 2013
    Co-Authors: Chikara Hirayama, Toru Shimada, Yan Meng, Takaaki Daimon
    Abstract:

    Abstract Two flavonol glycosides along with four known flavonoids were isolated from the cocoon of the mulberry white caterpillar, Rondotia menciana (Lepidoptera: Bombycidae: Bombycinae), a closely related species of the domesticated silkworm Bombyx mori, both of which feed on leaves of mulberry (Morus alba). The two glycosides were characterized as quercetin 3-O-β- d -galactopyranosyl-(1 → 3)-β- d -galactopyranoside and kaempferol 3-O-β- d -galactopyranosyl-(1 → 3)-β- d -galactopyranoside, based on spectroscopic data and chemical evidence. The flavonol galactosides found in the cocoon were not present in the host plant, nor in the cocoon of the silkworm, B. mori. Notably, flavonol glucosides, which are the main constituents of cocoon flavonoids in B. mori mori, were not found in the R. menciana cocoon. The present result strongly suggests that R. menciana is quite unique in that they predominantly use an UDP-galactosyltransferase for conjugation of dietary flavonoids, whereas UDP-glucosyltransferases are generally used for conjugation of plant phenolics and xenobiotics in other insects.

  • Reinvestigation of the Sex Pheromone of the Wild Silkmoth Bombyx mandarina: The Effects of Bombykal and Bombykyl Acetate
    Journal of Chemical Ecology, 2012
    Co-Authors: Takaaki Daimon, Tsuguru Fujii, Susumu Katsuma, Toru Shimada, Takeshi Fujii, Takeshi Yokoyama, Tetsuro Shinoda, Yukio Ishikawa
    Abstract:

    Sex pheromone investigations of the domesticated silkmoth, Bombyx mori (Lepidoptera: Bombycidae), helped elucidate the molecular and physiological fundamentals of chemical communication in moths, yet little is known about pheromone evolution in bombycid species. Therefore, we reexamined the sex pheromone communication in the wild silkmoth, Bombyx mandarina , which is considered ancestral to B. mori . Our investigations revealed that (a) B. mandarina females produce ( E,Z )-10,12-hexadecadienol (bombykol), but not ( E,Z )-10,12-hexadecadienal (bombykal) or ( E,Z )-10,12-hexadecadienyl acetate (bombykyl acetate), which are pheromone components in other bombycid moths; (b) antennae of male B. mandarina respond strongly to bombykol as well as to bombykal and bombykyl acetate; and (c) bombykal and bombykyl acetate strongly inhibit attraction of B. mandarina males to bombykol in the field. The present study clarifies the evolution of pheromone communication in bombycid moths.

Toru Shimada - One of the best experts on this subject based on the ideXlab platform.

  • Identification and functional analysis of a Masculinizer orthologue in Trilocha varians (Lepidoptera: Bombycidae).
    Insect molecular biology, 2015
    Co-Authors: Jung Lee, Toru Shimada, Takashi Kiuchi, Munetaka Kawamoto, Susumu Katsuma
    Abstract:

    We recently showed that the Masculinizer gene (Masc) plays a primary role in sex determination in the lepidopteran model insect Bombyx mori. However, it remains unknown whether this Masc protein-dependent sex determination system is conserved amongst lepidopteran insects or within the family Bombycidae. Here we cloned and characterized a Masc homologue (TvMasc) in Trilocha varians (Lepidoptera: Bombycidae), a species closely related to B. mori. To elucidate the role of TvMasc in the sex determination cascade of T. varians, TvMasc expression was knocked down in early embryos by the injection of small interfering RNAs (siRNAs) that targeted TvMasc mRNAs. Both female- and male-type splice variants of Tvdsx, a doublesex (dsx) homologue in T. varians were observed in control siRNA-injected embryos. By contrast, only female-type splice variants were observed in TvMasc siRNA-injected embryos. These results indicate that the TvMasc protein directly or indirectly regulates the splicing patterns of Tvdsx. Furthermore, we found that male-type splice variants of B. mori dsx (Bmdsx) were produced in TvMasc-overexpressing BmN4 cells. The mRNA level of B. mori Imp, a gene whose product induces male-specific Bmdsx splicing also increased. These results suggest that Masc genes play similar roles in the sex-determination cascade in Bombycidae.

  • Flavonoids from the cocoon of Rondotia menciana.
    Phytochemistry, 2013
    Co-Authors: Chikara Hirayama, Toru Shimada, Yan Meng, Takaaki Daimon
    Abstract:

    Abstract Two flavonol glycosides along with four known flavonoids were isolated from the cocoon of the mulberry white caterpillar, Rondotia menciana (Lepidoptera: Bombycidae: Bombycinae), a closely related species of the domesticated silkworm Bombyx mori, both of which feed on leaves of mulberry (Morus alba). The two glycosides were characterized as quercetin 3-O-β- d -galactopyranosyl-(1 → 3)-β- d -galactopyranoside and kaempferol 3-O-β- d -galactopyranosyl-(1 → 3)-β- d -galactopyranoside, based on spectroscopic data and chemical evidence. The flavonol galactosides found in the cocoon were not present in the host plant, nor in the cocoon of the silkworm, B. mori. Notably, flavonol glucosides, which are the main constituents of cocoon flavonoids in B. mori mori, were not found in the R. menciana cocoon. The present result strongly suggests that R. menciana is quite unique in that they predominantly use an UDP-galactosyltransferase for conjugation of dietary flavonoids, whereas UDP-glucosyltransferases are generally used for conjugation of plant phenolics and xenobiotics in other insects.

  • Reinvestigation of the Sex Pheromone of the Wild Silkmoth Bombyx mandarina: The Effects of Bombykal and Bombykyl Acetate
    Journal of Chemical Ecology, 2012
    Co-Authors: Takaaki Daimon, Tsuguru Fujii, Susumu Katsuma, Toru Shimada, Takeshi Fujii, Takeshi Yokoyama, Tetsuro Shinoda, Yukio Ishikawa
    Abstract:

    Sex pheromone investigations of the domesticated silkmoth, Bombyx mori (Lepidoptera: Bombycidae), helped elucidate the molecular and physiological fundamentals of chemical communication in moths, yet little is known about pheromone evolution in bombycid species. Therefore, we reexamined the sex pheromone communication in the wild silkmoth, Bombyx mandarina , which is considered ancestral to B. mori . Our investigations revealed that (a) B. mandarina females produce ( E,Z )-10,12-hexadecadienol (bombykol), but not ( E,Z )-10,12-hexadecadienal (bombykal) or ( E,Z )-10,12-hexadecadienyl acetate (bombykyl acetate), which are pheromone components in other bombycid moths; (b) antennae of male B. mandarina respond strongly to bombykol as well as to bombykal and bombykyl acetate; and (c) bombykal and bombykyl acetate strongly inhibit attraction of B. mandarina males to bombykol in the field. The present study clarifies the evolution of pheromone communication in bombycid moths.

  • Phylogenetic Relationship of Silkmoths Inferred from Sequence Data of the Arylphorin Gene
    Molecular phylogenetics and evolution, 1995
    Co-Authors: Toru Shimada, Y. Kurimoto, M. Kobayashi
    Abstract:

    A portion of the arylphorin gene from 11 silkmoth species belonging to the families Saturniidae and Bombycidae was amplified by a polymerase chain reaction. Approximately 460 bp corresponding to the third exon, the third intron, and the fourth exon were successfully amplified, sequenced, and compared. Sequences corresponding to the third and fourth exons were the most conserved, whereas sequences corresponding to the third intron were conserved only between species belonging to the same genus. We also analyzed differences of substitution rates among codon positions and between synonymous and nonsynonymous sites. Phylogenetic trees were constructed using the entire nucleotide sequences, the first and second codon positions, nonsynonymous sites, transversions, and the inferred amino acid sequences in the exons by the neighbor-joining method. These trees supported the monophyly of the families Saturniidae and Bombycidae as well as the monophyly of the genera Actias, Bombyx, Antheraea, and Samia.

Susumu Katsuma - One of the best experts on this subject based on the ideXlab platform.

  • Identification and functional analysis of a Masculinizer orthologue in Trilocha varians (Lepidoptera: Bombycidae).
    Insect molecular biology, 2015
    Co-Authors: Jung Lee, Toru Shimada, Takashi Kiuchi, Munetaka Kawamoto, Susumu Katsuma
    Abstract:

    We recently showed that the Masculinizer gene (Masc) plays a primary role in sex determination in the lepidopteran model insect Bombyx mori. However, it remains unknown whether this Masc protein-dependent sex determination system is conserved amongst lepidopteran insects or within the family Bombycidae. Here we cloned and characterized a Masc homologue (TvMasc) in Trilocha varians (Lepidoptera: Bombycidae), a species closely related to B. mori. To elucidate the role of TvMasc in the sex determination cascade of T. varians, TvMasc expression was knocked down in early embryos by the injection of small interfering RNAs (siRNAs) that targeted TvMasc mRNAs. Both female- and male-type splice variants of Tvdsx, a doublesex (dsx) homologue in T. varians were observed in control siRNA-injected embryos. By contrast, only female-type splice variants were observed in TvMasc siRNA-injected embryos. These results indicate that the TvMasc protein directly or indirectly regulates the splicing patterns of Tvdsx. Furthermore, we found that male-type splice variants of B. mori dsx (Bmdsx) were produced in TvMasc-overexpressing BmN4 cells. The mRNA level of B. mori Imp, a gene whose product induces male-specific Bmdsx splicing also increased. These results suggest that Masc genes play similar roles in the sex-determination cascade in Bombycidae.

  • Reinvestigation of the Sex Pheromone of the Wild Silkmoth Bombyx mandarina: The Effects of Bombykal and Bombykyl Acetate
    Journal of Chemical Ecology, 2012
    Co-Authors: Takaaki Daimon, Tsuguru Fujii, Susumu Katsuma, Toru Shimada, Takeshi Fujii, Takeshi Yokoyama, Tetsuro Shinoda, Yukio Ishikawa
    Abstract:

    Sex pheromone investigations of the domesticated silkmoth, Bombyx mori (Lepidoptera: Bombycidae), helped elucidate the molecular and physiological fundamentals of chemical communication in moths, yet little is known about pheromone evolution in bombycid species. Therefore, we reexamined the sex pheromone communication in the wild silkmoth, Bombyx mandarina , which is considered ancestral to B. mori . Our investigations revealed that (a) B. mandarina females produce ( E,Z )-10,12-hexadecadienol (bombykol), but not ( E,Z )-10,12-hexadecadienal (bombykal) or ( E,Z )-10,12-hexadecadienyl acetate (bombykyl acetate), which are pheromone components in other bombycid moths; (b) antennae of male B. mandarina respond strongly to bombykol as well as to bombykal and bombykyl acetate; and (c) bombykal and bombykyl acetate strongly inhibit attraction of B. mandarina males to bombykol in the field. The present study clarifies the evolution of pheromone communication in bombycid moths.

Ataur Rahman Khan - One of the best experts on this subject based on the ideXlab platform.

  • Effect of UV Radiation on the Uzi-Fly, Exorista sorbillans Wiedemann, an Endoparasitoid of the Silkworm, Bombyx mori L.
    International Journal of Tropical Insect Science, 1998
    Co-Authors: Mahbub Hasan, M. Sarwar Jahan, Ataur Rahman Khan
    Abstract:

    In laboratory experiments, pupae of the uzi fly, Exorista sorbillans Wiedemann (Diptera: Tachinidae), an endoparasitoid of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae) were subjected to UV-irradiation for different durations. Upon adult emergence, irradiated and control flies were crossed in all possible combinations and allowed to parasitise healthy silkworms. Adult emergence, fecundity and longevity of the resulting progeny were recorded. Progeny of irradiated E. sorbillans showed significantly reduced adult emergence, oviposition period and hatchability. The reduction in fecundity was negatively correlated with the duration of exposure to UV radiation. The longevity of uzi flies of both the sexes was also significantly reduced. Au cours des essais en laboratoire, des pupes de la mouche Exorista sorbillans (Diptera: Tachinidae), un endoparasitoïde du ver à soie, Bombyx mori L. (Lepidoptera: Bombycidae), ont été soumises à une irradiation aux rayons ultra-violets (UV) pour des durées différentes d’exposition. A leur émergence, les adultes des mouches irradiées et ceux du témoin étaient croisés par toutes les combinaisons possibles, puis laissés parasiter les vers à soie bien portants. On a pris note du taux d’émergence des adultes, de la fécondité et de la longévité des descendants issus des croisements. Il a été constaté que les descendants nés des sujets irradiés de E. sorbillans montraient une réduction significative du taux d’émergence des adultes, de la durée de ponte et du taux d’éclosion d’oeufs. La réduction de fécondité était négativement corrélée avec la durée d’irradiation aux rayons ultra-violets. La longévité était aussi significativement réduite chez les deux sexes.

  • effect of uv radiation on the uzi fly exorista sorbillans wiedemann an endoparasitoid of the silkworm bombyx mori l
    International Journal of Tropical Insect Science, 1998
    Co-Authors: Mahbub Hasan, Sarwar M Jahan, Ataur Rahman Khan
    Abstract:

    In laboratory experiments, pupae of the uzi fly, Exorista sorbillans Wiedemann (Diptera: Tachinidae), an endoparasitoid of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae) were subjected to UV-irradiation for different durations. Upon adult emergence, irradiated and control flies were crossed in all possible combinations and allowed to parasitise healthy silkworms. Adult emergence, fecundity and longevity of the resulting progeny were recorded. Progeny of irradiated E. sorbillans showed significantly reduced adult emergence, oviposition period and hatchability. The reduction in fecundity was negatively correlated with the duration of exposure to UV radiation. The longevity of uzi flies of both the sexes was also significantly reduced.

M. V. Navasero - One of the best experts on this subject based on the ideXlab platform.

  • OCCURRENCE OF THE MORACEAE-FEEDING BOMBYCID, Trilocha varians (Walker) (Bombycidae, LEPIDOPTERA) AS PEST OF JACKFRUIT AND SOME ORNAMENTAL SPECIES OF FICUS IN THE PHILIPPINES
    Journal of International Society for Southeast Asian Agricultural Sciences, 2013
    Co-Authors: M. V. Navasero, M. C. Dl. De Roxas, S. M. F. Calumpang
    Abstract:

    The occurrence of the bombycid moth, Trilocha varians (Walker) (Lepidoptera: Bombycidae) was observed and monitored among Ficus benjamina and F. nitida in the landscape of the National Crop Protection Center from August to December 2012. Eggs, larvae and pupae of the pest were all present on the infested shrubs. The larvae completely defoliated and eventually killed some of the Ficus plants . At the peak of infestation, larvae can consume all of the leaves of an individual shrub in just overnight. T. varians was also observed infesting jackfruit in Los Banos, Laguna and Balete, Batangas as well as on F. nitida in Baguio City . The nature of damage, host response and host range were discussed. This is the first record of T. varians as pest of Artocarpus heterpphyllus, A. communis , A. kamansi and some ornamental species of Ficu s in the Philippines.

  • OCCURRENCE OF THE MORACEAE-FEEDING BOMBYCID, Trilocha varians (Walker) (Bombycidae, LEPIDOPTERA) AS PEST OF JACKFRUIT AND SOME ORNAMENTAL SPECIES OF FICUS IN THE PHILIPPINES
    2013
    Co-Authors: M. V. Navasero, M. C. Dl. De Roxas, Susan May, F. Calumpang
    Abstract:

    The occurrence of the bombycid moth, Trilocha varians (Walker) (Lepidoptera: Bombycidae) was observed and monitored among Ficus benjamina and F. nitida in the landscape of the National Crop Protection Center from August to December 2012. Eggs, larvae and pupae of the pest were all present on the infested shrubs. The larvae completely defoliated and eventually killed some of the Ficus plants. At the peak of infestation, larvae can consume all of the leaves of an individual shrub in just overnight. T. varians was also observed infesting jackfruit in Los Baños, Laguna and Balete, Batangas as well as on F. nitida in Baguio City. The nature of damage, host response and host range were discussed. This is the first record of T. varians as pest of Artocarpus heterpphyllus, A. communis, A. kamansi and some ornamental species of Ficus in the Philippines. Key words: damage, host range, invasive pes