Aromatherapy on a large scale: exposing entire adult holding rooms to ginger root oil increases the mating competitiveness of sterile males of the Mediterranean fruit fly in field cage trials

Abstract

The sterile insect technique (SIT) is widely used in integrated programs against fruit fly pests, particularly the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Unfortunately, the mass‐rearing procedures inherent to the SIT often lead to a reduction in male mating competitiveness. One potential solution involves the pre‐release exposure of males to specific attractants. In particular, male exposure to ginger root oil [Zingiber officinale Roscoe (Zingiberaceae); hereafter GRO] has been shown to increase mating success dramatically in field cage trials. Initial studies exposed small groups of males (25 individuals), but more recent work has demonstrated that GRO exposure involving standard storage boxes (containing ≈ 36 000 males) also results in enhanced mating performance. The objective of the present study was to determine whether aromatization of entire trailers, holding ≈ 14 million sterile males from a genetic sexing [temperature sensitive lethal (tsl)] strain, increases male mating success. Independent of the total dose, spatial distribution, or type of dispenser used, sterile males exposed to GRO for a 24‐h period displayed greater mating success than non‐exposed males in mating cage trials (in which tsl males competed against males from a standard, bisexual strain for females from this same standard strain). Averaged over all experiments, tsl males exposed to GRO obtained 54% of all matings compared to 38% for non‐exposed tsl males, an increase of 42%. The implications of these findings for SIT programs against C. capitata are discussed.

Improving an adult holding system for Mediterranean fruit fly, Ceratitis capitata, to enhance sterile male performance

“…The competitiveness of sterile males, and their ability to mate with wild females, was increased by exposing them to GRO aromatherapy the day before release. These results are in line with the recent published literature on the positive impact of GRO aromatherapy on male sexual performance (Shelly et al. 2004, 2007) and on the lack of negative impact on field survival (Paranhos et al.…”

Optimum dose of ginger root oil to treat sterile Mediterranean fruit fly males (Diptera: Tephritidae)

“…The amount of GRO used depends on the size of the room and the number of flies to be exposed. As little as 20 ml of GRO has been successfully used to expose up to 10–12 million males overnight in large shipping trailers (∼132 m 3 ) in the California sterile C. capitata preventive release programme (Shelly et al. 2007a).…”

Morphological characterization of the antennal lobes in the Mediterranean fruit fly Ceratitis capitata

“…In females, odor preference may be affected by mating behavior: it has been observed that females are more attracted by the male-produced pheromone than the ripe guava odor during early sexual maturity, but this preference is inverted after mating (Jang 1995). Furthermore, the exposure to some natural and synthetic compounds may influence the mating behavior in medfly males (Shelly et al 1996(Shelly et al , 2004(Shelly et al , 2007(Shelly et al , 2008.…”