Efficacy of carboxymethyl cellulose as an inert water-soluble carrier for formulation of entomopathogenic nematodes, heterorhabditis bacteriophora and steinernema carpocapsae

AbstractCentrifugation, desiccation, agitation, and handling of entomopathogenic nematodes in the laboratory during isolation, culture, storage, formulation and experimentation, influences nematode ability to tolerate adverse environmental conditions. Stress imposed by centrifugation (5-60 min), desiccation (3-9 days), agitation (3-24 h), and handling (2-10 times) reduced stress and heat tolerance in Heterorhabditis bacteriophora and Steinernema carpocapsae. Short durations of stresses (e.g., 5 min of centrifugation, 3-5 days of desiccation, 3 h of agitation and 2-4 times of handling) did not affect nematodes, whereas prolonged durations (e. g., 10-60 min of centrifugation, 7-9 days of desiccation, 6-24 h of agitation and 6-10 times of handling) significantly decreased heat tolerance. Steinernema carpocapsae tolerated stress comparatively better than H. bacteriophora by showing a significantly greater degree of heat tolerance. This study provides a basis to investigate further the effects of physical and chemical stresses in order to minimise handling of laboratory nematodes and reduce disruptions of their normal function and behaviour.

Download Full-text

Use of species-specific satellite DNAs as diagnostic probes in the identification of Steinernematidae and Heterorhabditidae entomopathogenic nematodes

Parasitology ◽

10.1017/s0031182000081555 ◽

1996 ◽

Vol 113 (5) ◽

pp. 483-489 ◽

Cited By ~ 20

Author(s):

E. Grenier ◽

E. Bonifassi ◽

P. Abad ◽

C. Laumond

Keyword(s):

Entomopathogenic Nematodes ◽

Heterorhabditis Bacteriophora ◽

Steinernema Carpocapsae ◽

Infective Juvenile ◽

Satellite Dnas ◽

Satellite Sequences ◽

Species Specific

SUMMARYThree satellite DNAs previously isolated from the entomopathogenic nematodes Steinernema carpocapsae, Heterorhabditis bacteriophora and Heterorhabditis indicus give hybridization signals only with the S. carpocapsae, H. bacteriophora and H. indicus populations tested, indicating that these satellite sequences are species-specific. Because of their reiteration and their variabilities, we have shown that these sequences are able to discriminate at the interspecific level between the Steinernema and Heterorhabditis species, but also at the intraspecific level between S. carpocapsae strains. Furthermore, in simple squashed nematode experiments, we are able to unambiguously identify S. carpocapsae, H. bacteriophora and H. indicus populations. This last procedure is effective even on a single infective juvenile, with the main advantage that it avoids time-consuming DNA extractions.

Download Full-text

Changes in foraging behaviour during the infective stage of entomopathogenic nematodes

Parasitology ◽

10.1017/s0031182000065306 ◽

1995 ◽

Vol 110 (5) ◽

pp. 583-590 ◽

Cited By ~ 25

Author(s):

E. E. Lewis ◽

S. Selvan ◽

J. F. Campbell ◽

R. Gaugler

Keyword(s):

Metabolic Rate ◽

Entomopathogenic Nematodes ◽

Storage Period ◽

Foraging Strategy ◽

Heterorhabditis Bacteriophora ◽

Steinernema Carpocapsae ◽

Foraging Strategies ◽

Infective Juvenile ◽

Infective Stage ◽

Energy Reserves

SUMMARYStudies of foraging strategies are often complicated by competing goals of the forager. In contrast, non-feeding infective juvenile entomopathogenic nematodes forage exclusively for a single host. Two questions were posed: (1) what is the relationship between metabolic rate, energy reserves and foraging strategy and (2) when a foraging strategy fails, will an infective-stage parasite switch strategies? Three species of entomopathogenic nematodes were stored in water and changes in their behaviour, metabolic rate, energy reserves, and infectivity were measured throughout the storage period. Steinernema carpocapsae ambushes insect hosts, whereas S. glaseri and Heterorhabditis bacteriophora cruise forage. Steinernema carpocapsae was least active and had the lowest metabolic rate. Heterorhabditis bacteriophora was more active and had the highest metabolic rate. Steinernema glaseri was most active and had an intermediate metabolic rate. Neither cruising species changed foraging strategy. Steinernema carpocapsae decreased nictation (a behaviour associated with ambushing only) and increased their locomotory rate. Any change in searching strategy occurred without assessment of the profitability or distribution of potential hosts, but the advantage this confers is unknown.

Download Full-text

Mortality Response of Green June Beetle (Coleoptera: Scarabaeidae) to Four Species of Entomopathogenic Nematodes

Journal of Entomological Science ◽

10.18474/0749-8004-29.2.268 ◽

1994 ◽

Vol 29 (2) ◽

pp. 268-275 ◽

Cited By ~ 2

Author(s):

Monica L. Townsend ◽

Don C. Steinkraus ◽

Donn T. Johnson

Keyword(s):

Entomopathogenic Nematodes ◽

Alimentary Tract ◽

Nematode Species ◽

Heterorhabditis Bacteriophora ◽

Steinernema Carpocapsae ◽

The Other ◽

Mortality Response ◽

Green June Beetle

Four species of entomopathogenic nematodes, Steinernema carpocapsae (Weiser) (All strain), S. feltiae (Filipjev) (NC strain), S. glaseri (Steiner), and Heterorhabditis bacteriophora Poinar, were tested in the laboratory for their effect on larvae of the green June beetle, Cotinus nitida L. When nematodes were injected into the foregut of larvae (ca. 1,000 nematodes per larva), S. carpocapsae, S. feltiae, S. glaseri, and H. bacteriophora caused similar mortality (65, 45, 65, and 63%, respectively). At a concentration of 10 nematodes per larva, S. carpocapsae produced significantly higher mortality (51%) than the other three nematode species. Increasing nematode concentrations resulted in only a slight increase in mortality of larvae injected perorally with any of the four nematode species. Water filtrates from whole nematodes or ground nematode tissue supernatants from S. carpocapsae and H. bacteriophora injected perorally into the alimentary tract did not kill green June beetle larvae. Thus, live nematodes appeared to be necessary to cause mortality. Subcuticular or peroral injections of S. carpocapsae or H. bacteriophora (1,000 nematodes per larva) produced similar mortality of green June beetle larvae ranging from 60 to 70%. Nematode-killed larvae were dissected (n=277) but only two cadavers contained live nematodes and nematodes did not successfully reproduce in any nematode-killed green June beetle larvae. Possible explanations for the failure of cadavers to produce nematode progeny are discussed.

Download Full-text

A survey of entomopathogenic nematodes of the families Steinernematidae and Heterorhabditidae (Nematoda: Rhabditida) in the north-west of Iran

Nematology ◽

10.1163/156854108x398453 ◽

2009 ◽

Vol 11 (1) ◽

pp. 107-116 ◽

Cited By ~ 23

Author(s):

Naser Eivazian Kary ◽

Gholamreza Niknam ◽

Seyed Abolgasem Mohammadi ◽

Christine Griffin ◽

Mohammad Moghaddam

Keyword(s):

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Heterorhabditis Bacteriophora ◽

Common Species ◽

Soil Samples ◽

Steinernema Carpocapsae ◽

Steinernema Feltiae ◽

North West ◽

The North ◽

First Time

AbstractDuring 2002-2004, a survey of entomopathogenic nematodes was conducted for the first time in Iran throughout the three provinces in the north-west of the country. Soil samples were tested for the presence of steinernematid and heterorhabditid nematodes by baiting with Galleria mellonella larvae. Of the 833 soil samples studied 27 were positive for entomopathogenic nematodes (3.2%), with 17 (2.0%) containing Heterorhabditis and ten (1.2%) Steinernema isolates. Morphological and molecular studies were carried out to characterise isolates. The Heterorhabditis isolates were identified as Heterorhabditis bacteriophora and Steinernema as Steinernema carpocapsae, S. bicornutum and S. feltiae. Heterorhabditis bacteriophora was the most common species, which was isolated from 17 sites across the three provinces. Steinernema feltiae was the most common species of Steinernema, which was isolated from eight sites but in only two provinces. Steinernema carpocapsae and S. bicornutum were each isolated from only one site. Steinernema spp. were isolated mainly from orchards and grasslands but Heterorhabditis was isolated mainly from grasslands and alfalfa fields.

Download Full-text