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Coby Schal - One of the best experts on this subject based on the ideXlab platform.

  • diet quality affects bait performance in german cockroaches dictyoptera Blattellidae
    Pest Management Science, 2016
    Co-Authors: Coby Schal, Jules Silverman
    Abstract:

    BACKGROUND Bait formulations are widely used to control German cockroach (Blattella germanica) populations. To perform optimally, these formulations must compete favorably with non-toxic alternative foods present within the insect's habitat. We hypothesized that the nutritional history of cockroaches and their acceptance or avoidance of glucose would affect their food preference and thus bait efficacy. To test this hypothesis, we conducted a controlled laboratory experiment, first providing glucose-accepting and glucose-averse cockroaches nutritionally defined diets and then offering them identical diets containing the insecticide hydramethylnon as a bait proxy to evaluate the effect of diets of differing macronutrient composition on bait performance. RESULTS The interaction between diet composition and bait composition affected the survival of adult males as well as first-instar nymphs exposed to excretions produced by these males. Survival analyses indicated different responses of glucose-averse and glucose-accepting insects, but generally any combination of diet and bait that resulted in high diet intake and low bait intake reduced secondary kill. CONCLUSIONS This study represents a comprehensive examination of the effect of alternative foods on bait efficacy. We suggest that disparities between the nutritional quality of baits and the foods that are naturally available could profoundly impact the management of German cockroach infestations. © 2016 Society of Chemical Industry.

  • electroantennogram responses and field trapping of asian cockroach dictyoptera Blattellidae with blattellaquinone sex pheromone of the german cockroach dictyoptera Blattellidae
    Environmental Entomology, 2015
    Co-Authors: Yvonne K Matos, Coby Schal
    Abstract:

    The Asian cockroach, Blattella asahinai Mizukubo, first introduced to Florida in 1986, has been spreading throughout the southeastern United States. Populations can reach extremely high densities and cause damage to crops as well as become a nuisance in residential settings. Because the German cockroach, Blattella germanica L., is its closest extant relative, we characterized the B. asahinai male response to blattellaquinone, the sex pheromone of the German cockroach, in an effort to develop monitoring tools for B. asahinai. Electroantennogram (EAG) analysis was conducted on B. asahinai and B. germanica males and females, and revealed that the antennae of males of both species responded significantly more to blattellaquinone than females, and in both males and females absolute EAG responses of B. asahinai were greater than in B. germanica males and females, respectively. However, normalized male EAG response curves and ED50 values (effective dose to elicit 50% of maximal response) did not differ significantly between the two species. Results of field trapping experiments demonstrated that male B. asahinai were more attracted to blattellaquinone than any other life stage, and 10 μg of blattellaquinone attracted the most males. These results suggest that blattellaquinone or a similar compound might be a component of the sex pheromone of B. asahinai females.

  • observations on the nesting and prey of the solitary wasp tachysphex inconspicuus with a review of nesting behavior in the t obscuripennis species group
    Journal of Insect Science, 2010
    Co-Authors: Frank E Kurczewski, Rollin E Coville, Coby Schal
    Abstract:

    The nesting behaviors of 10 females of Tachysphex inconspicuus (Kirby) (Hymenoptera: Crabronidae) were studied on a sandy, mowed lawn at the La Selva Biological Station in northeastern Costa Rica on 27–29 April 1980. Twenty-four completed nests were observed, excavated, and measured. The nests had oblique, short burrows leading to one or two shallow cells. Prey cockroaches belonging to 11 species of Chorisoneura and Riatia fulgida (Saussure) (Blattaria: Blattellidae), all tropical wet forest canopy indicator species, were removed from the cells, weighed, and identified. The cockroaches consisted mainly of adult females, selectively preyed upon over adult males and nymphs due to their larger sizes. The aggregate prey mass in cells was separable into prospective larger (heavier) female and smaller (lighter) male cells. Wasps usually oviposited on the heaviest cockroach in a cell, in most cases an adult female. Atypical genus behavior included (1) prey being carried to one side of the wasp and perhaps grasped by a hindleg during removal of the temporary entrance closure and nest entry and (2) wasp's egg being laid affixed to a forecoxal corium and extending backward in a longitudinally posteriad position across the prey's ventral thorax. A comparison with the nesting behavior of other species in the Tachysphex obscuripennis species group is made.

  • population genetic structure of the german cockroach blattodea Blattellidae in apartment buildings
    Journal of Medical Entomology, 2010
    Co-Authors: Jonathan Crissman, Warren Booth, Edward L. Vargo, D V Mukha, Richard G Santangelo, Coby Schal
    Abstract:

    ABSTRACT The German cockroach, Blattella germanica (L.) (Blattodea: Blattellidae), is a major residential pest with the potential to vector various pathogens and produce and disseminate household allergens. Understanding population genetic structure and differentiation of this important pest is critical to efforts to eradicate infestations, yet little is known in this regard. Using highly polymorphic microsatellite markers, we investigated patterns of genetic diversity and differentiation within and among 18 apartments from six apartment complexes located in Raleigh, NC. No departure from panmixia was found between rooms within apartments, indicating that active dispersal resulting in gene flow may occur among rooms within apartment units. Alternatively, aggregations within apartments may exist in relative isolation under a metapopulation framework, derived from a recent, common source. Thus, in the event of population control practices leading to incomplete cockroach eradication within an apartment, reco...

  • attractiveness of insecticide baits for cockroach control dictyoptera Blattellidae laboratory and field studies
    Journal of Economic Entomology, 2001
    Co-Authors: Godfrey Nalyanya, Robert J Kopanic, Dangsheng Liang, Coby Schal
    Abstract:

    Several insecticide bait formulations were evaluated for their attractiveness to cockroaches in olfactometer assays in the laboratory and in trapping experiments in the field. Included in the assays were bait stations, gels, pastes, and a powder that contained one of the following active ingredients: abamectin, boric acid, chlorpyrifos, or hydramethylnon. There were significant differences among the baits in their attractiveness to the German cockroach, Blattella germanica (L.). In trapping experiments, Avert powder (abamectin), Maxforce station and gel, and Siege gel (all hydramethylnon) were consistently attractive to B. germanica adults and nymphs. Laboratory olfactometer assays with adult males confirmed these results and showed that nymphs were as responsive as males whereas females were less responsive. Our bioassays also demonstrate that attractiveness of bait can be dramatically affected by the age of the bait. One week of aging significantly reduced the attractiveness of Avert powder in both laboratory and field assays. Aging, however did not diminish the attractiveness of Maxforce gel, indicating that the formulation may be critical for retention of attractiveness of baits. Baits that were most attractive to the German cockroach were also the most attractive to nymphs and adults of the brownbanded cockroach, Supella longipalpa (F.).

Arthur G. Appel - One of the best experts on this subject based on the ideXlab platform.

  • insecticide resistance of several field collected german cockroach dictyoptera Blattellidae strains
    Journal of Economic Entomology, 2017
    Co-Authors: Arthur G. Appel
    Abstract:

    German cockroaches, Blattella germanica (L.), remain one of the most difficult indoor insect species to control because of its ability to develop resistance to insecticides. The toxicity and resistance levels of five technical-grade insecticides (permethrin, chlorpyrifos, propoxur, imidacloprid, and fipronil) were determined for adult males of seven strains of the German cockroach, a laboratory-reared susceptible strain (S) and six field-collected strains (B, D, E, G, H, and I). Using topical application methods, fipronil was the most toxic insecticide to all seven strains. The LD50 values of fipronil in the susceptible strain (S) and the field-collected strains B, D, E, G, H, and I were 1.33, 2.62, 11.53, 5.07, 7.66, 5.15, and 10.15 ng/insect, respectively. The field-collected strains were most resistant to permethrin among the five insecticides, except for strain H. The resistance ratios of strains B, D, E, G, and I to permethrin were 31.8, 37.3, 51.9, 34.9, and 37.5, respectively. With a resistance ratio of 6.4, the field-collected strain H was most resistant to chlorpyrifos. The field-collected strains were not significantly resistant to propoxur. Strains B, H, and I were not significantly resistant to imidacloprid when compared with the susceptible strain. Based on the different resistance ratios for each insecticide, we conclude that there are high rates of insecticide resistance in German cockroaches from Franklin County, NC, and that the field-collected strains most likely had different treatment histories.

  • integrated pest management of the german cockroach blattodea Blattellidae in manufactured homes in rural north carolina
    Florida Entomologist, 2016
    Co-Authors: Beatrice N Dingha, Jeremy Oneal, Arthur G. Appel, Louis E N Jackai
    Abstract:

    Abstract The German cockroach, Blattella germanica (L.) (Blattodea: Blattellidae), is a serious pest in residential housing with control administered mainly through application of pesticides. Integrated pest management (IPM) involves a combination of strategies aimed at reducing pest populations. Over a 27 mo study period, we determined levels of German cockroach populations in rural manufactured residential homes: before IPM implementation (Pre-IPM), the period when residents were educated on IPM strategies (IPM-education), and during education and insecticide application (IPM-education plus bait). Sanitation level in the IPM-education phase (2.8) was significantly different from that in the Pre-IPM phase (3.9) and was accompanied by a decrease in trap catch. Sticky and jar traps were deployed in kitchen areas to assess levels of infestation. Trap catch from all participants during the 3 phases was significantly different. Mean cockroach catch per participant per trap was 20.5 ± 4.1 during Pre-IPM, 13.2 ...

  • mulch preferences of the asian cockroach dictyoptera Blattellidae
    Journal of Economic Entomology, 2013
    Co-Authors: Edward T. Snoddy, Arthur G. Appel
    Abstract:

    Mulch preferences of the Asian cockroach, Blattella asahinai Mizukubo, were determined in a series of laboratory experiments. Because this species is a peridomestic pest, mulch preferences may be a key part of an integrated pest management program for homeowners. Five mulches were used: cypress, oak leaf litter, pine straw, rubber, and topsoil. Large arena experiments showed that adult male Asian cockroaches preferred oak leaf litter and pine straw, while adult females preferred oak leaf litter and rubber mulches. Nymphal stages preferred rubber (48.3–62.5% for small and medium instars, respectively) to all other mulches. All stages of the Asian cockroach showed very little preference to topsoil (0%) and cypress mulch (6.3%). Ebeling choice box tests confirmed lack of preference or repellency of adult males to topsoil (17.8 ± 3.6%) and rubber mulch (15.7 ± 3.6%). Continuous exposure experiments indicated that pine straw was significantly more toxic to adult males than other mulches (66.7 ± 18.4% mortality at 7 d). Mulch preferences of the Asian cockroach may be mediated by characteristics of the interstitial spaces in the different mulches. Rubber mulch afforded smaller, more humid spaces that were inaccessible to adults. Because cypress mulch was least preferred by nymphs and adults, use of cypress mulch in an integrated pest management program around homes may help to reduce Asian cockroach populations and limit insecticide exposure to humans, animals, and the environment.

  • fumigant toxicity of essential oils to the german cockroach dictyoptera Blattellidae
    Journal of Economic Entomology, 2010
    Co-Authors: Alicia K Phillips, Arthur G. Appel
    Abstract:

    The fumigant toxicity of 12 essential oil components [carvacrol, 1,8-cineole, trans-cinnamaldehyde, citronellic acid, eugenol, geraniol, S-(-)-limonene, (-)-linalool, (-)-menthone, (+)-alpha-pinene, (-)-beta-pinene, and thymol] to adult male, adult female, gravid female, and large, medium, and small nymphs of the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae), was determined. 1,8-Cineole was the most toxic essential oil component to adult males and females, gravid females, and large nymphs, with LC50 values of 6.8, 8.4, 5.3, and 11.4 mg/liter air at 24 h, respectively. (-)-Menthone and carvacrol were the most toxic essential oil components to medium and small nymphs, with LC50 values of 9.0 and 3.6 mg/liter air at 24 h, respectively. Citronellic acid was the least toxic essential oil component to all stages of the German cockroach. There was not a consistent relationship between body mass and toxicity; the susceptibility of the stages differed for each oil. LC50 values of all stages were correlated negatively with vapor pressure and positively with molecular weight of the essential oil components. The most toxic essential oil components to the majority of cockroach stages were cyclic aliphatic hydrocarbons [1,8-cineole, (-)-menthone, (+)-alpha-pinene, (-)-beta-pinene, and S-(-)-limonene]. Ring size and the presence of a carbonyl functional group also may have contributed to the toxicity of the compounds. Citronellic acid had no effect on ootheca hatch (100% hatch), whereas (-)-menthone had the greatest effect on ootheca hatch (73% hatch). Percentage of hatched oothecae decreased linearly with increasing concentration for (-)-menthone, S-(-)-limonene, (+)-alpha-pinene, and (-)-beta-pinene. No essential oil component prevented ootheca hatch, suggesting that multiple treatments would be required in the field to eliminate infestations.

  • topical toxicity of essential oils to the german cockroach dictyoptera Blattellidae
    Journal of Economic Entomology, 2010
    Co-Authors: Alicia K Phillips, Arthur G. Appel, Steven R Sims
    Abstract:

    The fumigant toxicity of 12 essential oil components [carvacrol, 1,8-cineole, trans-cinnamaldehyde, citronellic acid, eugenol, geraniol, S-(-)-limonene, (-)-linalool, (-)-menthone, (+)-alpha-pinene, (-)-beta-pinene, and thymol] to adult male, adult female, gravid female, and large, medium, and small nymphs of the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae), was determined. 1,8-Cineole was the most toxic essential oil component to adult males and females, gravid females, and large nymphs, with LC50 values of 6.8, 8.4, 5.3, and 11.4 mg/liter air at 24 h, respectively. (-)-Menthone and carvacrol were the most toxic essential oil components to medium and small nymphs, with LC50 values of 9.0 and 3.6 mg/liter air at 24 h, respectively. Citronellic acid was the least toxic essential oil component to all stages of the German cockroach. There was not a consistent relationship between body mass and toxicity; the susceptibility of the stages differed for each oil. LC50 values of all stages were correlated negatively with vapor pressure and positively with molecular weight of the essential oil components. The most toxic essential oil components to the majority of cockroach stages were cyclic aliphatic hydrocarbons [1,8-cineole, (-)-menthone, (+)-alpha-pinene, (-)-beta-pinene, and S-(-)-limonene]. Ring size and the presence of a carbonyl functional group also may have contributed to the toxicity of the compounds. Citronellic acid had no effect on ootheca hatch (100% hatch), whereas (-)-menthone had the greatest effect on ootheca hatch (73% hatch). Percentage of hatched oothecae decreased linearly with increasing concentration for (-)-menthone, S-(-)-limonene, (+)-alpha-pinene, and (-)-beta-pinene. No essential oil component prevented ootheca hatch, suggesting that multiple treatments would be required in the field to eliminate infestations.

Hernández Ramírez Gabriela - One of the best experts on this subject based on the ideXlab platform.

  • Cebos para el econtrol de la cucaracha alemana Blatella germanica (Dictyoptera: Blattellidae) formulados con hongos entomopatógenos y ácido bórico.
    Colegio de Postgraduados (COLPOS), 2013
    Co-Authors: Hernández Ramírez Gabriela
    Abstract:

    Blattella germanica (Dictyoptera: Blattellidae) es la especie más importante de las cucarachas sinantrópicas en el mundo. En este trabajo se evaluó la patogenicidad de aislamientos de Metarhizium anisopliae, M. pingshaense y Beauveria bassiana en ninfas y adultos de B. germanica. Para ofrecer una alternativa al uso de insecticidas en el manejo de B germanica, se desarrolló una formulación de cebo en polvo y pellet. Se determinó la preferencia de adultos de esta cucaracha, a diferentes dosis de azúcar glas (0.125, 0.25, 0.5, 0.75M) como fagoestimulante y se evaluó la compatibilidad del ácido bórico con los hongos M anisopliae y B bassiana en estos cebos. Finalmente, se evaluó vía oral, la virulencia de cebos formulados con azúcar glas 0.5 M, ácido bórico (0.5, 1, 2, 4%) y esporas de aislamientos de M. anisopliae (Ma2, Ma3, Ma7) y M. pingshaense (Ma5) contra ninfas de quinto ínstar de B. germanica. Se confirmó la diferencia de susceptibilidad de ninfas y adultos de la cucaracha alemana a estos hongos y se demostró que las ninfas de quinto instar de B. germanica son menos susceptibles a la infección por estos entomopatógenos. El valor de CL50 para los aislamientos fue de 1 - 3 x 107 esporas / mL. La concentración de azúcar glas más atractiva fue 0.5 M. La combinación de 2% de ácido bórico (AB) con esporas de M. anisopliae y B. bassiana no afectó la viabilidad de estos hongos. Los resultados de la evaluación oral de los cebos con ácido bórico y Metarhizium sobre ninfas de la cucaracha alemana causó mortalidades de 100% y el mejor TL50 fue 10 d para los cebos con 2% de ácido bórico. La mejor formulación fue, pellet con 2% AB y 2 x 108 esporas / g de cebo. Estos resultados demuestran un efecto sinérgico entre el AB y Metarhizium y ofrecen una alternativa potencial para el manejo de B. germanica. _______________ BAIT FOR CONTROL OF THE GERMAN COCKROACH Blattella germanica (DICTYOPTERA: Blattellidae) MADE WITH ENTOMOPATHOGENIC FUNGI AND BORIC ACID. ABSTRACT: Blattella germanica (Dictyoptera: Blattellidae) is the most important specie of synanthropic cockroaches in the world. In this study we evaluated the pathogenicity of isolates of Metarhizium anisopliae, M. pingshaense and Beauveria bassiana in nymphs and adults of B. germanica. To offer an alternative to the use of insecticides in the control of B germanica, developed a bait formulation in powder and pellet. We determined the preference of adults of this cockroach, at different doses of sugar (0.125, 0.25, 0.5, 0.75M) as phagostimulant and assessed the compatibility of boric acid with the fungus M anisopliae and B bassiana on these baits. Finally, we evaluated orally baits virulence 0.5M formulated with sugar, boric acid (0.5, 1, 2, 4%) and spore of M. anisopliae (Ma2, Ma3, MA7) and M. pingshaense (MA5) against fifth-instar nymphs of B. germanica. Differences in susceptibility of nymphs and adults of the German cockroach to these entomopathogenic fungi were confirmed and shown that fifth instar nymphs of B. germanica are less susceptible to infection. The LC50 value for the isolates was 1 to 3 x 107 spores / mL. Sugar concentration was 0.5 M more attractive. The combination of 2% boric acid (AB) with spores of M. anisopliae and B. bassiana did not affect the viability of these fungi. The oral evaluation results of boric acid baits and Metarhizium on German cockroach nymphs caused 100% mortality and LT50 was 10 d for baits with 2% boric acid. The best formulation was, pellet with 2% AB and 2 x 108 spores / g of bait. These results demonstrate a synergistic effect between the AB and Metarhizium and offer a potential alternative for the management of B. germanica

  • Cebos para el econtrol de la cucaracha alemana Blatella germanica (Dictyoptera: Blattellidae) formulados con hongos entomopatógenos y ácido bórico.
    Colegio de Postgraduados (COLPOS), 2013
    Co-Authors: Hernández Ramírez Gabriela
    Abstract:

    Blattella germanica (Dictyoptera: Blattellidae) es la especie más importante de las cucarachas sinantrópicas en el mundo. En este trabajo se evaluó la patogenicidad de aislamientos de Metarhizium anisopliae, M. pingshaense y Beauveria bassiana en ninfas y adultos de B. germanica. Para ofrecer una alternativa al uso de insecticidas en el manejo de B germanica, se desarrolló una formulación de cebo en polvo y pellet. Se determinó la preferencia de adultos de esta cucaracha, a diferentes dosis de azúcar glas (0.125, 0.25, 0.5, 0.75M) como fagoestimulante y se evaluó la compatibilidad del ácido bórico con los hongos M anisopliae y B bassiana en estos cebos. Finalmente, se evaluó vía oral, la virulencia de cebos formulados con azúcar glas 0.5 M, ácido bórico (0.5, 1, 2, 4%) y esporas de aislamientos de M. anisopliae (Ma2, Ma3, Ma7) y M. pingshaense (Ma5) contra ninfas de quinto ínstar de B. germanica. Se confirmó la diferencia de susceptibilidad de ninfas y adultos de la cucaracha alemana a estos hongos y se demostró que las ninfas de quinto instar de B. germanica son menos susceptibles a la infección por estos entomopatógenos. El valor de CL50 para los aislamientos fue de 1 - 3 x 107 esporas / mL. La concentración de azúcar glas más atractiva fue 0.5 M. La combinación de 2% de ácido bórico (AB) con esporas de M. anisopliae y B. bassiana no afectó la viabilidad de estos hongos. Los resultados de la evaluación oral de los cebos con ácido bórico y Metarhizium sobre ninfas de la cucaracha alemana causó mortalidades de 100% y el mejor TL50 fue 10 d para los cebos con 2% de ácido bórico. La mejor formulación fue, pellet con 2% AB y 2 x 108 esporas / g de cebo. Estos resultados demuestran un efecto sinérgico entre el AB y Metarhizium y ofrecen una alternativa potencial para el manejo de B. germanica. _______________ BAIT FOR CONTROL OF THE GERMAN COCKROACH Blattella germanica (DICTYOPTERA: Blattellidae) MADE WITH ENTOMOPATHOGENIC FUNGI AND BORIC ACID. ABSTRACT: Blattella germanica (Dictyoptera: Blattellidae) is the most important specie of synanthropic cockroaches in the world. In this study we evaluated the pathogenicity of isolates of Metarhizium anisopliae, M. pingshaense and Beauveria bassiana in nymphs and adults of B. germanica. To offer an alternative to the use of insecticides in the control of B germanica, developed a bait formulation in powder and pellet. We determined the preference of adults of this cockroach, at different doses of sugar (0.125, 0.25, 0.5, 0.75M) as phagostimulant and assessed the compatibility of boric acid with the fungus M anisopliae and B bassiana on these baits. Finally, we evaluated orally baits virulence 0.5M formulated with sugar, boric acid (0.5, 1, 2, 4%) and spore of M. anisopliae (Ma2, Ma3, MA7) and M. pingshaense (MA5) against fifth-instar nymphs of B. germanica. Differences in susceptibility of nymphs and adults of the German cockroach to these entomopathogenic fungi were confirmed and shown that fifth instar nymphs of B. germanica are less susceptible to infection. The LC50 value for the isolates was 1 to 3 x 107 spores / mL. Sugar concentration was 0.5 M more attractive. The combination of 2% boric acid (AB) with spores of M. anisopliae and B. bassiana did not affect the viability of these fungi. The oral evaluation results of boric acid baits and Metarhizium on German cockroach nymphs caused 100% mortality and LT50 was 10 d for baits with 2% boric acid. The best formulation was, pellet with 2% AB and 2 x 108 spores / g of bait. These results demonstrate a synergistic effect between the AB and Metarhizium and offer a potential alternative for the management of B. germanica.Tesis (Doctorado en Ciencias, especialista en Entomología y Acarología).- Colegio de Postagraduados, 2013.Consejo Nacional de Ciencia y Tecnología (CONACYT)

Young-joon Ahn - One of the best experts on this subject based on the ideXlab platform.

  • monitoring for insecticide resistance in field collected populations of blattella germanica blattaria Blattellidae
    Journal of Asia-pacific Entomology, 2010
    Co-Authors: Kyu Sik Chang, Hyun E Shin, Jin Sung Jung, Chan Park, Young-joon Ahn
    Abstract:

    Abstract Seven field-collected populations of German cockroach, Blattella germanica (L.) (ICN, DNH, CHN, DGU, BSN, GSN, and GWJ), were tested for susceptibility to eight different insecticides by a topical application method, and were compared to an insecticide-susceptible KSS strain. Marked regional variations of insecticide susceptibility were observed. Extremely high to high levels of resistance were observed in bifenthrin [resistance ratio (RR), 46–159], deltamethrin (RR, 61–160), and esfenvalerate [RR, 70–270; except for BSN females (RR, 20) and GSN females (RR, 24)]. Low to moderate levels of resistance were observed in cypermethrin [RR, 16–29; except for DGU females (RR, 88) and BSN females (RR, 41)], permethrin [RR, 11–39; except for DNH females (RR, 110) and BSN females (RR, 44)], chlorpyrifos [RR, 2–13; except for GSN and GWJ females (RR, ca. 140)], chlorpyrifos-methyl (RR, 2–8), and fenthion (RR, 8–17). All of the colonies were susceptible to one or more of the insecticides examined. These results indicate that careful selection and rotational use of these insecticides should result in continued satisfactory control against field populations of German cockroach.

  • Toxicity of Myristica fragrans Seed Compounds Against Blattella germanica (Dictyoptera: Blattellidae)
    Journal of Medical Entomology, 2007
    Co-Authors: Woo-chul Jung, Young-su Jang, Tran Trung Hieu, Chong-kyu Lee, Young-joon Ahn
    Abstract:

    The insecticidal constituents of hexane-soluble fraction from a methanolic extract of the seeds from Myristica fragrans (Myristicaceae) against adult females of Blattella germanica (L.) (Dictyoptera: Blattellidae) were analyzed by gas chromatography and gas chromatography-mass spectrometry. The insecticidal activity of 13 Myristica seed compounds against female B. germanica was examined by using the Þlter-paper contact toxicity and vapor phase toxicity bioassays. Results were compared with those of the other 23 known compounds of Myristica seed and currently used insecticides: dichlorvos, deltamethrin, permethrin, and propoxur. In contact toxicity tests using female

  • toxicity of myristica fragrans seed compounds against blattella germanica dictyoptera Blattellidae
    Journal of Medical Entomology, 2007
    Co-Authors: Woo-chul Jung, Young-su Jang, Tran Trung Hieu, Chong-kyu Lee, Young-joon Ahn
    Abstract:

    The insecticidal constituents of hexane-soluble fraction from a methanolic extract of the seeds from Myristica fragrans (Myristicaceae) against adult females of Blattella germanica (L.) (Dictyoptera: Blattellidae) were analyzed by gas chromatography and gas chromatography-mass spectrometry. The insecticidal activity of 13 Myristica seed compounds against female B. germanica was examined by using the filter-paper contact toxicity and vapor phase toxicity bioassays. Results were compared with those of the other 23 known compounds of Myristica seed and currently used insecticides: dichlorvos, deltamethrin, permethrin, and propoxur. In contact toxicity tests using female B. germanica, (IS)-(-) -beta-pinene (0.06 mg/cm2) was the most toxic insecticide, based on 24-h LD50 values. The insecticidal activity of this compound was comparable with that of permethrin (0.05 mg/cm2). (1R)-(+) -Camphor, (1S)-(-) -camphor, dipentene, (1R)-(+) -3-pinene, and (+)-alpha-terpineol (0.10-0.14 mg/cm2) were more toxic than propoxur (0.19 mg/cm2). (E)-Sabinene hydrate and propoxur were almost equitoxic. Potent insecticidal activity also was observed with (R)-(+) -citronellal, (S)-(-) -citronellal, (R)-(-) -alpha-phellandrene, (1S)-(-) -alpha-pinene, (1R)-(+) -alpha-pinene, and safrole (0.27-0.48 mg/cm2). In vapor phase toxicity tests, the compounds tested were effective in closed but not in open containers. These results indicate that the effect of these compounds was largely a result of action in the vapor phase. Myristica seed compounds described merit further study as potential insecticides or as leads for the control of cockroaches.

Bellés Xavier - One of the best experts on this subject based on the ideXlab platform.

  • Determination of allatostatin levels in relation to the gonadotropic cycle in the female of Blattella germanica (L.) (Dictyoptera, Blattellidae)
    'Wiley', 2017
    Co-Authors: Vilaplana Lluïsa, Maestro, José L., Piulachs Maria-dolors, Bellés Xavier
    Abstract:

    A polyclonal antibody against the allatostatin BLAST-3 (AGSDGRLYSFGL-NH2) of the cockroach Blattella germanica (L.) (Dictyoptera, Blattellidae) has been raised and characterized, and an ELISA (enzyme-linked immunosorbent assay) for allatostatin quantification has been developed. Allatostatin contents in brain, midgut and haemolymph have been measured in females of B. germanica during the first gonadotropic cycle. Brain allatostatin content increases steadily from adult emergence to the formation of the first ootheca. The values range from 2 ng/brain on the day of adult emergence to 25 ng/brain when the insect forms the ootheca 8 days later. In the midgut, the pattern is similar but the values are about half those of the brain. Allatostatin concentrations in the haemolymph after HPLC separation are in the nanomolar range. The occurrence of allatostatins in the haemolymph suggests that these peptides can act through a humoral pathway, as well as via nerves. The allatostatin content of both brain and midgut are high while the female is transporting the ootheca, which suggests that these peptides could be related to the low metabolic status characterizing the period of oothecal transport.Financial support from the DGICYT, Spain (project No PB95-0062); from the CIRIT, Catalonia (1995 SGR 00059) and from the Institut d'Estudis Catalans (IEC, Barcelona) is gratefully acknowledged.Peer Reviewe

  • Juvenile hormone inhibition in corpora allata from ovariectomized Blatella germanica
    'Wiley', 2017
    Co-Authors: Maestro, José L., Piulachs Maria-dolors, Danés Maria-dolors, Cassier Pierre, Bellés Xavier
    Abstract:

    Ovariectomy has been used to study the role of the ovary in endocrine homeostasis. Our studies on young virgin adults of the cockroach Blattella germanica (L.) (Dictyoptera, Blattellidae) show that the cytological development of the corpora allata (CA) in ovariectomized females proceeds as in intact specimens, whereas the rates of Juvenile Hormone (JH) synthesis are lower. Stimulation of the CA from ovariectomized females in vitro by mevalonolactone suggests that enzymatic mechanisms which follow mevalonate formation in the biosynthetic pathway are functional. The synthetic capabilities of these CA are also illustrated by the kinetics of JH production in vitro, because hormonal release increases with time to reach 'normal' levels after 8h of incubation. Our data suggest that the absence of ovaries leads to effective inhibition of JH biosynthesis rather than to an impairment of the developmental process in the CA cells.Peer Reviewe

  • Papel de la hormona juvenil en la embriogénesis de la cucaracha Blattella germanica (Dictyoptera, Blattellidae)
    2016
    Co-Authors: Fernández-nicolas Ana, Bellés Xavier
    Abstract:

    Trabajo presentado en el V Congreso de la Sociedad Española de Biología Evolutiva (SESBE 2016), celebrado en Murcia del 18 al 21 de enero de 2016.Resultados recientes han cuestio nado que la hormona juvenil (HJ) de los insectos tenga funciones clave en la embriogénesis. Los resultados más concluyentes se han obtenido en el holometábolo Bombyx mori (Lepidoptera, Bombycidae) (Daimon et al., 2015). Hemos abordado esta cuestión en el hemimetábolo Blattella germanica (Dictyoptera, Blattellidae) mediante RNAi maternal, silenciando la expresión de la O-metil-transferasa de la HJ (enzima clave de la biosíntesis de dicha hormona), Methoprene tolerant (Met) y Taiman (receptor y co-receptor de la HJ) y Kruppel-homolog 1 (factor de transcripción que transduce la señal de la HJ). Los perfiles de expresión coinciden con el de niveles de HJ que se observan entre el 50% y 90% del desarrollo. La RNAi produce efectos fenotípicos similares en los cuat ro genes: un 48% de los embriones alcanzan un desarrollo prácticamente normal, pero no logran eclosionar, mientras que el 52% restante eclosiona normalmente. Los resultados son similares a los descritos en B. mori , lo cual indica que la función de la JH de mostrada en esos estudios, facilitar la eclosión de la primera ninfa, está conservada en hemimetábolos y holometábolos.N