Nematode Information » entomopathogenic nematodes

Mode of action of entomopathogenic nematodes

Ganpati Jagdale — Sun, 01 Aug 2010 21:52:54 +0000

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.

Entomopathogenic nematodes can be used for controlling pests of stored grains

Ganpati Jagdale — Fri, 18 Jun 2010 04:02:11 +0000

It has been demonstrated that the efficacy of entomopathogenic nematodes (Heterorhabditis bacteriophora, Steinernema carpocapsae, and Steinernema feltiae against various stored grain pests (Mediterranean flour moth, Ephestia kuehniella, lesser grain borer, Rhyzopertha dominica, rice weevil, Sitophilus oryzae and confused flour beetle, Tribolium confusum) of wheat (Triticum aestivum L.) varied with nematode dosages and temperature in the storage structures.

Please read following papers for detailed information on the interaction between entomopathogenic nematodes and stored grain pests.

Athanassiou, C.G., Kavallieratos, N.C., Menti, H. and Karanastasi, E. 2010. Mortality of four stored product pests in stored wheat when exposed to doses of three entomopathogenic nematodes. Journal of Economic Entomology. 103: 977-984.

Athanassiou, C.G., Palyvos, N.E. and Kakoull-Duarte, T. 2008. Insecticidal effect of Steinernema feltiae (Filipjev) (Nematoda : Steinernematidae) against Tribolium confusum du Val (Coleoptera : Tenebrionidae) and Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) in stored wheat Journal of Stored Products Research. 44: 52-57.

Mbata, G.N., and Shapiro-Ilan, D.I. 2005. Laboratory evaluation of virulence of heterorhabditid nematodes to Plodia interpunctella Hübner (Lepidoptera: Pyralidae). Environmental Entomology. 34: 676 – 682.

Ramos-Rodríguez, O., Campbell, J. F. and Ramaswamy, S. 2006. Pathogenicity of three species of entomopathogenic nematodes to some major stored- product insect pest. Journal of Stored Product Research 42: 241 – 252.

Ramos-Rodríguez,O., Campbell, J. F. and Ramaswamy, S. 2007. Efficacy of the entomopathogenic nematodes Steinernema riborave against the stored-product pests Tribolium castaneum and Plodia interpunctella. Biological Control 40:15 -21.

Tradan, S., Vidric, M. and Valic, N. 2006. Activity of four entomopathogenic nematodes against young adult of Sitophilus granarious (Coleptera: Curculionidae ) and Oryzophilus surinamensis ( Coleoptera: Silvanidae ) under laboratory condition. Plant Disease and Protection. 113: 168 – 173.

Do you know that the queens of red imported fire ants can be susceptible to entomopathogenic nematodes?

Ganpati Jagdale — Sun, 06 Jun 2010 02:47:04 +0000

As we know that the red imported fire ants (Solenopsis invicta Buren) are most notorious and difficult to control. These ants are considered as a major agricultural and urban pest and they can be medically and environmentally harmful. Red imported fire ants generally invade home lawns, school yards, athletic fields, golf courses and parks. Natural enemies including microsporidian protozoan (Thelohania solenopsae) the fungus (Beauveria bassiana), South African parasitoid flies (Pseudacteon tricuspis and Pseudacteon curvatus) and entomopathogenic nematodes have a potential to use as a biological control agents to kill red imported fire ants.

Recently, it has been reported that the infective juveniles of two entomopathogenic nematode species including Steinernema carpocapsae All and S. scapterisci can infect the queens of the red imported fire ant, Solenopsis invicta under laboratory conditions. Both nematodes can cause up to 100% mortality of fire ant queens 9 days after their exposure. For correct dosages of nematodes and their efficacy, please read the paper listed below.

Zhang, L.K., Zhang, P.B., Cao, L. and Han, R.C. 2010. Susceptibility of red imported fire ant queens to the entomopathogenic nematodes Steinernema carpocapsae All and S. scapterisci. Sociobiology. 55: 519-526.

Kill cereal leaf beetles, Oulema melanopus with entomopathogenic nematodes

Ganpati Jagdale — Fri, 02 Apr 2010 14:14:17 +0000

Recently, it has been demonstrated that the entomopathogenic nematodes including Steinernema feltiae strain B30, S. carpocapsae strain C101, and Heterorhabditis bacteriophora strain D54 have a potential to use as biological control agents against cereal leaf beetles (Oulema melanopus), which is a most common pest of many cereal crops including barley, corn, oats, wheat, rye, millet and rice.

For more information on interaction between entomopathogenic nematodes and cereal leaf beetles read following research paper.

Laznik, Z., Toth, I., Lakatos, T., Vidrih, M. and Trdan, S. 2010. Oulema melanopus (L.) (Coleoptera: Chrysomelidae) adults are susceptible to entomopathogenic nematodes (Rhabditida) attack: results from a laboratory study. Journal of Plant Diseases and Protection. 117: 30-32.

Can you kill small hive beetles (Aethina tumida) with entomopathogenic nematodes?

Ganpati Jagdale — Thu, 25 Feb 2010 04:37:51 +0000

Entomopathogenic nematodes including Steinernema riobrave and Heterorhabditis indica were evalusted against a small hive beetle Aethina tumida Murray (Coleoptera: Nitidulidae) in the field. According to Ellis et al. (2010) both nematode species caused over 76% mortality of hive beetles. Shapiro-Ilan et al. (2010) tested efficacy of H. indica and Steinernema carpocapsae against hive beetles and demonstrated that both nematode species when applied through infected host cadavers can cause up to 78% control in hive beetles. This suggests that entomopathogenic nematodes have a potential to use as biological control agents against hive beetles.

Read following papers for detail information on effect of entomopathogenic nematodes on the small hive beetles.

Ellis, J.D., Spiewok, S., Delaplane, K.S., Buchholz, S., Neumann, P. and Tedders, W.L. 2010. Susceptibility of Aethina tumida (Coleoptera: Nitidulidae) larvae and pupae to entomopathogenic nematodes. Journal of Economic Entomology. 103: 1-9.

Shapiro-Ilan, D.I., Morales-Ramos, J.A., Rojas, M.G. and Tedders, W.L. 2010. Effects of a novel entomopathogenic nematode-infected host formulation on cadaver integrity, nematode yield, and suppression of Diaprepes abbreviatus and Aethina tumida. Journal of Invertebrate Pathology. 103: 103-108.

Can you control stored grain insect pests with entomopathogenic nematodes?

Ganpati Jagdale — Sat, 06 Feb 2010 19:19:28 +0000

Pulse (legume) grains are considered as the important sources of protein, fats, carbohydrates, sugar and vitamin. B. In developing countries pulses are a cheaper protein source than meat. Many insect pests including red flour beetle Tribolium castaneum (Herbst), India meal moth Plodia interpunctella, Mediterranean flour moth Ephestia kuehniella (Zeller), saw thoothed grain beetle Oryzaephilus surinomensis (L.), yellow mealworm Tenebrio molitor (L.) and the ware house beetle Trogoderma variable (Ballion) cause a serious damage to these crops in the field and grains in the storage. The efficacy of entomopathogenic nematodes against many stored grain/product pests have been studied by many researchers (Athanassiou et al., 2008; Moris, 1985; Romos-Rodriguez et al., 2006). In the laboratory, an entomopathogenic nematode, Steinernema feltiae when applied at the rate 900 infective juveniles per insect caused over 66% mortality of both adults and larvae of T. confusum. This nematode when applied at the same rate also caused over 52% mortality of E. kuehniella. (Athanassiou et al., 2008) Under laboratory conditions, another species of nematode, S. riobrave can cause about 70% mortality of T. castaneum (Ramos-Rodríguez et al., 2007). It has also been demonstrated that nematodes including S. carpocapsae, Heterorhabditis bacteriophora and H. megidis have a potential to control the adults of two stored grain pests including, Sitophilus granarius and O. surinamensis (Tradan, 2006). Mbata and Shapiro-IIan (2005) also showed that various heterorhabditis nematodes including H. bacteriophora (HP88, Lewiston, and Oswego strains); H. indica (Homl strain); H. marelatus (Point Reyes strain); H. megidis (UK211 strain); and H. zealandica (NZH3 strain) have potential to kill larvae and adults of P. interpunctella.

For more information on biological control of stored grain pets with entomopathogenice nematodes; please read following research papers:

Athanassiou CG, Palyvos NE, Kakoull-Duarte T. 2008. Insecticidal effect of Steinernema feltiae (Filipjev) (Nematoda : Steinernematidae) against Tribolium confusum du Val (Coleoptera : Tenebrionidae) and Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) in stored wheat Journal of Stored Products Research. 44: 52-57.

Ramos-Rodríguez, O., Campbell, J. F., and Ramaswamy, S. 2006. Pathogenicity of three species of entomopathogenic nematodes to some major stored- product insect pest. Journal of Stored Product Research 42: 241 – 252.

Ramos-Rodríguez,O.,Campbell, J. F.,and Ramaswamy, S. 2007. Efficacy of the entomopathogenic nematodes Steinernema riborave against the stored-product pests Tribolium castaneum and Plodia interpunctella. Biological Control 40:15 -21.

Tradan, S., Vidric, M., and Valic, N. 2006. Activity of four entomopathogenic nematodes against young adult of Sitophilus granarious (Coleptera: Curculionidae ) and Oryzophilus surinamensis ( Coleoptera: Silvanidae ) under laboratory condition. Plant Disease and Protection. 113: 168 – 173.

Entomopathogenic Nematodes and fungus gnats

Ganpati Jagdale — Fri, 29 Jan 2010 04:14:18 +0000

Several fungus gnat species including Bradysia coprophila, B. impatiens and B. difformis are considered economically important indoor and greenhouse pests in Europe and the US. Fungus gnat flies are black or gray in color with clear wings, relatively small (3-4 mm) in size and commonly associated with compost and natural soils with high organic contents. You can see these hopping flies when you water your plants. Fungus gnat maggots (larvae) are white-bodied with black heads and can be found just under the surface of the potting medium/soil. These maggots primarily feed on fungi and organic matter but they can also cause a serious damage to many ornamental plants. Maggots often chew or strip plant roots and tunnel stems affecting water and nutrient absorption in severely injured plants resulting in lost vigor, turn off-color and eventually death. Maggots are also capable of transmitting fungal pathogens (Fusarium, Phoma, Pythium and Verticillium) during feeding. Adult flies are nuisance to people and disseminate fungal spores from plant to plant as they disperse through the greenhouse. Females often laying over 1000 eggs in a lifetime on the media surface and completing egg-to-egg life cycle within 20-25 days at 20-25oC. Continuous and overlapping generations of fungus gnats in the greenhouse have made most control strategies difficult.
Currently, most growers rely on insecticides to manage fungus gnats in floriculture. However, use of these insecticides is restricted due to their environmental pollution and human health concerns, development of resistance to pesticides and removal of some of the most effective products from the market. Biological control agents including Bacillus thuringiensis (Bt), the predatory mite, Hypoaspis miles and entomopathogenic nematodes have been used as alternatives to chemical pesticides.
The entomopathogenic nematodes species including Heterorhabditis bacteriophora GPS11 strain, H. indica LN2 strain and Steinernema feltiae UK strain have a potential to use as biocontrol agents against fungus gnats. These nematodes kill both maggots (larvae) and pupae, but the second and fourth stages are most susceptible than pupae. Nematodes are generally applied in water suspension as spray applications to the surface of plant growing medium to target larval and pupal stages. The potting medium (Ball-mix, Nursery-mix or Pro-mix) can influence the survival, persistence and efficacy of entomopathogenic nematodes in greenhouse production. In the Nursery-mix, H. bacteriophora can survive longer and perform better than H. indica, H. marelatus Oregon, H. zealandica X1 and Steinernema feltiae against fungus gnats. In the Pro-mix, only H. indica have performed better than all other nematode species that tested against fungus gnats. Application of S. feltiae can cause 40% reduction in fungus gnat population in Ball-mix, 50% in Metro-mix and 56% in Pro-mix, but only 27% in the Nursery-mix. In the greenhouse, temperature can influence efficacy of nematodes. For example, H. bacteriophora and H. indica can survive and cause very high mortality of fungus gnats at warmer (above 25oC) temperatures whereas S. feltiae is generally effective against fungus gnats at cooler (below 25oC) temperatures. Application of an appropriate concentration of nematodes is a crucial step in the cost effective control of fungus gnats in greenhouse production. Generally, application of one billion infective juveniles of H. bacteriophora, H. indica or S. feltiae per acre can kill over 50% fungus gnats in greenhouse productions.

How entomopathogenic nematodes kill fungus gnats

When the infective juveniles are applied to the surface of plant growing medium, they start searching for hosts, in this case fungus gnat maggots (larvae) and pupae.
Once a maggot/pupa has been located, the nematode infective juveniles penetrate into the maggot body cavity via natural openings such as mouth, anus and breathing pores called spiracles.
Infective juveniles of Heterorhabditis spp also enter through the intersegmental members of the maggot/pupal cuticle.
Once in the body cavity, infective juveniles release symbiotic bacteria (Xenorhabdus spp. for Steinernematidae and Photorhabdus spp. for Heterorhabditidae) from their gut in the fungus gnat blood.
Multiplying nematode-bacterium complex causes septicemia and kills the host usually within 48 h after infection.
Nematodes feed on multiplying bacteria, mature into adults, reproduce and then emerge as infective juveniles from the cadaver to seek new maggots in the potting medium/soil.

Nematodes are now commercially available from many suppliers distributed throughout in the USA.

For more information on biological control of fungus gnats, please read following research papers/book chapters:

Binns, E.S., 1973. Fungus gnats (Diptera: Mycetophilidae, Sciaridae) and the role of mycophagy in soil: a review. Rev. Ecol. Biol. Sol. 18, 77-90.
Chambers, R.J., Wright, E.M., Lind, R.J., 1993. Biological control of glasshouse sciarid larvae (Bradysia spp.) with the predatory mite, Hypoaspis miles on Cyclamen and Poinsettia. Biocontrol Sci. Technol. 3, 285-293.
Ecke, P.Jr., Faust, J.E., Williams, J., Higgins, A., 2004. The Poinsettia Manual. Ball Publishing, The Paul Ecke Ranch, Encinitas, California, USA.
Freeman, P., 1983. Sciarid flies, Diptera; Sciaridae. Handbooks for the identification of British insects 9, Part 6. London, Royal Entomol. Soc. pp 68.
Gillespie, D.R., Menzies, J.G., 1993. Fungus gnat vector Fusarium oxysporum f. sp. radicislycopersici. Ann. Appl. Biol. 123, 539-544.
Gouge, D.H., Hague, N.G.M., 1994. Control of sciarids in glass and propagation houses with Steinernema feltiae. Brighton Crop Protection Conference: Pest Dis. 3, 1073-1078.
Gouge, D.H., Hague, N.G.M., 1995. Glasshouse control of fungus gnats, Bradysia paupera, on fuchsias by Steinernema feltiae. Fundam. Appl. Nematol. 18, 77-80.
Grewal, P.S., Richardson, P.N., 1993. Effects of application rates of Steinernema feltiae (Nematoda: Steinernematidae) on control of the mushroom sciarid fly, Lycoriella auripila (Diptera: Sciaridae). Biocontrol Sci. Technol. 3, 29-40.
Grewal, P.S., Tomalak, M., Keil, C.B.O., Gaugler, R., 1993. Evaluation of a genetically selected strain of Steinernema feltiae against the mushroom sciarid fly, Lycoriella mali. Ann. Appl. Biol. 123, 695-702.
Harris, M.A., Oetting, R.D., Gardner, W.A., 1995. Use of entomopathogenic nematodes and new monitoring technique for control of fungus gnats, Bradysia coprophila (Diptera: Sciaridae), in floriculture. Biol. Control 5, 412-418.
Jagdale, G. B., Casey, M. L., Grewal, P. S. and Lindquist, R. K. 2004. Application rate and timing, potting medium and host plant on the efficacy of Steinernema feltiae against the fungus gnat, Bradysia coprophila, in floriculture. Biol. Contrl. 29: 296-305.
Jagdale, G. B., Casey, M. L., Grewal, P. S. and Luis Cañas. 2007. Effect of entomopathogenic nematode species, split application and potting medium on the control of the fungus gnat, Bradysia difformis (Diptera: Sciaridae), in the greenhouse at alternating cold and warm temperatures. Biol. Control. 43: 23-30.
Kim, H.H., Choo, H.Y., Kaya, H.K., Lee, D.W., Lee, S.M., Jeon, H.Y., 2004. Steinernema carpocapsae (Rhabditida: Steinernematidae) as a biological control agent against the fungus gnat Bradysia agrestis (Diptera: Sciaridae) in propogation houses. Biocontrol Sci. Technol. 14, 171-183.
Lindquist R., Piatkowski J. 1993. Evaluation of entomopathogenic nematodes for control of fungus gnat larvae. Bull. Int. Organiz. Biol. Integr. Control Noxious Animals and Plants. 16, 97-100.
Lindquist, R.K., Faber, W.R., Casey, M.L., 1985. Effect of various soilless root media and insecticides on fungus gnats. HortScience. 20, 358-360.
Menzel, F., Smith, J.E., Colauto, N.B., 2003. Bradysia difformis Frey and Bradysia ocellaris (Comstock): two additional neotropical species of black fungus gnats (Diptera : Sciaridae) of economic importance: a redescription and review. Ann. Entomol. Soc. Am. 96, 448-457.
Nielsen, G. R., 2003. Fungus gnats. http://www.uvm.edu/extension/publications/el/el50.htm
Oetting, R.D., Latimer, J.G., 1991. An entomogenous nematode Steinernema carpocapsae is compatible with potting media environments created by horticultural practices. J. Entomol. Sci. 26, 390-394.
Olson, D.L., Oetting, R.D., van Iersel, M.W., 2002. Effect of soilless media and water management on development of fungus gnats (Diptera: Sciaridae) and plant growth. HortScience. 37: 919-923.
Richardson, P.N., Grewal, P.S., 1991. Comparative assessment of biological (Nematoda: Steinernema feltiae) and chemical methods of control of mushroom fly, Lycoriella auripila (Diptera: Sciaridae). Biocontrol Sci. Technol. 1, 217-228.
Tomalak, M., Piggott, S. and Jagdale, G. B. 2005. Glasshouse applications. In: Nematodes As Biocontrol Agents. Grewal, P.S. Ehlers, R.-U., Shapiro-Ilan, D. (eds.). CAB publishing, CAB International, Oxon. Pp 147-166.
Wilkinson, J.D., Daugherty, D.M., 1970. Comparative development of Bradysia impatiens (Diptera: Sciaridae) under constant and variable temperatures. Ann. Entomol. Soc. Am. 63, 1079-1083.

Plants can call for help for their protection against insect pests

Ganpati Jagdale — Sun, 27 Dec 2009 14:58:54 +0000

It has been demonstrated that the plants when attacked by herbivorous insects can emit volatile compounds that can attract natural enemies of the insects. For example, the roots of maize plants when attacked by western corn root-worms (a noxiuos insect pest of corn) can synthesize and emit a volatile compound called (E)-beta-caryophyllene that attracts insect-parasitic nematodes that infect and kill many soil dwelling insect pests (Rasmann et al., 2005; Degenhardt et al., 2009).

Read following scientific papers for more information on insect induced plant volatiles that attract natural enemies of insect pests.

Degenhardt, J., Hiltpold, I., Kollner, T.G., Frey, M., Gierl, A., Gershenzon, J., Hibbard, B.E., Ellersieck, M.R. and Turlings, T.C.J. 2009. Restoring a maize root signal that attracts insect-killing nematodes to control a major pest. Proceedings of the National Academy of Sciences of the United States of America. 106: 13213-13218.

Rasmann, S., Kollner, T.G., Degenhardt, J., Hiltpold, I., Toepfer, S., Kuhlmann, U., Gershenzon, J., Turlings T.C.J. 2005. Recruitment of entomopathogenic nematodes by insect-damaged maize roots. Nature 434: 732–737.

Use insect-parasitic nematodes to control citrus root weevils

Ganpati Jagdale — Sun, 27 Dec 2009 00:12:40 +0000

The citrus root weevil also called as Diaprepes root weevil (Diaprepes abbreviatus) is one of the major insect pests of citrus and many ornamental plants in Florida and California. Several researchers have demonstrated that the application of an insect-parasitic nematode can supress the populations of root weevils in citrus orchards. For example, Steinernema riobrave infective juveniles when applied in citrus orchards or greenhouses can provide 50 to 90% reduction in populations of D. abbreviatus (Bullock et al., 1999; Duncan and McCoy, 1996; Duncan et al., 1996; Shapiro and McCoy, 2000ab). Applications of S. carpocapsae (All strain), Heterorhabditis bacteriophora (HP-88 strain) or H. bacteriophora (Florida strain) in the citrus grove can also reduce 50-70% adult emergence of D. abbreviatus (Duncan et al., 1996; Schroeder, 1992). According to Shapiro et al. (1999), S. riobrave, H. bacteriophora and H. indica were highly virulent against younger (50-day-old) than older (100-day-old) D. abbreviatus larvae at 24 or 27 degrees C temperature. Heterorhabditis indica was more virulent than H. bacteriophora in 50-day-old D. abbreviatus larvae at all temperatures. However, H. bacteriophora was more virulent than S. riobrave in 20-day-old larvae at 24 degrees C but it was less virulent than S. riobrave in 50-day-old larvae at 21 degrees C.

Please Read following literature for detailed information on interaction between insect-parasitic nematodes and citrus root weevil.

Bullock, R.C., Pelosi, R.R. and Killer, E.E. 1999. Management of citrus root weevils (Coleoptera : Curculionidae) on Florida citrus with soil-applied entomopathogenic nematodes (Nematoda : Rhabditida). Florida Entomologist. 82: 1-7.

Duncan, L.W and McCoy, C.W. 1996 Vertical distribution in soil, persistence, and efficacy against citrus root weevil (Coleoptera: Curculionidae) of two species of entomogenous nematodes (Rhabditida: Steinernematidae; Heterorhabditidae). Environmental Entomology. 25: 174-178.

Duncan, L.W. McCoy, C.W. and Terranova, A.C. 1996. Estimating sample size and persistence of entomogenous nematodes in sandy soils and their efficacy against the larvae of Diaprepes abbreviatus in Florida. Journal of Nematology. 28: 56-67.

Schroeder, W.J. 1992. Entomopathogenic nematodes for control of root weevils of citrus. Florida Entomologist 75: 563-567.

Shapiro, D.I. and McCoy, C.W. 2000a. Susceptibility of Diaprepes abbreviatus (Coleoptera : Curculionidae) larvae to different rates of entomopathogenic nematodes in the greenhouse. Florida Entomologist. 83: 1-9.

Shapiro, D.I. and McCoy, C.W. 2000b. Effects of culture method and formulation on the virulence of Steinernema riobrave (Rhabditida: Steinernematidae) to Diaprepes abbreviatus (Coleoptera: Curculionidae). Journal of Nematology 32: 281-288.

Shapiro, D.I., Cate, J. R., Pena, J., Hunsberger, A. and McCoy, C.W. 1999. Effects of temperature and host age on suppression of Diaprepes abbreviatus (Coleoptera : Curculionidae) by entomopathogenic nematodes. Journal of Economic Entomology. 92: 1086-1092.

Biological control of Colorado potato beetle, Leptinotarsa decemlineata with entomopathogenic nematodes

Ganpati Jagdale — Wed, 16 Dec 2009 19:46:16 +0000

Colorado potato beetle, Leptinotarsa decemlineata: This is an economically important pest of potatoes with more than 40 species have been reported from North America. The larvae of this beetle are voracious feeder of potato leaves costing hundreds of millions of dollars for pesticide control and yield loss each year in the United States. Entomopathogenic nematodes as biological control agents could provide an alternative to chemical pesticides in management of this noxious pest.

In a laboratory bioassay, four species of entomopathogenic nematodes including Steinernema carpocapsae, S. feltiae, Heterorhabditis bacteriophora, and H. megidis showed highest virulence against both larval and adult stages of the Colorado potato beetle, Leptinotarsa decemlineata at temperatures higher than 15oC when tested at the rate of 200 -2000 infective juveniles per individual of Colorado potato beetle (Trdan et al., 2009).

In another laboratory study, entomopathogenic nematode, H. marelata can cause 100% mortality of Colorado potato beetle larvae (Berry et al., 1997) but in the field, this nematode when applied twice in potato growing season can reduce only 50% population of adult Colorado potato beetles (Armer et al., 2004).

The efficacy of pesta-pelletized Steinernema carpocapsae All strain was tested against prepupal stages of Colorado potato beetle in a greenhouse (Nickle et al., 1994). Infective juveniles of S. carpocapsae were able to survive the pesta-pellet process and able to reduce over 90% emergence of adults of Colorado potato beetle.

It has been also reported that prepupal stages of Colorado potato beetle were very susceptible to different species/strains of entomopathogenic nematodes including S. carpocapsae All strain; S. carpocapsae Mexican strain; S. feltiae strain #27; S. feltiae strain #980 and Heterorhabditis bacteriophora. All these nematode species caused 100% mortality of beetle prepupae when applied in the soil at the concentration of 165 infective juveniles/cm2 (Cantelo and Nickle, 1992).

For more information, read following literature on interaction between entomopathogenic nematodes and Colorado potato beetle.

Armer, C.A., Berry, R.E., Reed, G.L. and Jepsen, S.J. 2004. Colorado potato beetle control by application of the entomopathogenic nematode Heterorhabditis marelata and potato plant alkaloid manipulation. Entomologia Experimentalis et Applicata. 111: 47-58.

Berry, R.E., Liu, J. and Reed, G. 1997. Comparison of endemic and exotic entomopathogenic nematode species for control of Colorado potato beetle (Coleoptera : Chrysomelidae). Journal of Economic Entomology. 90: 1528-1533.

Cantelo, W.W. and Nickle, W.R. 1992. Susceptibility of prepupae of the Colorado potato beetle (coleoptera, chrysomelidae) to entomopathogenic nematodes (Rhabditida, Steinernematidae, Heterorhabditidae). Journal of Entomological Science. 27: 37-43.

Nickle, W.R., Connick, W.J. and Cantelo, W.W. 1994. Effects of pesta-pelletized steinernema-carpocapsae (all) on western corn rootworms and colorado potato beetles. Journal of Nematology. 26: 249-250.

Trdan, S., Vidrih, M., Andjus, L. and Laznik, Z. 2009. Activity of four entomopathogenic nematode species against different developmental stages of Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera, Chrysomelidae. Helminthologia. 46: 14-20.