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Gregg Henderson - One of the best experts on this subject based on the ideXlab platform.

  • Horizontal Transfer of Spinosad in Coptotermes formosanus (Isoptera: Rhinotermitidae).
    Journal of economic entomology, 2016
    Co-Authors: D. Bhatta, Gregg Henderson
    Abstract:

    Slow-acting and nonrepellent termiticides are possible candidates for nestmate to nestmate transfer called horizontal transfer. For the horizontal transfer study of spinosad, Coptotermes formosanus Shiraki was released in sand and soil at 1, 25, and 50 ppm Entrust® for 1 h and then mixed with healthy untreated termites for 21 d at the ratio of 1:1. Donor and recipient termites began to contact and groom each other immediately after release. Mortality of termites was recorded at 1, 3, 7, and 14 d after treatment. Spinosad was more effectively transferred in sand than in soil. In sand at 25 and 50 ppm, significantly high mortality of donors and recipients was observed after 7 d. When termites were exposed to treated soil at day 21, all three concentrations resulted in significantly higher mortality compared to the control. In our laboratory study, spinosad was effectively transferred by donor termites. Transfer of spinosad depended on its bioavailability and concentration. Further study is needed to address its effects against C. formosanus under field conditions.

  • panic escape polyethism in worker and soldier Coptotermes formosanus isoptera rhinotermitidae
    Insect Science, 2016
    Co-Authors: Cai Wang, Gregg Henderson, Bal K. Gautam, Jie Chen, Dependra Bhatta
    Abstract:

    Termites were the first animal to form societies. Two hundred million years of evolution provide for a multitude of innate social behaviors that can be experimentally dissected. These fine-tuned patterns of behavior are especially interesting when observing group decision making in the panic mode. In this study, we examined behavioral patterns of termites under panic conditions to gain insight into how an escape flow self-organizes. One hundred worker and 10 soldier Coptotermes formosanus were released into agar plates. After a disturbance was created most workers followed each other and ran along the wall of dishes, thus forming a unidirectional escape flow, whereas soldiers showed a significantly higher frequency of moving to the center of the arena or on periphery of the escape flow as compared to workers. Agonistic behavior was usually observed as soldiers moved to center or periphery. This is the first report on the behavioral repertoire of termites when panicked, with details on the behavioral polymorphism of workers and soldiers during an escape.

  • Water Transport by Coptotermes formosanus (Isoptera: Rhinotermitidae).
    Environmental entomology, 2014
    Co-Authors: Bal K. Gautam, Gregg Henderson
    Abstract:

    Subterranean termites are extremely vulnerable to desiccation, and high moisture makes their habitat and food favorable for survival and colony growth. Although there is a general perception that termites can manipulate moisture, documentation is surprisingly scanty with regard to how termites transport water and the factors that impact it. There has been no study of water transfer by Coptotermes formosanus Shiraki, a notoriously invasive termite in the southern United States. We conducted a study to determine if C. formosanus transfers water. Bioassays using arenas with a dry food source connected to a moist substrate by either a short tube (10 cm) or a long tube (100 cm) were conducted. Three moistened substrate types were tested to see how they impacted water transfer. In addition, workers and soldiers sampled from a moist sand substrate were dissected to determine water sac volumes for possible transfer of water to wood. The results indicated that some water transfer is achieved by the evacuation of water sacs. However, moist soil was also moved to increase humidity. When termites had use of moist silty clay, wood moisture gain increased significantly in both 10 and 100 cm tubes. As tube distance increased, moisture to the more distant food source decreased. Workers had the largest water sacs, though soldiers appear to contribute in water transfer via water sacs as well. Water transfer and its implications are discussed.

  • Increased search tunnel formation by Coptotermes formosanus shiraki (Isoptera : Rhinotermitidae) in 2-phenoxyethanol treated sand
    Journal of Entomological Science, 2005
    Co-Authors: H X Fei, A Fugler, Gregg Henderson, Raili A. Laine
    Abstract:

    Termites follow chemical and physical gradients in their search for food. In laboratory bioassays, search tunnel formation of Coptotermes formosanus Shiraki was examined in response to different 2-phenoxyethanol concentrations in sand. 2-phenoxyethanol significantly increased the total tunnel network length by termites. At a concentration of 0.082%, but not 0.164%, it also significantly increased daily search activity by C. formosanus. After aging the treated sand for 2 wks, C. formosanus continued to show a significant increase in the search tunnel length in 0.082% 2-phenoxyethanol treatments. Application of 2-phenoxyethanol, a nonpheromone attractant, to termite infested soil nearby, may increase the search and thus the likelihood for contact with baits and nonrepellent termiticides in the field

  • Field evaluation of nootkatone and tetrahydronootkatone as wood treatments against Coptotermes formosanus
    Sociobiology, 2003
    Co-Authors: Karen E. Nix, Gregg Henderson, Roger A Laine
    Abstract:

    A component of Alaskan yellow cedar, citrus oil, and vetiver oil, nootkatone, and its derivative, tetrahydronootkatone, were tested for their potential as wood treatments against Coptotermes formosanus. Wood treatments dipped in 1% and 5% nootkatone and tetrahydronootkatone in ethanol or vacuum impregnated (5% only) were tested in a natural setting using termite-infested bald cypress trees along the Calcasieu River in Westlake, Louisiana. Results showed no significant difference in the consumption of the control wood and wood treated with 1% nootkatone or tetrahydronootkatone solutions. Both trials testing the 5% dip method and one trial testing the 5% impregnated wood, for both nootkatone and tetrahydronootkatone, were significantly different from control wood and show good potential as a wood preservative.

Roger A Laine - One of the best experts on this subject based on the ideXlab platform.

Weste L A Osbrink - One of the best experts on this subject based on the ideXlab platform.

  • activity of 1 4 benzoquinones against formosan subterranean termites Coptotermes formosanus
    Journal of Agricultural and Food Chemistry, 2008
    Co-Authors: Kobaisy Mozaina, Alan R Lax, Charles L Cantrell, Amelia B Mims, Maria R Tellez, Weste L A Osbrink
    Abstract:

    A large number of naturally occurring and synthetic benzoquinones were evaluated for activity against the Formosan subterranean termite, Coptotermes formosanus, with potential use in termite control. Among these bioactive naturally occurring benzoquinones are 2-methyl-5-isopropyl-1,4-benzoquinone, 2-methoxy-6-pentyl-1,4-benzoquinone, 2,3-dimethoxy-5-methyl-6-(3-methyl-2-butenyl)-1,4-benzoquinone, 2,3-dimethoxy-5,6-dimethyl-1,4-benzoquinone, and 2,3-dichloro-5,6-dimethyl-1,4-benzoquinone. All five of these compounds demonstrated 100% mortality against C. formosanus by day 11 at a concentration of 1% (wt/wt) or less. In general, benzoquinones with one or two hydrophobic groups on the 5 and/or 6 positions of the quinone ring along with one or two group(s) on the opposite side of the ring, at the 2 and/or 3 position, led to high rates of mortality against C. formosanus. Quantitative structure-activity relationship (QSAR) studies showed no correlation between lipophilicity (calculated log P) and mortality for the entire group of nonhalogenated benzoquinones. A correlation was observed between C-6 chain length and day 3 percent mortality for 2,3-dimethoxy-5-methyl-6-substituted aliphatic benzoquinones where short chain lengths resulted in higher mortality.

  • plant derived natural products exhibiting activity against formosan subterranean termites Coptotermes formosanus
    Pest Management Science, 2006
    Co-Authors: Kumudini M. Meepagala, Weste L A Osbrink, George Sturtz, Alan R Lax
    Abstract:

    The Formosan subterranean termite, Coptotermes formosanus Shiraki, is among the most devastating termite pests. Natural products derived from plant extracts were tested in a discovery programme for effective, environmentally friendly termite control agents. Among the natural products tested, vulgarone B (isolated from Artemisia douglasiana Besser), apiol (isolated from Ligusticum hultenii (Fern.) Calder & Taylor) and cnicin (isolated from Centaurea maculosa Lam.) exhibited significantly higher mortalities than in untreated controls in laboratory bioassay. These compounds are present at high levels in their respective plant sources and also possess other biological activities such as phytotoxic and antifungal properties.

  • Plant‐derived natural products exhibiting activity against formosan subterranean termites (Coptotermes formosanus)
    Pest management science, 2006
    Co-Authors: Kumudini M. Meepagala, Weste L A Osbrink, George Sturtz, Alan R Lax
    Abstract:

    The Formosan subterranean termite, Coptotermes formosanus Shiraki, is among the most devastating termite pests. Natural products derived from plant extracts were tested in a discovery programme for effective, environmentally friendly termite control agents. Among the natural products tested, vulgarone B (isolated from Artemisia douglasiana Besser), apiol (isolated from Ligusticum hultenii (Fern.) Calder & Taylor) and cnicin (isolated from Centaurea maculosa Lam.) exhibited significantly higher mortalities than in untreated controls in laboratory bioassay. These compounds are present at high levels in their respective plant sources and also possess other biological activities such as phytotoxic and antifungal properties.

  • Natural products as pesticidal agents for control of the formosan termite (Coptotermes formosanus Shiraki)
    Sociobiology, 2003
    Co-Authors: Mario R. Tellez, Weste L A Osbrink, Mozaina Kobaisy
    Abstract:

    An overview of the literature on investigations of natural products for use against the termite pest Coptotermes formosanus. Our current results in this field are also presented. Results obtained from components of natural sources known to be associated with antitermite activity are presented. Results from additional studies on groups of compounds with structural features known or suspected to be associated with antitermite activity, quinones (benzo- naphtho- andanthra-), are also presented.

  • insecticide susceptibility in Coptotermes formosanus and reticulitermes virginicus isoptera rhinotermitidae
    Journal of Economic Entomology, 2001
    Co-Authors: Weste L A Osbrink, Alan R Lax, Richard J Brenner
    Abstract:

    Lethal time to mortality responses were established for eight insecticides against workers and soldiers of the Formosan subterranean termite, Coptotermes formosanus Shiraki, and workers of Reticulitermes virginicus (Banks). There were significant differences in the tolerance ratios between workers of C. formosanus colonies to all toxicants tested except fipronil. One colony was 16 times more tolerant than another to deltamethrin. C. formosanus soldiers had significant differences in tolerance ratios among colonies exposed to all toxicants except chlorpyrifos. Methoxychlor, permethrin, deltamethrin, and fipronil did not kill soldiers from two, one, one, and three colonies, respectively, within 8 h. Seventy-five percent of R. virginicus colonies were significantly less susceptible than the most susceptible colony to chlordane, methoxychlor, chlorpyrifos, cypermethrin, and fipronil, with 50% of the colonies less susceptible to permethrin and bendiocarb. In 50% of C. formosanus colonies the worker lethal time curves displayed substantial flattening in response to permethrin, and deltamethrin. Lethal time curves for C. formosanus soldiers exposed to chlordane, chlorpyrifos, permethrin, cypermethrin, deltamethrin, and bendiocarb showed substantial flattening. R. virginicus workers demonstrated substantial curve flattening when exposed to chlordane, methoxychlor, chlorpyrifos, deltamethrin, and fipronil. These findings indicate substantial inter-colony and intra-colony differences in susceptibility to insecticides.

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

  • behavioral changes in the termite Coptotermes formosanus isoptera inoculated with six fungal isolates
    Journal of Invertebrate Pathology, 2011
    Co-Authors: Aya Yanagawa, Tsuyoshi Yoshimura, Nao Fujiwaratsujii, Toshiharu Akino, Takashi Yanagawa, Susumu Shimizu
    Abstract:

    The studies of pathogen-prevention behaviors of termites have focused on hygiene behavior directed only against highly virulent pathogens. Therefore, we compared behavioral changes in the subterranean termite Coptotermes formosanus following contact with entomopathogenic fungi with different levels of virulence. The fungal virulence was inferred from the daily mortality and the LD50 value in previous data. When untreated termites were allowed to contact their fungus-inoculated nestmates, mutual grooming was frequent during 30 min after inoculation. The inoculated termites were often attacked and eaten by their uninoculated nestmates, and then buried after death. Notably, there was no influence of fungal virulence on these pathogen-prevention behaviors. However, the fungal isolates and genera affected not only the frequency of the behaviors but also the horizontal transmission pattern, the number of dead individuals and the survival period before the first death following infection.

  • Influence of Fungal Odor on Grooming Behavior of the Termite, Coptotermes formosanus
    Journal of insect science (Online), 2010
    Co-Authors: Aya Yanagawa, Fumio Yokohari, Susumu Shimizu
    Abstract:

    The termite Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) protects itself from entomopathogenic fungus by mutual grooming behavior. C. formosanus removes foreign organisms, such as fungal conidia, from the body surface of its nestmates by mutual grooming behavior and eating them. The conidia removal rate from the body surface differed according to the isolate of entomopathogenic fungi (Beauveria brongniartii 782, Paecilomyces fumosoroseus K3, and Metarhizium anisopliae 455), and the removal rate of the fungal isolates seemed to depend on feeding preference, which was detrmined using paper discs moistened with a fungal suspension. In addition, it was found that C. formosanus without antennae groomed their nestmates more frequently than those with antennae. Consequently, it seems that C. formosanus antennae detect substances without touching, such as via odor, and it affects the efficiency of grooming behavior. The results of single sensillum recording support the hypothesis that C. formosanus are capable of distinguishing three species of fungi by their odors.

  • Classification and distribution of antennal sensilla of the termite Coptotermes formosanus (Isoptera: Rhinotermitidae).
    Sociobiology, 2009
    Co-Authors: Aya Yanagawa, Susumu Shimizu, Kana Noma, Michiko Nishikawa, Ogino Kazumasa, Fumio Yokohari
    Abstract:

    Much more information about nature of termites is necessary to develop biological control methods. Hence, better understanding about the antennal sensory system will support this development. From this perspective, the antennal sensilla of the termite Coptotermes formosanus Shirakiwere classified into nine types on the basis of the external structures of the cuticular apparatus of the sensilla and their distribution was clarified using scanning electron microscopy. The classified antennal sensillawere as follows: chaeticum I, II and III, s. trichodeum I and II, s. basiconicum, s. capitulum, s. campaniformium and marginal sensillum. We have illustrated the morphological features of these sensilla and discussed their supposed functions on the basis of their structural and distributional characteristics.

  • Defense mechanism of the termite, Coptotermes formosanus Shiraki, to entomopathogenic fungi.
    Journal of invertebrate pathology, 2007
    Co-Authors: Aya Yanagawa, Fumio Yokohari, Susumu Shimizu
    Abstract:

    Termites, Coptotermes formosanus Shiraki, reared individually, were highly susceptible to entomopathogenic fungi, Paecilomyces fumosoroseus and Beauveria brongniartii and Metarhizium anisopliae, while termites reared in groups were highly resistant. Quantitative assays with an epifluoresent microscope revealed a significant difference in the number of conidia attachments among three entomopathogenic fungi. The conidia of B. brongniartii and P. fumosoroseus bound to termite cuticles more effectively than M. anisopliae conidia. Our results also suggested that self-grooming behavior is less effective, but mutual grooming is very effective in the removal of conidia from cuticles of their nestmates. Statistical analysis of removal rates indicated that conidia of P. fumosoroseus and B. brongniartii were removed more rapidly than M. anisopliae conidia from termite cuticles.

Alan R Lax - One of the best experts on this subject based on the ideXlab platform.

  • Screening of Multiple Potential Control Genes for use in Caste and Body Region Comparisons Using RT-qPCR in Coptotermes formosanus
    Sociobiology, 2014
    Co-Authors: Matthew R. Tarver, Dunhua Zhang, Christopher P. Mattison, Christopher B. Florane, Doug J. Hinchliffe, Alan R Lax
    Abstract:

    Formosan subterranean termites, Coptotermes formosanus , are a significant worldwide pest. Molecular gene expression is an important tool for understanding the physiology of organisms. The recent advancement of molecular tools for Coptotermes formosanus is leading to the advancement of the understanding of termite physiology. One of the first steps in analyzing gene expression is the normalization to constant reference genes. Stable reference genes that have constant expression across multiple treatments are important for accurately comparing target genes' expression. The objective of this investigation was to analyze and validate a set of potential reference genes including 8S rRNA; Glyceraldehyde 3-phosphate dehydrogenase ( Gadphd ); ribosomal protein L7 ( RPL ); β -actin (BA1) ; α -tubulin ( Atube ); α -actin ( Aactin ); and elongation factor ( Elong ) as standards for analysis of transcriptional changes in the termite Coptotermes formosanus , across two phenotypic castes, body regions, and colonies. We also compared the expression of hexamerin -1 and 2 using stable and unstable reference genes to demonstrate the importance of consistent control genes. Our results demonstrate that 18S and RPL can serve as reliable expression standards when comparing these different castes and body regions, and we show that C. formosanus Hex-1 and Hex-2 have expression patterns similar to that previously described in R. flavipes .

  • characterization of a new endogenous endo β 1 4 glucanase of formosan subterranean termite Coptotermes formosanus
    Insect Biochemistry and Molecular Biology, 2011
    Co-Authors: Dunhua Zhang, John M Bland, Alan R Lax, April B Allen
    Abstract:

    Abstract The present work characterized a new endogenous cellulase (endo-β-1,4-glucanase) gene, CfEG5, uncovered in the transcriptome of Formosan subterranean termite (Coptotermes formosanus). The full-length gene was cloned and sequenced. It is similar to the CfEG3a described earlier ( Zhang et al., 2009 ) but not likely an allelic variant. GenomeWalker™ DNA walking analysis indicated that there may be one copy of CfEG5 and two copies of CfEG3a in the termite genome. As with CfEG3a, the transcript of CfEG5 was detected predominantly in the salivary gland based on quantitative RT-PCR. Phylogenetic analysis of translated amino acid sequence showed that the CfEG5 is more related to CaEG, derived from an Australian subterranean termite (Coptotermes acinaciformis), than CfEG3a and other cellulases from Coptotermes formosanus, Reticulitermes speratus, or Reticulitermes flavipes. Recombinant CfEG5, produced in Escherichia coli, was active against filter-paper cellulose, resulting in mostly cellobiose and cellotriose, similar to the enzymatic and biochemical properties of CfEG3a. These findings would lead to further investigation of both the evolutionary origin of eukaryotic cellulase genes and the evolutionary relationship of termite species. The cellulose-degrading enzyme is applicable for bioconversion of wood to simple sugars and production of biofuels. The recombinant cellulase should also be useful for designing and screening of inhibitors for the development of target-specific and environment-friendly bio-termicides.

  • activity of 1 4 benzoquinones against formosan subterranean termites Coptotermes formosanus
    Journal of Agricultural and Food Chemistry, 2008
    Co-Authors: Kobaisy Mozaina, Alan R Lax, Charles L Cantrell, Amelia B Mims, Maria R Tellez, Weste L A Osbrink
    Abstract:

    A large number of naturally occurring and synthetic benzoquinones were evaluated for activity against the Formosan subterranean termite, Coptotermes formosanus, with potential use in termite control. Among these bioactive naturally occurring benzoquinones are 2-methyl-5-isopropyl-1,4-benzoquinone, 2-methoxy-6-pentyl-1,4-benzoquinone, 2,3-dimethoxy-5-methyl-6-(3-methyl-2-butenyl)-1,4-benzoquinone, 2,3-dimethoxy-5,6-dimethyl-1,4-benzoquinone, and 2,3-dichloro-5,6-dimethyl-1,4-benzoquinone. All five of these compounds demonstrated 100% mortality against C. formosanus by day 11 at a concentration of 1% (wt/wt) or less. In general, benzoquinones with one or two hydrophobic groups on the 5 and/or 6 positions of the quinone ring along with one or two group(s) on the opposite side of the ring, at the 2 and/or 3 position, led to high rates of mortality against C. formosanus. Quantitative structure-activity relationship (QSAR) studies showed no correlation between lipophilicity (calculated log P) and mortality for the entire group of nonhalogenated benzoquinones. A correlation was observed between C-6 chain length and day 3 percent mortality for 2,3-dimethoxy-5-methyl-6-substituted aliphatic benzoquinones where short chain lengths resulted in higher mortality.

  • plant derived natural products exhibiting activity against formosan subterranean termites Coptotermes formosanus
    Pest Management Science, 2006
    Co-Authors: Kumudini M. Meepagala, Weste L A Osbrink, George Sturtz, Alan R Lax
    Abstract:

    The Formosan subterranean termite, Coptotermes formosanus Shiraki, is among the most devastating termite pests. Natural products derived from plant extracts were tested in a discovery programme for effective, environmentally friendly termite control agents. Among the natural products tested, vulgarone B (isolated from Artemisia douglasiana Besser), apiol (isolated from Ligusticum hultenii (Fern.) Calder & Taylor) and cnicin (isolated from Centaurea maculosa Lam.) exhibited significantly higher mortalities than in untreated controls in laboratory bioassay. These compounds are present at high levels in their respective plant sources and also possess other biological activities such as phytotoxic and antifungal properties.

  • Plant‐derived natural products exhibiting activity against formosan subterranean termites (Coptotermes formosanus)
    Pest management science, 2006
    Co-Authors: Kumudini M. Meepagala, Weste L A Osbrink, George Sturtz, Alan R Lax
    Abstract:

    The Formosan subterranean termite, Coptotermes formosanus Shiraki, is among the most devastating termite pests. Natural products derived from plant extracts were tested in a discovery programme for effective, environmentally friendly termite control agents. Among the natural products tested, vulgarone B (isolated from Artemisia douglasiana Besser), apiol (isolated from Ligusticum hultenii (Fern.) Calder & Taylor) and cnicin (isolated from Centaurea maculosa Lam.) exhibited significantly higher mortalities than in untreated controls in laboratory bioassay. These compounds are present at high levels in their respective plant sources and also possess other biological activities such as phytotoxic and antifungal properties.