Hao, Y. u., Gouge, D. H., & Shapiro-Ilan, D. I. (2010). A novel strain of Steinernema riobrave (Rhabditida: Steinernematidae) possesses superior virulence to subterranean termites (Isoptera: Rhinotermitidae). Journal of Nematology, 42(2), 91-95.
PMID: 22736844;PMCID: PMC3380470;Abstract:
Subterranean termites are major global pests of wood structures and wood products. Among the most economically important subterranean termite species in the US are Heterotermes aureus, Reticulitermes flavipes, and Coptotermes formosanus. In prior studies, the entomopathogenic nematode, Steinernema riobrave strain 355, exhibited a high level of virulence to H. aureus compared with other nematode species. However, S. riobrave 355 was reported to be poorly or only moderately virulent to It flavipes and C. formosanus, respectively. We hypothesized that other strains of S. riobrave may possess a high level of virulence to all three termite species. Under laboratory conditions we compared three novel strains of 5. riobrave (3-8b, 7-12, and TP) with the 355 strain for virulence to H. aureus, R. flavipes, and C. formosanus workers. H. aureus was very susceptible to all the S. riobrave strains, and termites in all nematode treatments were dead after 4 d. The TP strain of S. riobrave caused greater mortality in R. flavipes and C. formosanus compared to the other nematode strains. Specifically, the TP strain caused 75% and 91% mortality in R. flavipes and C. formosanus, respectively, which was more than 300% and 70% higher than the mortality caused by other strains. Additional studies are warranted to determine the ability of S. riobrave (TP) to control the targeted termite species under field conditions. © The Society of Nematologists 2010.
Cui, J., Li, S., Spurgeon, D. W., Jia, W., Lu, Y., & Gouge, D. H. (2016). Flight capacity of Sitophilus zeamais (Coleoptera: Curculionidae) in relation to gender and temperature. Southwestern Entomologist, 41(3), 667-674. doi:http://dx.doi.org/10.3958/059.041.0309
Gouge, D. H., Li, S., Nair, S., Pier, N., & Sumner, C. (2016). Mosquitoes and the Great Outdoors. Journal of Environmental Management Arizona, 5-6.
Gouge, D. H., Smith, K. A., Lee, L. L., & Henneberry, T. J. (2000). Effect of soil depth and moisture on the vertical distribution of Steinernema riobrave (Nematoda: Steinernematidae). Journal of Nematology, 32(2), 223-228.
PMID: 19270970;PMCID: PMC2620435;Abstract:
The effect of soil moisture on the distribution of Steinernema riobrave in a sand column was determined. Larvae of Pectinophora gossypiella were used to detect S. riobrave infective juveniles (IJ) in each 2.5-cm section of 30-cm-long soil columns. Soil moisture was determined for each section and related to the numbers of nematodes recovered from infected insect baits. Infective juveniles of S. riobrave applied on the sand column surface showed some degree of positive geotaxis. IJ in soil columns with a consistent moisture gradient grouped in the upper 12.7 cm within a water potential range of -40 to -0.0055 MPa (2% to 14% moisture). Nematodes in sand columns that were gradually dehydrating moved down the soil column, aggregating on the 28th day between 15-23 cm in depth. Nematode redistribution over time allowed IJ to remain within a water potential range of -0.1 to -0.012 MPa (5.2% to 9.5% moisture).
Gouge, D. H., Gouge, D. H., Snyder, J. L., & Snyder, J. L. (2006). Temporal association of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) and bacteria. Journal of Invertebrate Pathology, 91(3), 147-157.
PMID: 16448667;Abstract:
Galleria mellonella L. larvae were infected with three species (seven strains) of Steinernema spp. or three species (three strains) of Heterorhabditis spp. Infected larvae were incubated at 22, 27, and 32°C. Larvae were dorsally dissected every 6 h over a 48-h period. Hemolymph was collected and streaked on tryptic soy agar plates. Several non-symbiotic bacterial species were identified from infected insect cadavers: Enterobacter gergoviae, Vibrio spp., Pseudomonas fluorescens type C, Serratia marcescens, Citrobacter freundii, and Serratia proteomaculans. At 18-24 h incubation, the nematode-associated symbiont occurred almost exclusively. Bacterial associates generally appeared outside the 18-24 h window. Infective juveniles of Steinernema feltiae (Filipjev) (27), Steinernema riobrave Cabanillas, Poinar, and Raulston (Oscar), or Steinernema carpocapsae (Weiser) (Kapow) were left untreated, or surface sterilized using thimerosal, then pipetted under sterile conditions onto tryptic soy agar plates. Several additional species of associated bacteria were identified using this method compared with the less extensive range of species isolated from infected G. mellonella. There was no difference in bacterial species identified from non-sterile or surface sterilized nematodes, suggesting that the bacteria identified originated from either inside the nematode or between second and third stage juvenile cuticles. Infective juveniles of S. feltiae (Cowles), S. carpocapsae (Cowles), and H. bacteriophora Poinar (Cowles) were isolated from field samples. Nematodes were surface-sterilized using sodium hypochlorite, mixed with G. mellonella hemolymph, and pipetted onto Biolog BUG (with blood) agar. Only the relevant symbionts were isolated from the limited number of samples available. The nematodes were then cultured in the laboratory for 14 months (sub-cultured in G. mellonella 7-times). Other Enterobacteriaceae could then be isolated from the steinernematid nematodes including S. marcescens, Salmonella sp., and E. gergoviae, indicating the ability of the nematodes to associate with other bacteria in laboratory culture. © 2005 Elsevier Inc. All rights reserved.
