Spatio-temporal optimization of sampling for bluetongue vectors (Culicoides) near grazing livestock

Particle and Fibre Toxicology

Peter Lind²  René Bødker²  Anders Stockmarr¹  Carsten Kirkeby² 

[1]Department of Applied Mathematics and Computer Science, DTU Compute, Technical University of Denmark.Matematiktorvet, Building 324, DK-2800 Lyngby, Denmark

[2]National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, DK-1790 Copenhagen V, Denmark

关键词: Bluetongue;    Abundance;    Light traps;    Spatial variation;    Culicoides obsoletus;   

Others  :  1227949
DOI  :  10.1186/1756-3305-6-151

 received in 2013-02-05, accepted in 2013-05-12,  发布年份 2013

【 摘 要 】

Background

Estimating the abundance of Culicoides using light traps is influenced by a large variation in abundance in time and place. This study investigates the optimal trapping strategy to estimate the abundance or presence/absence of Culicoides on a field with grazing animals. We used 45 light traps to sample specimens from the Culicoides obsoletus species complex on a 14 hectare field during 16 nights in 2009.

Findings

The large number of traps and catch nights enabled us to simulate a series of samples consisting of different numbers of traps (1-15) on each night. We also varied the number of catch nights when simulating the sampling, and sampled with increasing minimum distances between traps. We used resampling to generate a distribution of different mean and median abundance in each sample. Finally, we used the hypergeometric distribution to estimate the probability of falsely detecting absence of vectors on the field. The variation in the estimated abundance decreased steeply when using up to six traps, and was less pronounced when using more traps, although no clear cutoff was found.

Conclusions

Despite spatial clustering in vector abundance, we found no effect of increasing the distance between traps. We found that 18 traps were generally required to reach 90% probability of a true positive catch when sampling just one night. But when sampling over two nights the same probability level was obtained with just three traps per night. The results are useful for the design of vector monitoring programmes on fields with grazing animals.

【 授权许可】

   
2013 Kirkeby et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

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