Entity

Time filter

Source Type

Ball Ground, GA, United States

Shapiro-Ilan D.I.,U.S. Department of Agriculture | Morales-Ramos J.A.,U.S. Department of Agriculture | Rojas M.G.,U.S. Department of Agriculture | Tedders W.L.,Southeastern Insectaries Inc.
Journal of Invertebrate Pathology | Year: 2010

An alternative approach to applying entomopathogenic nematodes entails the distribution of nematodes in their infected insect hosts. Protection of the infected host from rupturing, and improving ease of handling, may be necessary to facilitate application. In this study our objective was to test the potential of a new method of formulating the infected hosts, i.e., enclosing the infected host in masking tape. Tenebrio molitor L. cadavers infected with Heterorhabditis indica Poinar, Karunakar and David or Steinernema carpocapsae (Weiser) were wrapped in tape using an automatic packaging machine; the machine was developed to reduce labor and to standardize the final product. The effects of the tape formulation on the ability to protect the cadavers from mechanical damage, nematode yield, and pest control efficacy were tested. After exposure to mechanical agitation at 7-d-post-infection, S. carpocapsae cadavers in tape were more resistant to rupture than cadavers without tape, yet H. indica cadavers 7-d-post-infection were not affected by mechanical agitation (with or without tape), nor was either nematode affected when 4-d-old cadavers were tested. Experiments indicated that infective juvenile yield was not affected by the tape formulation. Laboratory experiments were conducted measuring survival of the root weevil, Diaprepes abbreviatus (L.), or the small hive beetle, Aethina tumida Murray, after the application of two H. indica-infected hosts with or without tape per 15 cm pot (filled with soil). A greenhouse experiment was also conducted in a similar manner measuring survival of D. abbreviatus. In all experiments, both the tape and no-tape treatments caused significant reductions in insect survival relative to the control, and no differences were detected between the nematode treatments. Fifteen days post-application, the infected host treatments caused up to 78% control in A. tumida, 91% control in D. abbreviatus in the lab, and 75% in the greenhouse. These results indicate potential for using the tape-formulation approach for applying nematode infected hosts. Source


Shapiro-Ilan D.,U.S. Department of Agriculture | Rojas M.G.,U.S. Department of Agriculture | Morales-Ramos J.A.,U.S. Department of Agriculture | Tedders W.L.,Southeastern Insectaries Inc.
Journal of Nematology | Year: 2012

To facilitate improved in vivo culture of entomopathogenic nematodes, production of both insect hosts and nematodes should be optimized for maximum fitness, quality, and cost efficiency. In previous studies, we developed an improved diet for Tenebrio molitor, a host that is used for in vivo nematode production, and we demonstrated that single insect diet components (e.g., lipids and proteins) can have a positive or negative impact on entomopathogenic nematode fitness and quality. In this study, we tested components of our improved T. molitor diet (lipids, cholesterol, and a salt [MnSO4]) alone and in combination for effects on host susceptibility and reproductive capacity of Heterorhabditis indica and Steinernema carpocapsae. Our results indicated that moderate levels of lipids (10%) increased host susceptibility to S. carpocapsae but did not affect H. indica, whereas cholesterol and MnSO 4 increased host susceptibility to H. indica but not S. carpocapsae. The combined T. molitor diet (improved for increased insect growth) increased host susceptibility to S. carpocapsae and had a neutral effect on H. indica; interactions among single diet ingredients were observed. No effects of insect host diet were detected on the reproductive capacity of either nematode species in T. molitor. Subsequently, progeny infective juveniles, derived from nematodes grown in T. molitor that were fed diets with varying nutritive components were tested for virulence to and reproduction capacity in the target pest Diaprepes abbreviatus. The progeny nematodes produced from differing T. molitor diet treatments did not differ in virulence except H. indica derived from a diet that lacked cholesterol or MnS04 (but contained lipids) did not cause significant D. abbreviatus suppression relative to the water control. We conclude that the improved insect host diet is compatible with production of H. indica and S. carpocapsae, and increases host susceptibility in S. carpocapsae. Furthermore, in a general sense, our results indicate host diets can be optimized for improved in vivo entomopathogenic nematode production efficiency. This is the first report of an insect diet that was optimized for both host and entomopathogenic nematode production. Additionally, our study indicates that host diet may impact broader aspects of entomopathogenic nematode ecology and pest control efficacy. © The Society of Nematologists 2012. Source


Morales-Ramos J.A.,U.S. Department of Agriculture | Rojas M.G.,U.S. Department of Agriculture | Shapiro-Ilan D.I.,U.S. Department of Agriculture | Tedders W.L.,Southeastern Insectaries Inc.
Environmental Entomology | Year: 2011

We studied the ability of Tenebrio molitor L. (Coleoptera: Tenebrionidae) to self-select optimal ratios of two dietary components to approach nutritional balance and maximum fitness. Relative consumption of wheat bran and dry potato flakes was determined among larvae feeding on four different ratios of these components (10, 20, 30, and 40% potato). Groups of early instars were provided with a measured amount of food and the consumption of each diet component was measured at the end of 4 wk and again 3 wk later. Consumption of diet components by T. molitor larvae deviated significantly from expected ratios indicating nonrandom self-selection. Mean percentages of dry potato consumed were 11.98, 19.16, 19.02, and 19.27% and 11.89, 20.48, 24.67, and 25.97% during the first and second experimental periods for diets with 10, 20, 30, and 40% potato, respectively. Life table analysis was used to determine the fitness of T. molitor developing in the four diet mixtures in a no-choice experiment. The diets were compared among each other and a control diet of wheat bran only. Doubling time was significantly shorter in groups consuming 10 and 20% potato than the control and longer in groups feeding on 30 and 40% potato. The self-selected ratios of the two diet components approached 20% potato, which was the best ratio for development and second best for population growth. Our findings show dietary self-selection behavior in T. molitor larvae, and these findings may lead to new methods for optimizing dietary supplements for T. molitor. © 2011 Entomological Society of America. Source


Morales-Ramos J.A.,U.S. Department of Agriculture | Rojas M.G.,U.S. Department of Agriculture | Shapiro-Llan D.I.,U.S. Department of Agriculture | Tedders W.L.,U.S. Department of Agriculture | Tedders W.L.,Southeastern Insectaries Inc.
Journal of Entomological Science | Year: 2013

A new method to refine existing dietary supplements for improving production of the yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae), was tested. Self-selected ratios of 6 dietary ingredients by T. molitor larvae were used to produce a dietary supplement. This supplement was compared with existing supplement formulations mixed with wheat bran at 1:4 ratio and a control consisting of wheat bran alone for food utilization efficiency, larval growth, development time, immature survival, and fecundity. Ingredients of dietary supplements included dry potato as a source of carbohydrate; dry egg white and soy protein as a source of protein and; peanut, canola, and salmon oil as a source of lipid. A supplement consisting of dry potato alone significantly improved food utilization, growth, development time, survival, and fecundity compared with the wheat bran-only control group. The addition of protein to the supplement significantly shortened development time and improved food conversion efficiency and fecundity compared with the supplement with potato alone. The addition of lipid did not provide any significant improvements. The supplement derived from self-selected ratios of the basic ingredients provided a significant increase in fecundity compared with previously developed supplements and the control. Self-selected ratios of the basic ingredients by T. molitor larvae had an effect on the adult stage that resulted in significantly higher progeny production. Source


Spiewok S.,Martin Luther University of Halle Wittenberg | Delaplane K.S.,University of Georgia | Buchholz S.,Martin Luther University of Halle Wittenberg | Neumann P.,Agroscope Liebefeld Posieux Research Station | And 3 more authors.
Journal of Economic Entomology | Year: 2010

In this study, we evaluated the potential use of entomopathogenic nematodes as a control for the beetle Aethina tumida Murray (Coleoptera: Nitidulidae). In particular, we conducted 1) four screening bioassays to determine nematode (seven species, 10 total strains tested) and application level effects on A. tumida larvae and pupae, 2) a generational persistence bioassay to determine whether single inoculations with nematodes would control multiple generations of A. tumida larvae in treated soil, and 3) a field bioassay to determine whether the nematodes would remain efficacious in the field. In the screening bioassays, nematode efficacy varied significantly by tested nematode and the infective juvenile (IJ) level at which they were applied. Although nematode virulence was moderate in screening bioassays 1-3 (0-68% A. tumida mortality), A. tumida mortality approached higher levels in screening bioassay 4 (nearly 100% after 39 d) that suggest suitable applicability of some of the test nematodes as field controls for A. tumida. In the generational persistence bioassay, Steinernema riobrave Cabanillas, Poinar & Raulston 712 strain and Heterorhabditis indica Poinar, Karunaka & David provided adequate A. tumida control for 19 wk after a single soil inoculation (76-94% mortality in A. tumida pupae). In the field bioassay, the same two nematode species also showed high virulence toward pupating A. tumida (88-100%) mortality. Our data suggest that nematode use may be an integral component of an integrated pest management scheme aimed at reducing A. tumida populations in bee colonies to tolerable levels. © 2010 Entomological Society of America. Source

Discover hidden collaborations