The Experts below are selected from a list of 4173 Experts worldwide ranked by ideXlab platform
Eugene M Fuzy - One of the best experts on this subject based on the ideXlab platform.
-
attraction of four entomopathogenic nematodes to four white Grub species
Journal of Invertebrate Pathology, 2008Co-Authors: Albrecht M Koppenhofer, Eugene M FuzyAbstract:To better understand the differences in the efficacy of entomopathogenic nematode species against white Grub species, we are studying the various steps of the infection process of entomopathogenic nematodes into different white Grub species using nematode species/strains with particular promise as white Grub control agents. In this study we compared the attraction of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), Steinernema glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and Heterorhabditis bacteriophora (GPS11 strain) to third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis, and late-instar greater wax moth, Galleria mellonella, larvae. Individual larvae were confined at the bottom of 5.5 cm vertical sand columns, nematodes added to the sand surface after 24 h, and nematodes extracted after another 24 h. Nematode attraction to hosts was strongly affected by nematode species but the effect of insect species varied with nematode species. S. glaseri had a high innate dispersal rate (i.e., in absence of insects) and was strongly attracted to insects without significant differences among insect species. S. scarabaei had a very low innate dispersal rate so that even a strong relative response to insects resulted in low absolute dispersal rates toward insects. S. scarabaei tended to be most attracted to G. mellonella and least attracted to C. borealis. H. zealandica had a high innate dispersal rate but only responded weakly to insects without significant differences among species. H. bacteriophora had limited innate dispersal and only weakly responded to insects with G. mellonella tending to be the most attractive and C. borealis the least attractive insect. It has to be noted that we cannot exclude that the use of different rearing hosts (A. orientalis and P. japonica larvae for S. scarabaei, G. mellonella larvae for the other nematodes) might have had an impact on the nematodes dispersal and relative attraction behavior. This study indicates that host attractiveness and nematode dispersal rates may contribute but do not play a major role in the variability in white Grub susceptibility and/or nematode virulence.
-
differences in penetration routes and establishment rates of four entomopathogenic nematode species into four white Grub species
Journal of Invertebrate Pathology, 2007Co-Authors: Albrecht M Koppenhofer, Parwinder S. Grewal, Eugene M FuzyAbstract:We compared the penetration of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), S. glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and H. bacteriophora (GPS11 strain) into third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis. When larvae were exposed to nematodes for 6-72 h larval mortality and nematode establishment rate and occasionally speed of kill often showed the same pattern within nematode-white Grub combinations. But no two nematodes or white Grub species had the same pattern for these observations for all white Grub or nematode species, respectively. Mortality, establishment, and speed of kill followed a similar pattern for H. zealandica, S. glaseri, and S. scarabaei, but there was no clear relationship for H. bacteriophora. Significant nematode establishment was only observed after at least 48 h exposure in most nematode-white Grub combinations. Faster establishment was observed only for H. zealandica in A. orientalis and R. majalis (after 24 h) and for S. scarabaei in P. japonica and R. majalis (after 12 h). Nematode establishment after 72 h in the different scarab species was generally low for S. glaseri (<1.5%) and H. bacteriophora (<3%), higher for H. zealandica (2-5%), and the highest for S. scarabaei (1-14%). However, in another experiment establishment was generally higher after 96h exposure. Nematode penetration sites were determined by comparing nematode establishment in larvae with mouth, anus, mouth+anus, or none sealed with glue. The trends for each nematode species were very similar in the different white Grub species. H. zealandica and H. bacteriophora showed excellent cuticular penetration ability but may also penetrate through mouth and/or anus. S. glaseri also penetrated through the cuticle but lower establishment in larvae with mouth or mouth+anus sealed suggested that the mouth is an important penetration site. S. scarabaei showed a preference for the mouth as a penetration site, but it showed some cuticular penetration ability and may also use the anus as a penetration site. The methodology used cannot exclude that cuticular penetration also included penetration through the spiracles. To fully understand the effect of nematode and white Grub species on nematode virulence, future studies will have to compare host immune response to the penetrating IJs and the role of the symbiotic bacteria in these interactions.
-
effect of white Grub developmental stage on susceptibility to entomopathogenic nematodes
Journal of Economic Entomology, 2004Co-Authors: Albrecht M Koppenhofer, Eugene M FuzyAbstract:The pathogenicity of the entomopathogenic nematodes Heterorhabditis bacteriophora Poinar and Steinernema scarabaei Stock & Koppenhofer against different developmental stages of the Japanese beetle, Popillia japonica Newman, and the oriental beetle, Anomala (=Exomala) orientalis Waterhouse, were studied under laboratory conditions. The efficacy of S. scarabaei did not differ between second and third instars in P. japonica or A. orientalis or between small (young) and large (older) third instars in A. orientalis. However, H. bacteriophora efficacy decreased from first over second to third instar and also from small third instars to large third instars in A. orientalis but did not differ significantly between P. japonica larval stages. Once A. orientalis third instars had purged their intestines in preparation for pupation, no significant mortality by S. scarabaei and H. bacteriophora was observed. In contrast, P. japonica susceptibility to both nematode species gradually decreased from stage to stage from actively feeding third instars to pupae. In two additional experiments, we found no difference in Steinernema glaseri (Steiner) susceptibility between second and third instars of A. orientalis but an increase in S. scarabaei susceptibility from the second to third instar of Asiatic garden beetle, Maladera castanea (Arrow). Our observations combined with those of previous studies with other nematode and white Grub species show that nematode efficacy against white Grub developmental stages varies with white Grub and nematodes species, and no generalization can be made.
-
effects of turfgrass endophytes clavicipitaceae ascomycetes on white Grub coleoptera scarabaeidae larval development and field populations
Environmental Entomology, 2003Co-Authors: Albrecht M Koppenhofer, Richard S Cowles, Eugene M FuzyAbstract:Abstract Previous observations on the effect of endophyte infection in turfgrass on white Grub development and natural incidence have been variable and contradictory. We reexamined these white Grub-endophyte interactions and expanded them to the previously not studied oriental beetle (Exomala [= Anomala] orientalis Waterhouse). Endophyte infection in strong creeping red fescue (Festuca rubra L. rubra) had no effect on survival and weight gain of neonate Japanese beetle (P. japonica Newman) and E. orientalis larvae in greenhouse pot experiments. In tall fescue (Festuca arundinacea Schreber) in greenhouse pot and in microplot field experiments, endophyte infection had no significant effect on survival and a weak negative effect on weight gain of P. japonica, but reduced E. orientalis survival without affecting its weight gain. In samples taken from tall fescue fields in October, the natural incidence of third instars was higher in endophytic than in nonendophytic turf in 3 of 4 yr. The effect was strongest ...
Albrecht M Koppenhofer - One of the best experts on this subject based on the ideXlab platform.
-
soil fertility amendments and white Grub populations of turf
Communications in Soil Science and Plant Analysis, 2014Co-Authors: Mary C Provancebowley, Albrecht M Koppenhofer, Joseph R HeckmanAbstract:Liming materials, calcium carbonate versus calcium magnesium silicate, were compared for effects on native white Grub (Coleoptera: Scarabaeidae) populations in a New Jersey lawn. A silt loam soil near Princeton, N.J., of mixed cool-season turf with an initial pH of 5.0 received applications of either liming material in January 2007 for a target pH of 6.5. Control plots received no lime application. Grub numbers were reduced by more than 50% in plots amended with either calcium magnesium silicate or calcium carbonate when compared with the controls. Both calcium magnesium silicate and calcium carbonate were similarly effective in achieving this benefit.
-
attraction of four entomopathogenic nematodes to four white Grub species
Journal of Invertebrate Pathology, 2008Co-Authors: Albrecht M Koppenhofer, Eugene M FuzyAbstract:To better understand the differences in the efficacy of entomopathogenic nematode species against white Grub species, we are studying the various steps of the infection process of entomopathogenic nematodes into different white Grub species using nematode species/strains with particular promise as white Grub control agents. In this study we compared the attraction of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), Steinernema glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and Heterorhabditis bacteriophora (GPS11 strain) to third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis, and late-instar greater wax moth, Galleria mellonella, larvae. Individual larvae were confined at the bottom of 5.5 cm vertical sand columns, nematodes added to the sand surface after 24 h, and nematodes extracted after another 24 h. Nematode attraction to hosts was strongly affected by nematode species but the effect of insect species varied with nematode species. S. glaseri had a high innate dispersal rate (i.e., in absence of insects) and was strongly attracted to insects without significant differences among insect species. S. scarabaei had a very low innate dispersal rate so that even a strong relative response to insects resulted in low absolute dispersal rates toward insects. S. scarabaei tended to be most attracted to G. mellonella and least attracted to C. borealis. H. zealandica had a high innate dispersal rate but only responded weakly to insects without significant differences among species. H. bacteriophora had limited innate dispersal and only weakly responded to insects with G. mellonella tending to be the most attractive and C. borealis the least attractive insect. It has to be noted that we cannot exclude that the use of different rearing hosts (A. orientalis and P. japonica larvae for S. scarabaei, G. mellonella larvae for the other nematodes) might have had an impact on the nematodes dispersal and relative attraction behavior. This study indicates that host attractiveness and nematode dispersal rates may contribute but do not play a major role in the variability in white Grub susceptibility and/or nematode virulence.
-
differences in penetration routes and establishment rates of four entomopathogenic nematode species into four white Grub species
Journal of Invertebrate Pathology, 2007Co-Authors: Albrecht M Koppenhofer, Parwinder S. Grewal, Eugene M FuzyAbstract:We compared the penetration of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), S. glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and H. bacteriophora (GPS11 strain) into third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis. When larvae were exposed to nematodes for 6-72 h larval mortality and nematode establishment rate and occasionally speed of kill often showed the same pattern within nematode-white Grub combinations. But no two nematodes or white Grub species had the same pattern for these observations for all white Grub or nematode species, respectively. Mortality, establishment, and speed of kill followed a similar pattern for H. zealandica, S. glaseri, and S. scarabaei, but there was no clear relationship for H. bacteriophora. Significant nematode establishment was only observed after at least 48 h exposure in most nematode-white Grub combinations. Faster establishment was observed only for H. zealandica in A. orientalis and R. majalis (after 24 h) and for S. scarabaei in P. japonica and R. majalis (after 12 h). Nematode establishment after 72 h in the different scarab species was generally low for S. glaseri (<1.5%) and H. bacteriophora (<3%), higher for H. zealandica (2-5%), and the highest for S. scarabaei (1-14%). However, in another experiment establishment was generally higher after 96h exposure. Nematode penetration sites were determined by comparing nematode establishment in larvae with mouth, anus, mouth+anus, or none sealed with glue. The trends for each nematode species were very similar in the different white Grub species. H. zealandica and H. bacteriophora showed excellent cuticular penetration ability but may also penetrate through mouth and/or anus. S. glaseri also penetrated through the cuticle but lower establishment in larvae with mouth or mouth+anus sealed suggested that the mouth is an important penetration site. S. scarabaei showed a preference for the mouth as a penetration site, but it showed some cuticular penetration ability and may also use the anus as a penetration site. The methodology used cannot exclude that cuticular penetration also included penetration through the spiracles. To fully understand the effect of nematode and white Grub species on nematode virulence, future studies will have to compare host immune response to the penetrating IJs and the role of the symbiotic bacteria in these interactions.
-
effect of white Grub developmental stage on susceptibility to entomopathogenic nematodes
Journal of Economic Entomology, 2004Co-Authors: Albrecht M Koppenhofer, Eugene M FuzyAbstract:The pathogenicity of the entomopathogenic nematodes Heterorhabditis bacteriophora Poinar and Steinernema scarabaei Stock & Koppenhofer against different developmental stages of the Japanese beetle, Popillia japonica Newman, and the oriental beetle, Anomala (=Exomala) orientalis Waterhouse, were studied under laboratory conditions. The efficacy of S. scarabaei did not differ between second and third instars in P. japonica or A. orientalis or between small (young) and large (older) third instars in A. orientalis. However, H. bacteriophora efficacy decreased from first over second to third instar and also from small third instars to large third instars in A. orientalis but did not differ significantly between P. japonica larval stages. Once A. orientalis third instars had purged their intestines in preparation for pupation, no significant mortality by S. scarabaei and H. bacteriophora was observed. In contrast, P. japonica susceptibility to both nematode species gradually decreased from stage to stage from actively feeding third instars to pupae. In two additional experiments, we found no difference in Steinernema glaseri (Steiner) susceptibility between second and third instars of A. orientalis but an increase in S. scarabaei susceptibility from the second to third instar of Asiatic garden beetle, Maladera castanea (Arrow). Our observations combined with those of previous studies with other nematode and white Grub species show that nematode efficacy against white Grub developmental stages varies with white Grub and nematodes species, and no generalization can be made.
-
effects of turfgrass endophytes clavicipitaceae ascomycetes on white Grub coleoptera scarabaeidae larval development and field populations
Environmental Entomology, 2003Co-Authors: Albrecht M Koppenhofer, Richard S Cowles, Eugene M FuzyAbstract:Abstract Previous observations on the effect of endophyte infection in turfgrass on white Grub development and natural incidence have been variable and contradictory. We reexamined these white Grub-endophyte interactions and expanded them to the previously not studied oriental beetle (Exomala [= Anomala] orientalis Waterhouse). Endophyte infection in strong creeping red fescue (Festuca rubra L. rubra) had no effect on survival and weight gain of neonate Japanese beetle (P. japonica Newman) and E. orientalis larvae in greenhouse pot experiments. In tall fescue (Festuca arundinacea Schreber) in greenhouse pot and in microplot field experiments, endophyte infection had no significant effect on survival and a weak negative effect on weight gain of P. japonica, but reduced E. orientalis survival without affecting its weight gain. In samples taken from tall fescue fields in October, the natural incidence of third instars was higher in endophytic than in nonendophytic turf in 3 of 4 yr. The effect was strongest ...
T. A. Jackson - One of the best experts on this subject based on the ideXlab platform.
-
isolation and enumeration of serratia entomophila a bacterial pathogen of the new zealand grass Grub costelytra zealandica
Journal of Applied Microbiology, 1993Co-Authors: Maureen Ocallaghan, T. A. JacksonAbstract:Several agar media were tested for their use in a selective isolation and identification scheme for Serratia entomophila, a bacterium causing amber disease of the New Zealand grass Grub, Costelytra zealandica (White). Soil dilutions were plated on caprylate thallous agar (CTA), selective for Serratia spp. Most strains of Ser. entomophila grew well on CTA; the mean efficiency of colony formation on CTA was 94 ± 3% of that on a non-selective medium. The identity of colonies growing on CTA was determined on the basis of their growth reactions on DNase-toluidine blue agar, adonitol agar and itaconate agar. Serratia entomophila could be distinguished from other Serratia spp. found in New Zealand soils, in particular Ser. proteamaculans, another causal agent of amber disease of grass Grub. The identification scheme allowed the selective recovery of Ser. entomophila from field soils containing a diverse microflora.
Peter G. Mcgregor - One of the best experts on this subject based on the ideXlab platform.
-
Gut pH and amylase and protease activity in larvae of the New Zealand grass Grub (Costelytra zealandica; Coleoptera: Scarabaeidae) as a basis for selecting inhibitors
Insect Biochemistry and Molecular Biology, 1996Co-Authors: David R. Biggs, Peter G. McgregorAbstract:Abstract Using a purpose-built antimony silver-silver chloride microelectrode we determined the pH of gut contents of field-collected third instars of the pasture pest Costelytra zealandica (White) (Coleoptera: Scarabaeidae) (grass Grub), pH was 8.4 ± 0.69 (mean ± SD) (n = 7) in the anterior pre-caecal portion of the midgut; it rose to 10.8 ±1.28 (n = 19) in the anterior part of the remaining midgut, and 10.9 ± 0.95 (n = 17) in the middle of the midgut, before dropping again to 9.3 ± 0.68 (n = 19) at the posterior end of the midgut. The pH was 8.2 ± 0.35 (n = 17) in the large hindgut. These data correct a previous suggestion that pH was approximately neutral in the grass Grub gut. The data were then used to determine the functional localization of amylase and protease activities within the gut, by conducting assays at physiological pH values rather than the pH optima of the enzymes. Highest amylase activity was in the pre-caecal portion of the midgut; the hindgut showed relatively little activity. No activity was detected in the main part of the midgut because of that region's high pH. Protease activity was detected throughout the midgut. The pH data were also used to select putative inhibitors of the grass Grub amylase. At pH 8.5 (the pH of the pre-caecal midgut), inhibitors from wheat and other Gramineae were active but a purified inhibitor from kidney bean showed no activity. These results indicate the importance of determining gut pH in studies of insect digestive enzymes.
Trevor A Jackson - One of the best experts on this subject based on the ideXlab platform.
-
autochthonous bacterial flora indicated by pcr dgge of 16s rrna gene fragments from the alimentary tract of costelytra zealandica coleoptera scarabaeidae
Journal of Applied Microbiology, 2008Co-Authors: Hongyu Zhang, Trevor A JacksonAbstract:Aims: To locate and identify putative autochthonous bacteria within the grass Grub gut that may have a role in symbiosis. Methods and Results: Polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) fingerprinting was used to investigate bacterial diversity in the grass Grub larval gut. The microbial community profiles from five geographically distinct populations were compared and the influence of feeding was analysed. Bacterial community in the midgut was highly variable between locations and was affected by feeding. The hindgut contained a more diverse but stable bacterial community that was less affected by external conditions. Forty-seven distinct DGGE bands, representing different bacterial genotypes, could be distinguished from all samples, with 34 different bands occurring in the hindgut. The 22 most common bands were isolated and DNA was sequenced. Sequence analysis revealed that most bacteria (16/22) were affiliated to the Clostridiales with the predominant bacteria affiliated to the genus Clostridium. The remaining bacteria were aligned to the Betaproteobacteria, Deltaproteobacteria and Bacteroidetes. Conclusions: The grass Grub larva has an autochthonous microflora with predominance of Clostridium spp. in the hindgut. Significance and Impact of the Study: Occurrence of an autocthonous microflora in the grass Grub hindgut suggests a symbiotic relationship which could help explain the ability of larval scarabs to feed on recalcitrant organic matter.
-
carrot seed coating with bacteria for seedling protection from grass Grub damage
New Zealand Plant Protection, 2005Co-Authors: David A Wright, J. Swaminathan, M Blaser, Trevor A JacksonAbstract:Carrot seedlings are susceptible to damage from grass Grub larvae. The biological control bacterium, Serratia entomophila, was applied to the surface of carrot seeds via pelleting or as a biopolymer seed coating and the activity against grass Grubs determined in pot trials. Seedling mortality caused by grass Grub larvae was signifi cantly reduced (P<0.05) in two trials from 88 and 64% in untreated pots to 26 and 13% in pots containing pelleted seed and 7 and 16% in pots containing biopolymer-coated seed. Shelf life studies showed formulations were stable at 4°C for at least eight weeks and for two weeks at 20°C, after which cell viability decreased over time. Bioassay results showed little difference between the two treatments, despite a higher concentration of bacteria on the biopolymer-coated than the pelleted seeds. The potential of seed coating as a delivery mechanism for biocontrol agents has been demonstrated and future possibilities are discussed.
-
establishment of serratia entomophila after application of a new formulation for grass Grub control
New Zealand Plant Protection, 2004Co-Authors: R. J. Townsend, Maureen Ocallaghan, C. M. Ferguson, J. R. Proffitt, M. W. A. Slay, J. Swaminathan, S. Day, Trevor A Jackson, E M Gerard, V W JohnsonAbstract:The bacterium Serratia entomophila is a naturally occurring pathogen causing amber disease of the New Zealand grass Grub (Costelytra zealandica). A novel granular formulation of S. entomophila, Bioshield™, was applied to 18 pasture sites in a large-scale programme to demonstrate efficacy against grass Grub. No significant difficulties were encountered in application of the granules through conventional machinery. There were high populations of the applied bacteria in soil within the first week of application, and within 6 weeks of application there was an average of 3 x 10 4 viable S. entomophila, of the applied strain, per gram of soil. This resulted in a significant (P<0.05) 20% increase in the incidence of amber disease in the treated grass Grub populations compared to untreated populations. Successful establishment of the bacteria in the soil and target population following Bioshield™ granule application was demonstrated on a wide range of sites under various farming conditions.
