Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590952
Title: Studies of the slug parasitic nematode Phasmarhabditis hermaphrodita
Author: Rae, R.
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 2007
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Abstract:
The slug parasitic nematode Phasmarhabditis hermaphrodita is a lethal parasite of several slug species and has been formulated into a biological agent for farmers and gardeners. The potential effect of P. hermaphrodita to non-target organisms such as earthworms was investigated. P. hermaphrodita did not cause mortality to the earthworms and is a host specific molluscan parasite. In further studies P. hermaphrodita was shown to utilise earthworms to increase dispersal in soil columns. The response of P. hermaphrodita to an array of slug cues was assessed. The nematode responded well to slug mucus (foot and mantle) and faeces but responded weakly to volatile cues. Further experiments exposed P. hermaphrodita to mucus from different molluscan hosts. The nematode responded best to Arion subfuscus but the reasons for this were not discovered. The slug species Deroceras reticulatum, Milax gagates and Limax pseudoflavus were exposed to P. hermaphrodita. D. reticulatum and M. gagates were highly susceptible to P. hermaphrodita and feeding was strongly inhibited. L. pseudoflavus was not suscepticble to the nematode and did not exhibit signs of feeding inhibition. Nematodes were found in the shell of L. pseudoflavus which may be a defence mechanism to encapsulate invading parasites. Bacterial communities inside P. hermaphrodita grown on different slug species were profiled using PCR and DGGE. P. hermaphrodita did not associate exclusively with one bacterium but with an array of bacterial species. Each profile was different with each batch of nematodes. Field trials were conducted to test novel application strategies aimed at reducing cost of application and decreasing the numbers of nematodes applied. Three applications of 5 nematodes per cm-2 applied at fourteen day intervals reduced slug damage on day 14, 28 and 35. Dipping of the root plug into a nematode and adhesive agent as well as spraying around plant bases also reduced slug damage.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.590952  DOI: Not available
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