Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/1996
Publication Date: N/A
Interpretive Summary: The report provides information on the practical use of sap beetle pheromones for the protection of fruit crops. The sap beetles (family Nitidulidae) are serious pests of peaches and apricots in Australia and also attack a wide variety of fruits and grains in the USA and other parts of the world. Pheromones for these beetles (natural chemicals that the beetles emit to attract others of their kind for reproduction) were previously identified and synthesized by ARS scientists. The pheromones have good potential to be useful and environmentally safe tools for pest management, for example, in mass trapping of the pest species. The present study explores one major consideration in mass trapping: how the traps should be distributed in the crop. The major conclusion was that significant crop protection can be accomplished by mass trapping, but the traps must not be placed too close to the trees to be protected. Location of traps is discussed in relation to other practical factors: trap design, pheromone formulation, and agronomic practices.
Technical Abstract: Experiments in southern New South Wales evaluated the potential of mass-trapping, using synthetic aggregation pheromones and a coattractant as a control option for Carpophilus spp. in stone fruit orchards. A cordon of 108 traps (two per perimeter tree) maintained around an apricot orchard for three weeks prior to harvest and baited with pheromones of C. mutilatus and C. davidsoni and coattractant (fermenting bread dough) significantly reduced the incidence of Carpophilus spp. in ripe fruit in the center of the orchard compared to a nearby orchard or the perimeter trees containing traps. A cordon of 16 similarly baited traps placed around a 9 X 9 block of trees in a peach orchard (single traps on alternate perimeter trees) significantly reduced infestation of fruit baits by Carpophilus spp. in the center tree over a period of six weeks compared to fruit baits in trap trees and distant (100 m) control trees. However, cordons of eight pheromone traps within 1 m of single trees or a single trap adjacent to a tree increased Carpophilus spp. infestation of fruit baits by up to 7.5 X compared to trees without pheromone traps. Mass-trapping based on perimeter positioning of pheromone traps (at a yet to be determined distance from protected trees) appears to show potential as a control strategy for Carpophilus spp. in stone fruit orchards during fruit ripening and harvest, but traps too close to trees must be avoided. Development of a strategy for population suppression is discussed.