Effects of the nematode Phasmarhabditis hermaphrodita and of venom from the endoparasitic wasp Pimpla hypochondriaca on survival and food consumption of the pest slug Deroceras reticulatum; implications for novel biocontrol strategies

• Published in: Pest management science Vol. 64; no. 7; pp. 711 - 719
• Main Authors: Richards, Elaine H, DeMarzo, Damian, Port, Gordon R, Dani, M. Paulina, Walters, Keith FA
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-07-2008; Wiley; Wiley Subscription Services, Inc
• Subjects: Animals; Biological and medical sciences; biological control; biological control agents; Control; Crops, Agricultural - economics; Deroceras reticulatum; Diet; Eating; endoparasites; Fundamental and applied biological sciences. Psychology; Gastropoda - cytology; Gastropoda - drug effects; Gastropoda - parasitology; Gastropoda - physiology; ingestion; Insect control; Insects; mortality; Nematoda; nematode; nematode infections; Nematodes; new methods; Pest control; Pest Control, Biological; Phasmarhabditis hermaphrodita; Phytopathology. Animal pests. Plant and forest protection; Pimpla; Pimpla hypochondriaca; plant pests; Protozoa. Invertebrates; Rhabditoidea - drug effects; Rhabditoidea - physiology; slugs; Survival; Toxins; venom; venoms; Wasp Venoms - pharmacology; Wasps - metabolism; Endoparasite; nematode; Insecta; Biological control; Biological agent; Deroceras reticulatum; Gastropoda; Survival; Limacidae; Pest; Pulmonata; Food intake; Pimpla hypochondriaca; Arthropoda; Venom; Helmintha; Nemathelminthia; Ichneumonidae; Hymenoptera; Invertebrata; Mollusca; Nematoda; Rhabditidae
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.1546

BACKGROUND: Controlling pests through disruption of biochemical pathways by physiologically active compounds/factors from animals and plants represents an expanding field of research. The authors investigated whether such factors in venom from the wasp Pimpla hypochondriaca (Retzius) can affect the viability and food consumption of the slug Deroceras reticulatum (Müller), and whether they can improve the efficacy of nematode-induced slug mortality.RESULTS: Exposure of slugs to 4 mL of water containing 500, 1000 and 5000 Phasmarhabditis hermaphrodita (Schneider) resulted in significant increases in mortality (with hazard ratios of 3.5, 3.9 and 5.8 respectively) and significant reductions in total food consumption and mean food consumption each day for 21 days. Injection of slugs with 4, 8 or 12 μL of P. hypochondriaca venom resulted in significant increases in mortality (with hazard ratios of 3.3, 4.5 and 9.0 respectively) and significant reductions in total food consumption compared with the controls. However, there was no significant effect of venom on the mean food consumption on individual days of the 21 day assay period, although significant reductions occurred for the 8 and 12 μL doses up to day 10. Injecting slugs with 4 μL of venom prior to exposure to 500 nematodes had no synergistic effect on either mortality or food consumption compared with either of the individual treatments.CONCLUSIONS: Pimpla hypochondriaca venom contains factors capable of killing and reducing food consumption by D. reticulatum. The utilization of these factors as components of integrated pest management strategies is discussed. © Crown copyright 2008. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.