Evaluation of a low-cost staining method for improved visualization of sweet potato whitefly (Bemisia tabaci) eggs on multiple crop plant species

The sweet potato whitefly (Bemisia tabaci) is a damaging insect pest that feeds on hundreds of crop plants. Oviposition rate is a useful metric to screen plants for whitefly resistance. Whitefly eggs are small and translucent, and can therefore be hard to count on the leaves of some crops. In this research, we tested a selective egg staining process on five crop species to determine if egg staining can improve the visualization and quantification of whitefly eggs. By comparing the egg counts before and after staining using two-sample Wilcoxon signed-rank tests (a non-parametric test for paired analyses). Two individuals counted the eggs, and for both these counters we found a significant increase in the number of visible eggs after staining on melon, tomato, and cowpea. This method could be applied to improve phenotyping for whitefly resistance in plant breeding applications.