Archive

Recently, Negrisoli et al. (2010) demonstrated that entomopathogenic nematodes including Heterorhabditis indica, Steinernema carpocapsae and Steinernema glaseri were found to be compatible with many insecticides including chlorpyrifos, deltamethrin, lufenuron, deltramethrin + triazophos, diflubenzuron, gamacyhalothrin, lambdacyhalothrin, spinosad, cypermethrin, triflumuron, and permethrin under laboratory conditions.

Read following paper for more information compatibility of entomopathogenic nematodes with insecticides.

Negrisoli, A.S., Garcia, M.S., Negrisoli, C.R.C.B. 2010.  Compatibility of entomopathogenic nematodes (Nematoda: Rhabditida) with registered insecticides for Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) under laboratory conditions.  Crop Protection 29: 545-549.

Recently, Andalo, et al. (2010) demonstrated that the entomopathogenic nematodes Steinernema arenarium and Heterorhabditis sp. can kill over 80% larvae of fall army worm, Spodoptera frugiperda under both laboratory and greenhouse condition.

Read following paper for the information on the effect of entomopathogenic nematodes on fall army worm.

Andalo, V., Santos, V., Moreira, G.F., Moreira, C.C. and Moino, A.  2010. Evaluation of entomopathogenic nematodes under laboratory and greenhouses conditions for the control of Spodoptera frugiperda Ciencia Rural  40: 1860-1866.

Recently, Hyrsl et al. (2011) demonstrated that the common fruit fly, Drosophila melanogaster as an immune response can form the blood (hemolymph) clots and protect against infection by an entomopathogenic nematode (Heterorhabditis bacteriophora) and its symbiotic bacterium (Photorhabdus luminescens).

Read following papers for more information on the interaction between fruit fly and entomopathogenic nematodes.

Hyrsl, P., Dobes, P., Wang, Z., Hauling, T., Wilhelmsson, C. and Theopold, U. 2011. Clotting Factors and Eicosanoids Protect against Nematode Infections.  Journal of Innate Immunity 3: 65-70.

Recently, a quantitative real-time PCR (qPCR) technique has been developed by Campos-Herrera et al (2011) for detecting and quantifying entomopathogenic nematodes including Steinernema diaprepesi, Steinernema riobrave, Heterorhabditis indica, Heterorhabditis zealandica, Heterorhabditis floridensis and an undescribed species in the S. glaseri group from soil samples.

Read following paper for a detail protocol of quantitative real-time PCR (qPCR) technique

Campos-Herrera, R., Johnson, E. G, El-Borai, F. E., Stuart, R. J., Graham, J. H. and Duncan, L. W.2011. Long-term stability of entomopathogenic nematode spatial patterns in soil as measured by sentinel insects and real-time PCR. Annals of Applied Biology    158: 55-68.

A survey conducted during 2006 and 2008 showed the presence of both heterorhabditid and steinernematid nematodes in the Arasbaran forests and rangelands, Iran.  Based on both morphological and molecular characteristics, heterorhabditid isolates were identified as Heterorhabditis bacteriophora whereas the steinernematid isolates were identified as Steinerenma carpocapsae, S. bicornutum, S. feltiae, S. glaseri, S. kraussei.

For more information on the survey methodology nematode identification techniques read following paper.

Nikdel, M., Niknam, G., Griffin, C.T. and Kary, N.E. 2010. Diversity of entomopathogenic nematodes (Nematoda: Steinernematidae, Heterorhabditidae) from Arasbaran forests and rangelands in north-west Iran.  Nematology 12: 767-773.

Biological control of sheep lice, Bovicola ovis with entomopathogenic nematodes

Four entomopathogenic nematodes including Steinernema carpocapsae, Steinernema riobrave, Steinernema feltiae and Heterorhabditis bacteriophora have showed a very high efficacy against sheep lice, Bovicola ovis when tested under laboratory conditions at different incubation temperatures (James et al., 2010).  However,  the efficacy all the four species of entomopathogenic nematodes varied with the nematode species and incubation temperature.

For more information on the interaction between entomopathogenic nematodes and sheep lice read following paper.

1. James, P. J., Hook, S.E. and Pepper, P. M. 2010. In vitro infection of sheep lice (Bovicola ovis Schrank) by Steinernematid and Heterorhabditid nematodes.   Veterinary Parasitology    174: 85-91.

Efficacies of two biological control agents including entomopathogenic fungus (Metarhizium anisopliae) and insect-parasitic nematode (Heterorhabditis bacteriophora) against western corn rootworm, Diabrotica virgifera virgifera was compared with two insecticides including Tefluthrin (synthetic pyrethroid compound) and clothianidin (neonicotinoid compound).  According to Pilz et al (2009), insect-parasitic nematode,  H. bacteriophora was as effective as both insecticides in reducing population of the western corn rootworm.

Reference:

Pilz, C., Keller, S., Kuhlmann, U. and Toepfer, S. 2009.  Comparative efficacy assessment of fungi, nematodes and insecticides to control western corn rootworm larvae in maize.  Biocontrol. 54: 671-684.

When the infective juveniles of entomopathogenic nematodes are applied to the soil surface in the fields or thatch layer on golf courses, they start searching for their insect hosts. Once insect larva has been located, the nematode infective juveniles penetrate into the larval body cavity via natural openings such as mouth, anus and spiracles. Infective juveniles of Heterorhabditis nematodes can also enter through the intersegmental membranes of the grub cuticle. Once in the body cavity, infective juveniles release symbiotic bacteria (Xenorhabdus spp. for Steinernematidae and Photorhabdus spp. for Heterorhabditidae) from their gut in insect blood. In the blood, multiplying nematode-bacterium complex causes septicemia and kill their insect host usually within 48 h after infection. Nematodes feed on multiplying bacteria, mature into adults, reproduce and then emerge as infective juveniles from the host cadaver to seek new larvae in the soil.

Recently a survey was conducted to study the occurrence and distribution of entomopathogenic nematodes in Nepal.  Although a total of 276 soil samples were collected from various habitats, entomopathogenic nematode were found only in 29 samples.  Nematodes were isolates using the Galleria-baiting technique (Bedding and Akhurst,1975). Both heterorhabditid and steinernematid nematodes were identified at their species level using both molecular and morphological techniques.  In this survey, the occurrence of only one species of heterorhabditids including Heterorhabditis indica and four described species of steinernematids such as Steinernema abbasi, S. cholashanense, S. feltiae and S. siamkayai were reported for the first time in Nepal (Khatri-Chhetri et al., 2010).

Read following literature for more information

Bedding, R.A. and R.J. Akhurst. 1975. A simple technique for detection of insect parasitic rhabditid nematodes in soil. Nematologica. 21: 109-110.

Khatri-Chhetri, H.B., Waeyenberge, L., Manandhar, H.K. and Moens, M. 2010.  Natural occurrence and distribution of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in Nepal. Journal of Invertebrate Pathology. 103: 74-78.

When the infective juveniles of entomopathogenic nematodes are applied to the soil surface in the fields or thatch layer on glf courses, they start searching for their insect hosts. Once insect larva has been located, the nematode infective juveniles penetrate into the larval body cavity via natural openings such as mouth, anus and spiracles. Infective juveniles of Heterorhabditis nematodes can also enter through the intersegmental membranes of the grub cuticle. Once in the body cavity, infective juveniles release symbiotic bacteria (Xenorhabdus spp. for Steinernematidae and Photorhabdus spp. for Heterorhabditidae) from their gut in insect blood. In the blood, multiplying nematode-bacterium complex causes septicemia and kill their insect host usually within 48 h after infection. Nematodes feed on multiplying bacteria, mature into adults, reproduce and then emerge as infective juveniles from the host cadaver to seek new larvae in the soil.