Acceptability of clover flea as prey for common pasture spiders

Abstract

Clover flea (Sminthurus viridis) is present throughout New Zealand causing significant damage to white clover (Trifolium repens) in localised areas of the North Island Insecticides are available for clover flea control but their use is harmful to beneficial pasture invertebrates While predatory mites are present in New Zealand pastures previous research has indicated that they are relatively ineffective at moderating clover flea populations Other species in pasture such as spiders may prove to be more effective predators The feeding and survival of clover flea was compared when caged with common pasture spiders (Lycosidae or Linyphiidae) at either 15C or 20C Spiders had a significant effect on clover flea survival and there was no difference between spider families At 15C clover flea survival in the presence of spiders was less than 21 compared with 94 survival in the spiderfree controls (P<0001) At 20C clover flea survival was further reduced to 12 compared with 41 in the controls (P<0001) Clover flea feeding scores were significantly lower when caged with spiders (P<0001) There were no feeding differences between spider families or temperatures This work highlights the role beneficial invertebrates can play in controlling pest abundance and damage