- Introduction
- Taxonomy
- Occurrence
- New Species
- Distribution
- Biology
- Dispersal
- Virulence/Host range/Infectivity
- Temperature
- Survival and Persistence
- Tritrophic Effects
- Compatibility
- Genetic Improvement
- Bioefficiency
- Mass Production
- Formulation and Storage
- Application
- Abiotic Factors
- Biotic Factors
- Integration in IPM
- Bioafety
- Nontarget Effects
- Commercial Products
- Quality
- Techniques
- Chromosomes
- Associated Bacteria
Techniques
Abstracts
1. Jiang-H; Yang-HW; Zhang-NX. 1995. An improvement of the centrifugal flotation method to recover entomopathogenic nematodes from soil. Chinese-Journal-of-Biological-Control. 11:1, 13-16; 3 ref.
AB: An improvement of Saunders' centrifugal flotation method to recover nematodes from soil is described. The nematodes in the supernatant liquid from the first spinning were counted. The average recovery rate of Steinernema carpocapsae increased from 32.2% (by Saunders' method) to 60.2% (by the improved method). No noticeable adverse effect on nematode survival and infectivity to Carposina nipponensis larvae was observed after centrifugal treatments, but the proportion of nematode with cuticles was slightly reduced. The same recovery rate was obtained by using a salt solution (200 g/litre) instead of sucrose solution (454 g/litre) as flotation agent. The cost of centrifugal procedure by the improved method was reduced.
ARGENTINA-TECHNIQUE
2. Doucet-MMA-de; Giayetto-AL; Bertolotti-MA; Doucet-MMA-de; Giayetto-AL; Bertolotti-MA; de-Doucet-MMA. 1998 Efficiency of the rapid technique to detect entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in soil. Nematologia-Mediterranea. 26:2, 139-143; 11 ref. Eficiencia de la tecnica rapida para deteccion de nematodos entomopatogenos (STEINERNEMAtidae y Heterorhabditidae) en suelo. Laboratorio de Nematologia, Centro de Zoologia Aplicada. Universidad Nacional de Cordoba, Casilla de Correo 122. 5000 Cordoba, Argentina.
AB: The efficiency of this rapid technique was evaluated to determine how many nematodes can be recovered when a single species is present in the soil and whether it permits the detection of more than one species. The soil was artificially infested with infective juveniles belonging to Heterorhabditis bacteriophora and/or Steinernema glaseri. The nematodes were recovered and quantified by manual dissection or enzymatic digestion. The use of the technique allows the detection of all the active infective juveniles when a single species is present, and indicates the presence of 2 species in the same sample with the results being obtained within 48 h.
3. Grenier-E; Laumond-C; Abad-P. 1995. Characterization of a species-specific satellite DNA from the entomopathogenic nematode Steinernema carpocapsae. Molecular-and-Biochemical-Parasitology, 69:1, 93-100.
AB: An HaeIII satellite DNA family was cloned from S. carpocapsae. This repeated sequence appears to be an unusually abundant satellite DNA, since it constitutes about 62% of the S. carpocapsae genome. The nucleotide sequences of 13 monomers were determined. This satellite DNA family is represented by 2 sub-families: one with monomeric units of 170bp and the other with monomeric units of 182bp. These monomers are quite homogeneous in sequence, showing an average inter monomer variability of 6% from the consensus sequence. These results suggest that some homogenizing mechanism is acting to maintain the homogeneity of this satellite DNA. After hybridization with the genomic DNA of several other Steinernema species, this DNA sequence appears to be specific to the S. carpocapsae genome. Therefore, the species specificity and the high copy number of the HaeIII satellite DNA sequence should provide a rapid and powerful tool which could contribute to the identification of Steinernema species.
4. Doucet-MMA-de; Giayetto-AL; Bertolotti-MA; Doucet-MMA-de; Giayetto-AL; Bertolotti-MA; de-Doucet-MMA. 1998. Efficiency of the rapid technique to detect entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in soil. Laboratorio de Nematologia, Centro de Zoologia Aplicada. Universidad Nacional de Cordoba, Casilla de Correo 122. 5000 Cordoba, Argentina.
AB: The efficiency of this rapid technique was evaluated to determine how many nematodes can be recovered when a single species is present in the soil and whether it permits the detection of more than one species. The soil was artificially infested with infective juveniles belonging to Heterorhabditis bacteriophora and/or Steinernema glaseri. The nematodes were recovered and quantified by manual dissection or enzymatic digestion. The use of the technique allows the detection of all the active infective juveniles when a single species is present, and indicates the presence of 2 species in the same sample with the results being obtained within 48 h.
5. Zhang-SG; Yang-HW. 1988. Improvement of the techniques for maintaining bacterial symbionts of entomopathogenic nematodes on agar slant. Chinese-Journal-Of-Biological-Control, 4:3, 111-113.
AB:Fourteen bacterial symbionts, whose nematode hosts were Steinernema glaseri [Neoaplectana glaseri], S. feltiae [N. feltiae], S. bibionis [N. bibionis], S. affinis [N. affinis], and Heterorhabditis heliothidis, were tested for the duration of maintenance on nutrient agar slant at 10°C. The results demonstrated that the symbionts kept their primary form and antibiotic activities for at least 6 months, enabling subculture of the bacteria every 6 months, instead of monthly as when using the conventional subculture method on YS agar at 12°C.
CHINA- STAINING
6. Yang-HW; Jian-H. 1988 Labelling living entomopathogenic nematodes with stains. Chinese-Journal-of-Biological-Control. 4:2, 59-61; 3 ref. Biol. Control Lab., Chinese Acad. Agric. Sci., Beijing, China.
AB: Different stages of Steinernema feltiae [Neoaplectana carpocapsae], S. bibionis [N. bibionis] and S. glaseri [N. glaseri] were stained with one of 7 biological stains added to the media at 0.5%. Nematodes stained with Sudan II and Sudan III showed red colour in their intestinal contents and fat bodies, and were easily distinguishable. The colour of the stained nematodes lasted until they penetrated insect hosts. The stains had no adverse effect on their fecundity or infectivity. It is concluded that this method is effective for identifying and tracing the activities of nematodes used in laboratory experiments.
7. Fitters-PFL; Meijer-EMJ; Wright-DJ; Griffin-CT. 1997. Estimation of lipid reserves in unstained living and dead nematodes by image analysis. Journal-of-Nematology. 29:2, 160-167; 22 ref.
AB: Optical density per unit area (OD per area) of infective juveniles of Steinernema carpocapsae (All) and two Heterorhabditis isolates (UK211 and HF85) was measured with an image analysis system and compared with neutral lipid levels obtained by Oil Red O staining. Optical density (OD) measurements were compared with triglyceride levels of UK211 and HF85. Good correlations between OD per area and neutral lipids (0.90) and between OD and triglycerides (0.87) were found. Thus, OD reflects lipid levels and can be used as an indicator of lipid reserves in these nematodes. Heat-killing of nematodes had no significant effect on OD measurements, but length increased significantly. Storage in a triethanolamine in formaldehyde solution decreased the OD and OD/area by about 5% to 8%. An additional advantage of the image analysis method described is that repeated measurements can be performed on live nematodes.
8. Smith-BS; Hodgson-Smith-A; Popiel-I; Minter-DM; James-ER. 1990. Cryopreservation of the entomogenous nematode parasite Steinernema feltiae (= Neoaplectana carpocapsae). Cryobiology. 27:3, 319-327.
AB: Cryopreservation studies were conducted with the J1 juvenile and 3rd-stage infective juvenile (IJ) larvae of Steinernema feltiae (Neoaplectana feltiae). The main parameters evaluated were: tolerance of the organisms to the cryoprotectants methanol, ethanediol, glycerol and dimethyl sulphoxide; the incubation temperature and exposure period in cryoprotectant; and slow cooling (circa 10C/min) vs. rapid cooling (circa 5-100C/min). The J1 stage was sensitive to all cryoprotectants at >20% (v/v). This sensitivity increased at 22 and 370C. Exsheathed IJ stage organisms tolerated exposure to 50% (v/v) ethanediol or ME2SO and 60% (v/v) methanol or glycerol. A proportion (3.4%) of J1s preincubated in 20% (v/v) methanol for 10 min at 0°C survived slow cooling to -35°C followed by a plunge into liquid nitrogen. Preincubation in 60% (v/v) ME2SO for 45 sec at 0°C followed by rapid cooling yielded a higher proportion (12.3%) of surviving J1s. The infective IJ stage only survived rapid cooling. Preincubation for 20 min at 0°C in either 60% (v/v) methanol or 45% glycerol, followed by rapid cooling at 5-100C/min, yielded 30-34% viable IJs following thawing. These larvae were capable of further growth and development in vitro. The results suggest that the organisms are vitrified during the rapid cooling step. For routine maintenance of strains of N. feltiae and related general it is preferable to use the IJ stage.
9. Lee-SeungHwa; Kim-YongGyun; Han-SangChan; Lee-SH; Kim-YG; Han-SC. 2000. Cryopreservation of the entomopathogenic nematode, Steinernema carpocapsae Weiser. Korean-Journal-of-Applied-Entomology. 39:3, 149-152; 18 ref.
Cryopreservation of infective juveniles of Steinernema carpocapsae Weiser, was conducted at -190°C liquid nitrogen and its efficacy was analysed on nematode survival and pathogenicity with glycerol pretreatments and storage periods. Infective juveniles were pre-treated before being frozen by incubating the nematodes in 22% glycerol for each of 6, 12, and 24 h, followed by 70% methanol at 0°C for 10 minutes. Just after glycerol and methanol incubations, subsamples of the nematodes were resuspended in 0.85% saline and maintained during 24h for viability determination. Different glycerol incubation periods significantly affected the nematode susceptibility to methanol infiltration. Six hour incubation in glycerol resulted in much less nematode survival than did 12 h or 24 h incubation. About 70% of the infective juveniles frozen at -190°C for 5 months, preincubat-ed in glycerol at least for 12h, were able to survive after being resuspended in 30°C saline. They did not show any change in their pathogenicity during cryopreservation. These results suggest an improved technique for long-term storage of the entomopathogenic nematodes.
Abstracts
1. Jiang-H; Yang-HW; Zhang-NX. 1995. An improvement of the centrifugal flotation method to recover entomopathogenic nematodes from soil. Chinese-Journal-of-Biological-Control. 11:1, 13-16; 3 ref.
AB: An improvement of Saunders' centrifugal flotation method to recover nematodes from soil is described. The nematodes in the supernatant liquid from the first spinning were counted. The average recovery rate of Steinernema carpocapsae increased from 32.2% (by Saunders' method) to 60.2% (by the improved method). No noticeable adverse effect on nematode survival and infectivity to Carposina nipponensis larvae was observed after centrifugal treatments, but the proportion of nematode with cuticles was slightly reduced. The same recovery rate was obtained by using a salt solution (200 g/litre) instead of sucrose solution (454 g/litre) as flotation agent. The cost of centrifugal procedure by the improved method was reduced.
ARGENTINA-TECHNIQUE
2. Doucet-MMA-de; Giayetto-AL; Bertolotti-MA; Doucet-MMA-de; Giayetto-AL; Bertolotti-MA; de-Doucet-MMA. 1998 Efficiency of the rapid technique to detect entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in soil. Nematologia-Mediterranea. 26:2, 139-143; 11 ref. Eficiencia de la tecnica rapida para deteccion de nematodos entomopatogenos (STEINERNEMAtidae y Heterorhabditidae) en suelo. Laboratorio de Nematologia, Centro de Zoologia Aplicada. Universidad Nacional de Cordoba, Casilla de Correo 122. 5000 Cordoba, Argentina.
AB: The efficiency of this rapid technique was evaluated to determine how many nematodes can be recovered when a single species is present in the soil and whether it permits the detection of more than one species. The soil was artificially infested with infective juveniles belonging to Heterorhabditis bacteriophora and/or Steinernema glaseri. The nematodes were recovered and quantified by manual dissection or enzymatic digestion. The use of the technique allows the detection of all the active infective juveniles when a single species is present, and indicates the presence of 2 species in the same sample with the results being obtained within 48 h.
3. Grenier-E; Laumond-C; Abad-P. 1995. Characterization of a species-specific satellite DNA from the entomopathogenic nematode Steinernema carpocapsae. Molecular-and-Biochemical-Parasitology, 69:1, 93-100.
AB: An HaeIII satellite DNA family was cloned from S. carpocapsae. This repeated sequence appears to be an unusually abundant satellite DNA, since it constitutes about 62% of the S. carpocapsae genome. The nucleotide sequences of 13 monomers were determined. This satellite DNA family is represented by 2 sub-families: one with monomeric units of 170bp and the other with monomeric units of 182bp. These monomers are quite homogeneous in sequence, showing an average inter monomer variability of 6% from the consensus sequence. These results suggest that some homogenizing mechanism is acting to maintain the homogeneity of this satellite DNA. After hybridization with the genomic DNA of several other Steinernema species, this DNA sequence appears to be specific to the S. carpocapsae genome. Therefore, the species specificity and the high copy number of the HaeIII satellite DNA sequence should provide a rapid and powerful tool which could contribute to the identification of Steinernema species.
4. Doucet-MMA-de; Giayetto-AL; Bertolotti-MA; Doucet-MMA-de; Giayetto-AL; Bertolotti-MA; de-Doucet-MMA. 1998. Efficiency of the rapid technique to detect entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in soil. Laboratorio de Nematologia, Centro de Zoologia Aplicada. Universidad Nacional de Cordoba, Casilla de Correo 122. 5000 Cordoba, Argentina.
AB: The efficiency of this rapid technique was evaluated to determine how many nematodes can be recovered when a single species is present in the soil and whether it permits the detection of more than one species. The soil was artificially infested with infective juveniles belonging to Heterorhabditis bacteriophora and/or Steinernema glaseri. The nematodes were recovered and quantified by manual dissection or enzymatic digestion. The use of the technique allows the detection of all the active infective juveniles when a single species is present, and indicates the presence of 2 species in the same sample with the results being obtained within 48 h.
5. Zhang-SG; Yang-HW. 1988. Improvement of the techniques for maintaining bacterial symbionts of entomopathogenic nematodes on agar slant. Chinese-Journal-Of-Biological-Control, 4:3, 111-113.
AB:Fourteen bacterial symbionts, whose nematode hosts were Steinernema glaseri [Neoaplectana glaseri], S. feltiae [N. feltiae], S. bibionis [N. bibionis], S. affinis [N. affinis], and Heterorhabditis heliothidis, were tested for the duration of maintenance on nutrient agar slant at 10°C. The results demonstrated that the symbionts kept their primary form and antibiotic activities for at least 6 months, enabling subculture of the bacteria every 6 months, instead of monthly as when using the conventional subculture method on YS agar at 12°C.
CHINA- STAINING
6. Yang-HW; Jian-H. 1988 Labelling living entomopathogenic nematodes with stains. Chinese-Journal-of-Biological-Control. 4:2, 59-61; 3 ref. Biol. Control Lab., Chinese Acad. Agric. Sci., Beijing, China.
AB: Different stages of Steinernema feltiae [Neoaplectana carpocapsae], S. bibionis [N. bibionis] and S. glaseri [N. glaseri] were stained with one of 7 biological stains added to the media at 0.5%. Nematodes stained with Sudan II and Sudan III showed red colour in their intestinal contents and fat bodies, and were easily distinguishable. The colour of the stained nematodes lasted until they penetrated insect hosts. The stains had no adverse effect on their fecundity or infectivity. It is concluded that this method is effective for identifying and tracing the activities of nematodes used in laboratory experiments.
7. Fitters-PFL; Meijer-EMJ; Wright-DJ; Griffin-CT. 1997. Estimation of lipid reserves in unstained living and dead nematodes by image analysis. Journal-of-Nematology. 29:2, 160-167; 22 ref.
AB: Optical density per unit area (OD per area) of infective juveniles of Steinernema carpocapsae (All) and two Heterorhabditis isolates (UK211 and HF85) was measured with an image analysis system and compared with neutral lipid levels obtained by Oil Red O staining. Optical density (OD) measurements were compared with triglyceride levels of UK211 and HF85. Good correlations between OD per area and neutral lipids (0.90) and between OD and triglycerides (0.87) were found. Thus, OD reflects lipid levels and can be used as an indicator of lipid reserves in these nematodes. Heat-killing of nematodes had no significant effect on OD measurements, but length increased significantly. Storage in a triethanolamine in formaldehyde solution decreased the OD and OD/area by about 5% to 8%. An additional advantage of the image analysis method described is that repeated measurements can be performed on live nematodes.
8. Smith-BS; Hodgson-Smith-A; Popiel-I; Minter-DM; James-ER. 1990. Cryopreservation of the entomogenous nematode parasite Steinernema feltiae (= Neoaplectana carpocapsae). Cryobiology. 27:3, 319-327.
AB: Cryopreservation studies were conducted with the J1 juvenile and 3rd-stage infective juvenile (IJ) larvae of Steinernema feltiae (Neoaplectana feltiae). The main parameters evaluated were: tolerance of the organisms to the cryoprotectants methanol, ethanediol, glycerol and dimethyl sulphoxide; the incubation temperature and exposure period in cryoprotectant; and slow cooling (circa 10C/min) vs. rapid cooling (circa 5-100C/min). The J1 stage was sensitive to all cryoprotectants at >20% (v/v). This sensitivity increased at 22 and 370C. Exsheathed IJ stage organisms tolerated exposure to 50% (v/v) ethanediol or ME2SO and 60% (v/v) methanol or glycerol. A proportion (3.4%) of J1s preincubated in 20% (v/v) methanol for 10 min at 0°C survived slow cooling to -35°C followed by a plunge into liquid nitrogen. Preincubation in 60% (v/v) ME2SO for 45 sec at 0°C followed by rapid cooling yielded a higher proportion (12.3%) of surviving J1s. The infective IJ stage only survived rapid cooling. Preincubation for 20 min at 0°C in either 60% (v/v) methanol or 45% glycerol, followed by rapid cooling at 5-100C/min, yielded 30-34% viable IJs following thawing. These larvae were capable of further growth and development in vitro. The results suggest that the organisms are vitrified during the rapid cooling step. For routine maintenance of strains of N. feltiae and related general it is preferable to use the IJ stage.
9. Lee-SeungHwa; Kim-YongGyun; Han-SangChan; Lee-SH; Kim-YG; Han-SC. 2000. Cryopreservation of the entomopathogenic nematode, Steinernema carpocapsae Weiser. Korean-Journal-of-Applied-Entomology. 39:3, 149-152; 18 ref.
Cryopreservation of infective juveniles of Steinernema carpocapsae Weiser, was conducted at -190°C liquid nitrogen and its efficacy was analysed on nematode survival and pathogenicity with glycerol pretreatments and storage periods. Infective juveniles were pre-treated before being frozen by incubating the nematodes in 22% glycerol for each of 6, 12, and 24 h, followed by 70% methanol at 0°C for 10 minutes. Just after glycerol and methanol incubations, subsamples of the nematodes were resuspended in 0.85% saline and maintained during 24h for viability determination. Different glycerol incubation periods significantly affected the nematode susceptibility to methanol infiltration. Six hour incubation in glycerol resulted in much less nematode survival than did 12 h or 24 h incubation. About 70% of the infective juveniles frozen at -190°C for 5 months, preincubat-ed in glycerol at least for 12h, were able to survive after being resuspended in 30°C saline. They did not show any change in their pathogenicity during cryopreservation. These results suggest an improved technique for long-term storage of the entomopathogenic nematodes.