Competitiveness and survival of two strains of Glossina palpalis gambiensis in an urban area of Senegal

PLoS Negl Trop Dis. 2017 Dec 27;11(12):e0006172. doi: 10.1371/journal.pntd.0006172. eCollection 2017 Dec.

Abstract

Background: In the Niayes area, located in the west of Senegal, only one tsetse species, Glossina palpalis gambiensis Vanderplank (Diptera: Glossinidae) was present. The Government of Senegal initiated and implemented an elimination programme in this area that included a sterile insect technique (SIT) component. The G. p. gambiensis strain (BKF) mass-reared at the Centre International de Recherche-Développement sur l'Elevage en zone Subhumide (CIRDES) in Burkina Faso was used for the SIT component.

Methodology/principal findings: Studies conducted in 2011 in four localities in the Niayes area (Pout, Sébikotane, Diacksao Peul and the Parc de Hann) showed that the BKF strain demonstrated inferior survival in the ecosystem of the Parc de Hann, a forested area in the city centre of the capital Dakar. Therefore, G. p. gambiensis flies from the Niayes area (SEN strain) were colonized. Here we compared the competitiveness and survival of the two strains (BKF and SEN) in the Parc de Hann. Released sterile males of the SEN colony showed a daily mortality rate of 0.08 (SD 0.08) as compared with 0.14 (SD 0.08) for the BKF flies but the difference was not significant (p-value = 0.14). However, the competitiveness of the SEN males was lower (0.14 (SD 0.10)) as compared with that of the BKF males (0.76 (SD 0.11)) (p-value < 10-3).

Conclusions/significance: Based on the results of this study, it can be concluded that the BKF strain will remain the main strain to be used in the elimination programme. Despite the slightly longer survival of the SEN males in the Parc de Hann, the superior competitiveness of the BKF males is deemed more important for the SIT component, as their shorter survival rates can be easily compensated for by more frequent fly releases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Control Agents*
  • Female
  • Infertility, Male / genetics*
  • Insect Control / methods*
  • Insect Vectors / growth & development
  • Insect Vectors / virology
  • Male
  • Senegal
  • Tsetse Flies / genetics
  • Tsetse Flies / growth & development*

Substances

  • Biological Control Agents

Grants and funding

This work was funded by the US State Department through the Peaceful Uses Initiative, the Joint Food and Agriculture Organization of the United Nations/International Atomic Energy Agency Division of Nuclear Techniques in Food and Agriculture, the Department of Technical Cooperation, the Directorate of Veterinary Services of Sénégal, the Institut Sénégalais de Recherches Agricoles, and Centre de Coopération Internationale en Recherche Agronomique pour le Développement. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.