Y. Nakache
The Red Palm Weevil (RPW) Rhynchophorus ferrugineus (Olivier) is one of the most serious invasive pests of different palm species, including dates. Management of the RPW is problematic due to its cryptic behavior which makes it difficult to detect and control. A major route of RPW spread is via the transportation of infested planting material to new locations before the first detectable symptoms of infestation appear. It is thus imperative to develop methods and protocols for the generation of pest-free planting. The goals of this project were: to develop an acoustic based weevil detection technique and a fumigation protocol for potentially infested planting material. To address these objectives, laboratory studies were conducted under quarantine conditions. Date palm offshoots of up to 6–14 cm diameter were artificially infested with one or two 2–3rd instar larvae (20–30 mg) that were allowed to develop for various periods. Development of the larvae inside the tree trunk was monitored acoustically once a week. The effect of methyl bromide fumigation (MeBr) was tested at several doses (10, 20, 30, and 40 g/m3 ) on plants infested with various weevil instars: larvae, pupae, and pharate adult. At all doses, groups of trees were exposed to MeBr treatment in gas tight dedicated chamber for 4 hours. For g/m3 , the efficacy of 4- and 8-hour fumigation was compared. A day after treatment the trees were dissected to evaluate treatment success. The fumigation with 20–40 mg/m3 for 4 hour and 10 mg/m3 for 8 hour proved effective in killing 100% of the weevils within the shoot. The acoustic algorithm was able to detect active weevils with an accuracy of 97–98%. We anticipate that acoustic instrumentation and improved signal processing software will be used frequently in the future as part of a monitoring program to screen transported material.
Y. Nakache
The Red Palm Weevil (RPW) Rhynchophorus ferrugineus (Olivier) is one of the most serious invasive pests of different palm species, including dates. Management of the RPW is problematic due to its cryptic behavior which makes it difficult to detect and control. A major route of RPW spread is via the transportation of infested planting material to new locations before the first detectable symptoms of infestation appear. It is thus imperative to develop methods and protocols for the generation of pest-free planting. The goals of this project were: to develop an acoustic based weevil detection technique and a fumigation protocol for potentially infested planting material. To address these objectives, laboratory studies were conducted under quarantine conditions. Date palm offshoots of up to 6–14 cm diameter were artificially infested with one or two 2–3rd instar larvae (20–30 mg) that were allowed to develop for various periods. Development of the larvae inside the tree trunk was monitored acoustically once a week. The effect of methyl bromide fumigation (MeBr) was tested at several doses (10, 20, 30, and 40 g/m3 ) on plants infested with various weevil instars: larvae, pupae, and pharate adult. At all doses, groups of trees were exposed to MeBr treatment in gas tight dedicated chamber for 4 hours. For g/m3 , the efficacy of 4- and 8-hour fumigation was compared. A day after treatment the trees were dissected to evaluate treatment success. The fumigation with 20–40 mg/m3 for 4 hour and 10 mg/m3 for 8 hour proved effective in killing 100% of the weevils within the shoot. The acoustic algorithm was able to detect active weevils with an accuracy of 97–98%. We anticipate that acoustic instrumentation and improved signal processing software will be used frequently in the future as part of a monitoring program to screen transported material.