Beneficial entomopathogenic nematode, Heterorhabditis indica– Bugsforgrowers.com
1. Introduction
Heterorhabditis indica is a heat tolerant beneficial entomopathogenic nematodes nematode that works better against many insect pests when the temperature is between 25°C and 29°C. This nematode generally search for their hosts by moving through the soil matrix, the behavior is referred to as a “cruiser” foraging strategy. This nematode has been successfully used as a biological control agent to manage small hive beetles, fungus gnats and other greenhouse pests in the US greenhouse industry.
2. Beneficial entomopathogenic nematode, Heterorhabditis indica is effective against the following pests
- Fall armyworm, Spodoptera frugiperda
- Fungus gnat, Bradysia difformis
- Indian meal moth, Plodia interpunctella
- Root weevil, Diaprepes abbreviatus
- Small hive beetle, Aethina tumida
- Western flower thrips, Frankliniella occidentalis
- White grubs, Holotrichia serrata, Leucopholis lepidophora, Hoplia philanthus, Popillia japonica
3. Key factors for Heterorhabditis indica nematode effectiveness
- Heterorhabditis indica is heat tolerant nematode and it works better against many insect pests when temperature is between 25°C and 29°C.
- This warm adapted nematode performed much better than the cold adapted entomopathogenic nematode Steinernema feltiae against fungus gnats in the greenhouse.
- H. indica has great potential to manage fungus gnats and other greenhouse pests in the US greenhouse industry because warm temperature is one of the key factors restricting use of other cold adapted species of entomopathogenic nematodes that proved to be effective against fungus gnats.
- Nematode infective juveniles always carry symbiotic bacteria, Photorhabdus luminescens in their gut and use as a weapon to kill their insect host.
- In the body cavity, infective juveniles release symbiotic bacteria, P. luminescens from their gut in insect blood where multiplying nematode-bacterium complex causes septicemia and kill their insect host usually within 24-48 hours after infection.
4. How Heterorhabditis indica nematodes work in the field
- When the infective juveniles of Heterorhabditis indica are applied to the soil surface in the fields, thatch layer on golf courses, or any potting media, 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 and in some instances they can also enter through the host cuticle.
- Once in the body cavity, infective juveniles release symbiotic bacteria, Photorhabdus luminescens in insect blood.
- In the blood, multiplying nematode-bacterium complex causes septicemia and kill their insect host usually within 24-48 hours 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 and life cycle continues.
5. Why you need beneficial Heterorhabditis indica nematodes
- they are natural parasites of insect pests so they do not pollute or harm the environment
- they can kill their hosts rapidly within 24-28 hours after infection
- they have a broad range of insect hosts
- able to search for insect hosts actively, infect and kill them
- nematodes can easily reproduce inside the dead insect body and emerge as infective juvenile that start looking for new hosts to continue the life cycle in the soil after first application
- they can be easily applied using traditional insecticide spraying equipment
6. Why Heterorhabditis indica is safer than traditional pesticides
- they do not damage plants
- can be used and applied around children and pets
- do not cause any harm to the personnel involved in their production and application
- food products are safe to handle and eat when they are treated with nematodes
- they do not harm humans, animals, beneficial insects (i.e. honey bees), microbial communities and other beneficial nematodes
Research papers
- Ansari, M.A., Adhikari, B.N., Ali, F. and Moens, M. 2008. Susceptibility of Hoplia philanthus (Coleoptera: Scarabaeidae) larvae and pupae to entomopathogenic nematodes (Rhabditida: Steinernematidae, Heterorhabditidae). Biological Control. 47: 315-321.
- Ebssa, L., Borgemeister, C. and Poehling, H.M. 2006. Simultaneous application of entomopatho genic nematodes and predatory mites to control western flower thrips Frankliniella occidentalis. Biological Control. 39: 66-74
- Jagdale, G.B., Casey, M.L., Canas, L. and Grewal, P.S. 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.
- Mbata, G.N. and Shapiro-Ilan, D.I. 2010. Compatibility of Heterorhabditis indica (Rhabditida: Heterorhabditidae) and Habrobracon hebetor (Hymenoptera: Braconidae) for biological control of Plodia interpunctella (Lepidoptera: Pyralidae). Biological Control. 54: 75-82.
- Negrisoli, A.S., Garcia, M.S. and Negrisoli, C.R.C.B. 2010a. Compatibility of entomopathogenic nematodes (Nematoda: Rhabditida) with registered insecticides for Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) under laboratory conditions. Crop Protection. 29: 545-549.
- Negrisoli, A.S., Garcia, M.S., Negrisoli, C.R.C.B., Bernardi, D. and da Silva, A. 2010b. Efficacy of entomopathogenic nematodes (Nematoda: Rhabditida) and insecticide mixtures to control Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) in corn. Crop Protection. 29: 677-683.
- 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.