Evaluation of sequential sampling plans for estimation of leafmines density of Liriomyza sativae Blanchard (Diptera: Agromyzidae) in cucumber greenhouses

Abstract

This study was conducted to develop sequential sampling plans to estimate leafmine density by Liriomyza sativae (Blanchard) at two fixed-precision levels in a cucumber greenhouse. The within-greenhouse spatial patterns of leafmines were aggregated. The slopes and intercepts of Taylor’s power law did not differ between years. A fixed-precision level sampling plan was developed using the parameters of Taylor’s power law generated from total number of leafmines in a cucumber leaf at two precision levels (D) of 0.1 and 0.25. The resulting sampling plans were tested with sequential bootstrap simulations (n = 500) using 10 independent data sets for validation. Bootstrap simulation within a wide range of densities demonstrated that actual D′ values at desired D = 0.25 averaged less than or equal to 0.25 in all cases. Even at the lowest density of leafmine (0.27 mine per leaf), the actual mean D′ was 0.24 at D = 0.25. This result shows that the sampling plan developed in this study is effective and reliable for estimating the mine densities in cucumber greenhouses.

Keywords:

• vegetable leafminer
• leafmine
• sequential sampling
• spatial distribution
• greenhouse cucumber

Acknowledgements

We are grateful for the help and technical assistance of A.A. Mohiseny, R. Amiri, R. Niknafs, K. Roshan and A. Bedrood.