An effective synthetic attractant, based on host-related volatile compounds, was developed for the nitidulid beetle, Carpophilus davidsoni, as part of a program for managing this pest in Australian peach orchards. Fermenting peach juice and whole peaches and nectarines served as chemical models for the attractant, and synthetic formulations were sought that matched the natural sources, both with respect to emission rates of key chemicals (in ng/min) and attractiveness to flying beetles. All volatile sources were kept in airstreams during laboratory chemical measurements, and these airstreams were subsequently directed to the wind-tunnel behavioral assay, allowing the determined emission rates of compounds to be associated with particular levels of attractiveness. Chemical sampling of airstreams was by solid-phase microextraction, and analysis was by gas chromatography and mass spectrometry. A volatile delivery system was coupled to the wind tunnel and allowed facile manipulation of natural and synthetic scents. The final blend, modeled after fermenting peach juice, contained ethanol as the main constituent and 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, acetaldehyde, and ethyl acetate as minor constituents, all in water solution. Blend components were synergistic, and use of a mixture was essential for optimal attractiveness. The synthetic blend was highly effective in the field and is intended to replace fermenting peach juice and overripe peaches, which were previously used as synergists of the Carpophilus spp. aggregation pheromones in attract-and-kill stations.

During two growing seasons, the use of an attract‐and‐kill system for control of Carpophilus spp. (Coleoptera: Nitidulidae) and the effective range or drawing power of the attract‐and‐kill stations were examined in stone fruit orchards in the Goulburn Valley, northern Victoria, Australia. Three attract‐and‐kill stations, baited with synthetic aggregation pheromone plus co‐attractant, were placed about 50 m apart in the upwind corner of each treated block 5–6 weeks before the fruit began to ripen. Large numbers of Carpophilus spp. were caught in the attract‐and‐kill stations immediately after placement. By the time fruit had ripened, the number of Carpophilus spp. caught had decreased greatly. Fruit damage caused by Carpophilus spp. in treated blocks, especially in 2000–2001 season, was almost zero (0.1% and 0.6%) in trees and on the ground, respectively, whereas the damage levels in control blocks were 5.2% and 19.9% in trees and on the ground, respectively. This study indicates that excellent protection of ripening stone fruit may be achieved by using attract‐and kill‐stations.

No abstract

Three field experiments were conducted in stone fruit orchards in the Goulburn Valley, northern Victoria, Australia to identify a user-friendly trap for use in attract and kill stations for control of Carpophilus spp. (Coleoptera: Nitidulidae). A funnel trap design was compared with two types of delta trap in one experiment and two types of Lucitrap in another experiment. All traps were baited with synthetic co-attractant and synthetic pheromone. The funnel trap was the most effective type of trap tested. The funnel traps caught significantly more beetles than either the delta traps with bio-attractant or delta traps wrapped with insecticide impregnated banana wrap. No difference was observed between catches in either delta trap design. Lucitraps without covers caught significantly more beetles than Lucitraps with covers but funnel traps caught significantly more beetles than either type of Lucitrap. Beetle numbers caught in the funnel traps were three to five times higher than in Lucitrap. The use of funnel traps in attract and kill stations to protect stone fruit crops by suppressing the Carpophilus spp. population gave superior control to 'grower normal practice of spraying insecticides' both in terms of Carpophilus spp. numbers and in terms of reduction in percentage of fruit damaged.

Nitidulid beetles of the genus Carpophilus are significant pests of a wide variety of fruits and grains and are also vectors of harmful microorganisms. The beetles are difficult to control with conventional insecticides because the beetle damage typically occurs just before harvest, when toxic residues must be avoided. These insects are generally attracted to scents such as from overripe or decomposing fruit. Starting in the 1960's, research was done to develop fermenting fruit and similar materials as trap baits, initially with the intent of achieving beetle control. These studies provided much new information about the ecology and chemistry of host location, but they did not prove successful in protecting crops from beetle damage. Beginning in the late 1980's, pheromones were discovered in Carpophilus beetles. These were potent, male-produced aggregation pheromones, and over the next 20 years much new information was gained about their ecological properties, physiology, and novel chemistry. Importantly, the pheromones were strongly synergistic with fermenting host odors, and the combination was far more attractive than fruit-related baits or pheromones alone, which greatly improved the ability to attract these pests to traps. A practical attract-and-kill method using the pheromones and host volatiles has been developed in Australia and shown to be at least as effective as insecticides for protecting stone fruit crops.