|Vetter Richard S,|
|Carlson Diana G,|
|Baker Thomas C,|
Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 28, 1995
Publication Date: N/A
Interpretive Summary: Sap beetles (family Nitidulidae) are worldwide pests of fruits and grains such as figs, dates, and corn. Attack typically occurs as the crop ripens; control is difficult because insecticide residues must be avoided as the crop is harvested. Pheromones (natural attractants that insects use to locate other individuals of the same species) are now known for a number of major sap beetle species. These alternatives may provide means of control in the future, such as by mass trapping and would reduce the need for insecticides. Unfortunately, there is usually a complex of sap beetle species attacking a crop, each with a unique pheromone. One could envision the need to deal separately with a number of sap beetle species in pheromonally based pest management. However, this research demonstrated that the pheromones for three of the major sap beetle species attacking California dates can be combined into a single lure with little or no loss of attractiveness for any of the species. A "universal" sap beetle lure seems possible in concept and would greatly simplify future practical use of the pheromones.
Technical Abstract: Combinations of aggregation pheromones for three nitidulid beetle species, Carpophilus hemipterus (L.), C. mutilatus Erichson, and C. freemani Dobson, were evaluated as trap baits in a date garden in southern California. All possible two-way and three-way combinations were compared against the single pheromones; the pheromone treatments were synergized by fermenting whole-wheat bread dough, and dough by itself was the experimental control. For each species, every treatment containing its pheromone was significantly more attractive than the control. Furthermore, these combinations tended to be similar in activity to the most attractive single pheromone contained in it; for example, C. hemipterus and C. mutilatus responded at least as well to the three-pheromone combination as to the respective separate pheromones. Only for C. freemani was the three-pheromone combination somewhat less attractive than the species' pheromone tested alone. Two other species, C. obsoletus Erichson and C. (Urophorus) humeralis (F.), were present at the test site in smaller numbers. These exhibited significant cross attraction to the pheromones of the major species, especially C. hemipterus, and for these minor species also, the pheromone combinations were at least as effective as the individual pheromones. For all species, males and females responded in similar numbers. The pheromone combinations would greatly simplify using the pheromones in pest management (e.g., in mass trapping). A single, multi- species lure could be used instead of a series of individual pheromone lures, and little or no efficacy for the target species would be lost.