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

Abstract

The success of using the sterile insect technique (SIT) for Mediterranean fruit fly, Ceratitis capitata (Wiedemann), suppression programmes is dependent on the release into the field of sterile males that survive and compete successfully with wild males for matings with wild females. The effects of pre‐release aromatherapy using ginger root oil (GRO) and the addition of hydrolysed yeast (protein and other nutrients) to the fly diet, on sterile male dispersal, survival, sexual maturation and mating performance under laboratory and field conditions were evaluated. The interaction between providing protein and/or GRO treatment was also evaluated. Under field cage conditions, male mating performance was significantly higher in treatments with GRO but was unaffected by the provision of protein. There was no interaction between them. However, after releases under field conditions, survival of protein‐fed sterile males was significantly longer compared with protein‐deprived sterile males. The use of GRO should be incorporated into the sterile male–handling protocol for SIT programmes. In combination with the validation of the provision of these supplements, two new cage systems developed in the Madeira‐Med Programme were tested in comparison with the standard plastic adult rearing containers boxes for a more cost‐effective sterile male emergence, feeding, holding and collecting process at fly emergence and release facilities. This selected cages systems can handle approximately 1 million pupae and reduces manual labour and other costs while maintaining good sterile male quality.

Towards improving sterile insect technique: Exposure to orange oil compounds increases sexual signalling and longevity in Ceratitis capitata males of the Vienna 8 GSS

“…In this study, adult medflies were in direct contact with the tested compounds (citrus oils were topically applied to the thorax of medflies), and any comparisons between the two studies are hard to make. Enhancing survival in male medflies under field conditions has also been demonstrated after exposure to ginger root oil [ 43 ], yet it is not clear if this arises from prolonged longevity per se of those males or as a side-effect of improving other traits in those males that could ultimately lead to increased longevity (e.g. greater ability to find natural sources of nutrition after release, see in [ 44 ]).…”

Different methods of methyl eugenol application enhance the mating success of male Oriental fruit fly (Dipera: Tephritidae)

“…The system that is routinely used in Mediterranean fruit fly Ceratitis capitata (Wiedemann) SIT programmes to increase mating success of sterile males 29 , 34 consists of blowing a mist of volatiles of ginger root oil (GRO) into the sterile male holding rooms. This method of ‘aromatherapy’ allows sexually mature males to obtain access to GRO through condensation, inhalation, or impregnation with the chemicals in the circulating air prior to their release in the field 35 – 37 . ‘Aromatherapy’ was first used by Shelly et al .…”

Improving sterile male performance in support of programmes integrating the sterile insect technique against fruit flies

“…Positive effects of OO in protein-sugar diet were found, but no effects in the sugar-only diet Improving sterile male performance in fruit fly SIT R. Pereira et al The cost-effective GRO exposure to sterile males established and now in operational used in a number of C. capitata SIT action programmes (Shelly et al 2007b(Shelly et al ,c, 2008aParanhos et al 2008Paranhos et al , 2013JuanBlasco et al 2013;Silva et al 2013;Steiner et al 2013) sexing strains, the release of older males is preferable resulting in more flies reaching mating age in the field ) Species with longer pre-copulatory period would benefit more from longer pre-release holding periods Pereira et al 2013) Design for a fly holding system that optimizes methyl eugenol feeding and fly holding in space and time was completed for Bactrocera dorsalis. Preliminary tests on interactions of males with the semiochemical feeding structure were tested in a small-scale prototype (Tan and Tan 2013b) Comparison of males from standard conditions with males pre-conditioned to specific field conditions Pre-conditioning of sterile males to specific field conditions was assessed in Bactrocera tryoni and C. capitata for temperature Effects of cold knockdown Effect of cold knockdown varies with C. capitata density.…”

“…The effects on fly performance of different sterile fly release systems, and the interaction with hormonal, nutritional and/or semiochemical supplements was assessed for some aerial and ground release systems for C. capitata in terms of dispersal and recapture Silva et al 2013) Hormonally and nutritionally treated A. ludens and A. obliqua released by air were evaluated in terms of quality and field survival Ground release machine was developed and evaluated Comparison of different alternative aircrafts was carried out in terms of their suitability and economics for sterile fly aerial release (Tan and Tan 2013a) into a manual, have benefited all operational fruit fly SIT programmes. Knowledge gained and practical procedures developed during this CRP are transferable, at least in part, to other insect pest species with control programmes that include an SIT component.…”