The Ethics of Eliminating Harmful Species: The Case of the Tsetse Fly

Abstract

Wildlife species harmful to humans are often targets of control and elimination programs. A contemporary example is the tsetse fly, a vector of sleeping sickness and African animal trypanosomosis. Tsetse flies have recently been targeted by a pan-African eradication campaign. If it is successful, the campaign could push the entire tsetse family to extinction. With the emergence of effective and efficient elimination technologies, ethical assessment of proposed elimination campaigns is urgently needed. We examine the ethics of tsetse fly elimination by considering arguments predicated on both the instrumental and the intrinsic values of the species at local and global scales. We conclude that, although global eradication of tsetse flies is not ethically justified, localized elimination campaigns targeting isolated populations are ethically defensible. We urge assessments of this kind be conducted regularly and in context, so that all relevant factors underlying decisions on species elimination are routinely laid bare for evaluation.

The impact of vector migration on the effectiveness of strategies to control gambiense human African trypanosomiasis

“…Therefore, identifying migration corridors into g-HAT foci and targeting them for vector control would be paramount for optimizing the effectiveness of control efforts for interrupting g-HAT transmission [25,53]. In addition to insecticide treated targets and traps, other vector control methods such as sterile insect technique (SIT) has been successfully used for tsetse control/eradication [12,54]. SIT is regarded as the technique with all necessary “qualities” for tsetse species elimination, because its efficiency increases as the density of the targeted population decreases [54,55].…”

“…In addition to insecticide treated targets and traps, other vector control methods such as sterile insect technique (SIT) has been successfully used for tsetse control/eradication [12,54]. SIT is regarded as the technique with all necessary “qualities” for tsetse species elimination, because its efficiency increases as the density of the targeted population decreases [54,55]. However, there are a number of limitations/disadvantages to SIT: i) SIT is a costly, logistically challenging and management intensive method for tsetse species control [54,55]; ii) suppression of tsetse populations using conventional methods may be needed before SIT can be used to eradicate residual populations [55]; and iii) the efficacy of SIT for eradicating tsetse in areas with multiple species remains uncertain.…”

Environmental impact of tsetse eradication in Senegal

“…Bouyer et al . recently discussed ethical considerations on the desirability of the eradication of harmful species 35 and, considering both intrinsic and instrumental values of tsetse, they suggested that it is ethically defensible to eliminate isolated populations that are main vectors of disease for humans and their domestic animals, such as the G. p. gambiensis population targeted in this project 36,37 . The sustained removal of isolated populations of tsetse will only have very limited impact on this tsetse species, which is infesting more than 100,000 km 2 in Senegal, and much larger areas in West-Africa 36 .…”

Human African trypanosomiasis: current status and eradication efforts

“…Furthermore, tsetse control is species-specific to tsetse and does not negatively impact the environment since tsetse are not a key species in the food chain. Therefore, it can be considered ethically defensible, as human deaths are averted [65]; the objective is for local reduction of tsetse in HAT foci to interrupt transmission, rather than global eradication of the fly [66].…”