Archive

Biological control of slugs and snails with parasitic nematode, Phasmarhabditis hermaprodita

• Slugs (Mollusca: Gastropoda) are considered as important pests of many agricultural and horticultural crops throughout the world.
• Recently, a slug parasitic nematode, P. hermaprodita has been commercialized as a biological molluscicide by MicroBio Ltd, UK and sold under the trade name “Nemaslug”.
• Phasmarhabditis hermaprodita as been found to be associated with several different bacteria rather than one particular species but the association with a bacterium, Moraxella oslensis proved to be highly pathogenic to gray garden slug (Deroceras reticulatum) and preferred bacterium for mass production of this nematode in monoxenic culture.
• Like entomopathogenic nematodes, slug parasitic nematode infective juveniles or dauer juveniles move through soil, locate slugs and infect.  They penetrate slugs through a natural opening at the backside of the mantle. Once inside, the dauer juveniles release bacterial cells, start feeding on multiplying bacteria and develop into self-fertilizing hermaphrodites. Nematode- bacteria complex can cause the death of the slug within 7-21 days after infection.
• Phasmarhabditis hermaprodita can attack and kill several species of slugs including Arion ater, A. intermedius, A. distinctus, A. silvaticus, D. reticulatum, D. caruanae, Tandonia budapestensis and T. sowerbyi.
• Phasmarhabditis hermaprodita can also parasitize several species of snails including Cernuella virgata, Cochlicella acuta, Helis aspersa, Monacha cantiana, Lymnaea stagnalis and Theba pisana.
• It has been demonstrated that slug parasitic nematodes when applied at the rate of 3x 109 infective juveniles/hectare can give better control of slugs than standard chemical molluscicide, Methiocarb pellets.
• For more information on insect and slug parasitic nematodes read a book “Nematodes As Biocontrol Agents” by Grewal, P.S. Ehlers, R.-U., Shapiro-Ilan, D. (eds.). CAB publishing, CAB International, Oxon.
  

Species of white grubs : Species of entompathogenic nematodes

1. Asiatic garden beetle (Maladera castanea): H. bacteriophora, S. glaseri, S. scarabae
2. Black turfgrass ataenius (Ataenius spretulus): H. bacteriophora, S. glaseri, S. scarabae
3. Cockchafer (Melolontha melolontha): H. bacteriophora, H. marelata, H. megidis, S arenaria, S. feltiae, S. glaseri, S. riobrave
4. Cranberry root grub (Phyllophaga Georgiana): H. bacteriophora, S. glaseri, S. scarabae
5. European chafer (Rhizotrogus majalis): H. bacteriophora, H. megidis, H. zealandica, S. carpocapsae, S. feltiae, S. glaseri, S. scarabae
6. Grass grub beetle (Costelytra zealandica): H. bacteriophora, S. glaseri
7. Green June beetle (Cotinus nitida): H. bacteriophora, S. carpocapsae, S. feltiae, S. glaseri, S. scarabae
8. Japanese beetle (Popillia japonica): H. bacteriophora, H. indica, H. marelata, H. megidis, H. zealandica, S. anomali, S. carpocapsae, S. feltiae, S. glaseri, S. kushidai, S. riobrave, S. scapterisci, S. scarabae
9. Masked Chafer (Cyclocephala pasadenae): H. bacteriophora, S. glaseri, S. kushidai, S. scarabae
10. Northern Masked Chafer (Cyclocephala borealis): H. bacteriophora, H. indica, H. marelata, H. megidis, H. zealandica, S. glaseri, S. scarabae
11. Oriental beetle (Anomala orientalis): H. bacteriophora, H. megidis, H. zealandica, S. carpocapsae, S. glaseri, S. longicaudum, S. scarabae
12. Southern Masked Chafer (Cyclocephala lurida): H. bacteriophora, S. glaseri, S. scarabae
13. Southwestern Masked Chafer (Cyclocephala hirta): H. bacteriophora, H. megidis, S. carpocapsae, S. feltiae, S. glaseri, S. kushidai, S. riobrave, S. scarabae
14. Summer chafer (Amphimallon solstitiale): S. glaseri
15. White grub (Hoplia philanthus): H. megidis, S. feltiae, S. glaseri
16. White grub (Phyllophaga crinita): H. bacteriophora, S. glaseri, S. scarabae
17. White grub (Phyllophaga congrua): H. bacteriophora, S. glaseri, S. scarabae

For more information on insect pathogenic nematodes read book “Nematodes As Biocontrol Agents” by Grewal, P.S. Ehlers, R.-U., Shapiro-Ilan, D. (eds.). CAB publishing, CAB International, Oxon.