Possible use of synthetic aggregation pheromones to control stinkbug Plautia stali in kaki persimmon orchards

1 The brown-winged green stinkbug Plautia stali Scott (Hemiptera: Pentatomidae) is the most serious pest of all noxious stinkbugs in various orchards in Japan. An area-wide integrated pest management programme using the species-specific aggregation pheromone is desirable to control P. stali because nonspecific insecticides may kill arthropod natural enemies and induce the resurgence of other endemic pests. 2 The traditional mass-trapping method is not expected to be effective as a result of huge migrations from cypress forests. Therefore, we chose an 'attract-and-kill' strategy of intensively installing poisonous eggplants with a synthetic aggregation pheromone lure as enclosures for the target orchards. 3 We found no overall control effect of the installation of poisonous eggplants, although regional differences were observed, which might originate from topological configurations or the distance from the source population in cypress forests. 4 The poisonous eggplants with an aggregation-pheromone lure, however, changed the spatial distribution of fruit damage, appearing to induce the majority of the damage within a 100-m range of the poisonous eggplants. Some damage, although at a low level, was found in regions 100-200 m away from the poisonous eggplants. 5 We postulate that such low-damage regions were created because the majority of the bugs dispersed from the centre of the orchards to the areas with poisonous eggplants. The present study, in which the spatial scale of the damage spillover was estimated at approximately 150 m, has important implications for future strategies of attract-and-kill and possibly push-pull.