Pheromone‐mediated mass trapping and population diversion as strategies for suppressing Carpophilus spp. (Coleoptera: Nitidulidae) in Australian stone fruit orchards

Abstract

Summary1 Five experiments were conducted during 1995–99 in stone fruit orchards on the Central Coast and in inland New South Wales, Australia, on the use of synthetic aggregation pheromones and a coattractant to suppress populations of the ripening fruit pests Carpophilus spp. (Coleoptera: Nitidulidae).2 Perimeter‐based suppression traps baited with pheromone and coattractant placed at 3 m intervals around small fruit blocks, caught large numbers of Carpophilus spp. Very small populations of Carpophilus spp. occurred within blocks, and fruit damage was minimal.3 Carpophilus spp. populations in stone fruit blocks 15–370 m from suppression traps were also small and non‐damaging, indicating a large zone of pheromone attractivity.4 Pheromone/coattractant‐baited suppression traps appeared to divert Carpophilus spp. from nearby (130 m) ripening stone fruit. Ten metal drums containing decomposing fruit, baited with pheromone and treated with insecticide, attracted Carpophilus spp. and appeared to reduce populations and damage to ripening fruit at distances of 200–500 m. Populations and damage were significantly greater within 200 m of the drums and may have been caused by ineffective poisoning or poor quality/overcrowding of fruit resources in the drums.5 Suppression of Carpophilus spp. populations using synthetic aggregation pheromones and a coattractant appears to be a realistic management option in stone fruit orchards. Pheromone‐mediated diversion of beetle populations from ripening fruit may be more practical than perimeter trapping, but more research is needed on the effective range of Carpophilus pheromones and the relative merits of trapping compared to attraction to insecticide‐treated areas.

An attract‐and‐kill system to control Carpophilus spp. in Australian stone fruit orchards

“…Whereas, in our study, we used fermenting peach nectar in addition to ripening peaches as co‐attractant, and this was replaced with new fruit and fermenting peach nectar every week. It is possible that the attract‐and‐kill stations used by James et al. (2001) with rotting fruit were not as effective as those used in our study.…”

“…Insufficient orchards were available to conduct such experiments. One of the main differences between this experiment and that of James et al. (2001) is that in our experiment, the attract‐and‐kill stations were deployed well before fruit ripening started.…”

“…populations sufficiently to prevent damage to ripening fruit. James et al. (2001), published after we designed our experiments, developed a similar suggestion.…”

“…in fruit on the trees in which the traps were hung. To improve control in the perimeter trees, James et al. (2001) used attract‐and‐kill stations containing decomposing stone fruit as co‐attractant plus aggregation pheromones, placed in an open area in the centre of an orchard, instead of perimeter traps.…”

“…in fruit on the trees in which the traps were hung. To improve control in the perimeter trees, James et al (2001) used attract-and-kill stations containing decomposing stone fruit as co-attractant plus aggregation pheromones, placed in an open area in the centre of an orchard, instead of perimeter traps. The percentage of damaged fruit (44%) within 200 m of the pheromone source was significantly greater than in trees located further (200 -500 m) away from the pheromone source (14%).…”