Cameroon Fly Survey Reveals Distinct Vector Patterns

A longitudinal entomological survey conducted at two livestock research stations in Cameroon has provided the first comprehensive baseline data on the biodiversity and seasonal dynamics of mechanical vectors for African Animal Trypanosomiasis. The study, published in BMC Veterinary Research, assessed the populations of tabanid and stomoxyine flies at the Wakwa Zootechnical Station in the Adamawa region and the Lougguéré Zootechnical Station in the North region. By capturing 1,481 hematophagous dipterans between February and November 2021, the research team identified significant contrasts in species richness and abundance between the two locations, highlighting the complex environmental drivers that influence vector populations in these livestock production systems.

The research was motivated by the persistent challenge of African Animal Trypanosomiasis, a disease that remains a major constraint to livestock productivity in sub-Saharan Africa. Despite the epidemiological importance of these vectors, comprehensive data on their biodiversity and seasonal dynamics at specific livestock production sites in Cameroon had previously been limited.

To address this gap, the researchers employed a standardised array of Nzi, Vavoua, and biconical traps to capture flies over the nine-month survey period. Captured specimens were identified morphologically using standard identification keys, ensuring accurate taxonomic classification. The team calculated the apparent density per trap per day (ADT) to quantify vector abundance and used Margalef’s diversity index to assess species diversity.

The results revealed a total of 1,272 stable flies (Stomoxyinae) and 209 tabanids (Tabanidae). A striking difference in species richness was observed between the two sites: tabanid species richness was substantially higher at Lougguéré, with 10 species recorded, compared to only 4 species at Wakwa. In contrast, stable fly species richness was identical across both sampling locations, with 3 species per station. The most abundant stable fly species was Stomoxys niger niger, accounting for 893 specimens, while Atylotus albipalpus dominated tabanid captures at Lougguéré with 66 specimens.

Seasonal patterns also emerged as a critical factor in vector abundance. To understand the specific environmental drivers, the researchers employed negative binomial regression models, which were selected based on Akaike Information Criterion and Pearson dispersion ratios.

The regression analysis identified distinct primary drivers for each vector group. For tabanids, locality was the only significant predictor of abundance, with the incidence rate ratio (IRR) of 0.044 indicating that tabanid abundance at Wakwa was significantly lower than at Lougguéré (p = 0.0007). In contrast, stable fly abundance was primarily driven by temperature and season. Temperature had a strong positive effect (IRR = 5.766, p < 0.001), while the dry season was associated with lower abundance (IRR = 0.186, p = 0.045). Humidity approached statistical significance for stable flies (IRR = 2.832; p = 0.054), further underscoring the sensitivity of these insects to abiotic conditions.

The presence of confirmed mechanical vector species, specifically Atylotus agrestis and A. fuscipes, at the Lougguéré station underscores the potential for mechanical transmission of trypanosomes in this region. These findings highlight the need for vector-group-specific risk assessments, as the drivers of tabanid and stable fly abundance differ significantly. The contrasting patterns suggest that a one-size-fits-all approach to vector control may be ineffective, and that tailored strategies are required to mitigate the risk of disease transmission in Cameroonian livestock production systems.

This study provides essential baseline data for developing targeted surveillance and integrated vector management programmes. By identifying the specific environmental factors that influence vector abundance, the research offers a foundation for more precise monitoring and control efforts. The distinct biodiversity profiles of the two stations emphasize the importance of localised data in understanding vector-borne disease dynamics.

Subject of Research: Biodiversity and seasonal dynamics of tabanid and stomoxyine flies in Cameroon

Article Title: Biodiversity of tabanids and stomoxys flies at two livestock research stations in Cameroon (Wakwa and Lougguéré)

Article References: Nzeket, R. P. N., Mamoudou, A., Danga, S. P. Y., Abah, S., Sieumeni, A. D., & Nukenine, E. N. (2026). Biodiversity of tabanids and stomoxys flies at two livestock research stations in Cameroon (Wakwa and Lougguéré). BMC Veterinary Research. https://doi.org/10.1186/s12917-026-06025-2

Image Credits: AI Generated

DOI: 10.1186/s12917-026-06025-2

Keywords: African Animal Trypanosomiasis, Tabanidae, Stomoxyinae, Vector-borne diseases, Cameroon, Livestock research, Entomology, Seasonal dynamics, Mechanical transmission, Biodiversity, tabanids, stomoxys