Effect of Lithium Chloride on Fluctuating Asymmetry of Sternopleural Bristles in <i>Drosophila melanogaster</i> (Meigen)

The sternopleural bristle number (SBN) and sternopleural index (SI) are key traits in the taxonomy, genetics, and evolutionary research of Drosophila. This study is the first to apply SI in Fluctuating Asymmetry (FA) analysis, comparing it with SBN in the fruit fly, Drosophila melanogaster Meigen, exposed to 15, 45, and 75 mM Lithium Chloride (LiCl). FA increased significantly at 45 and 75 mM for both traits in both sexes, while 15 mM LiCl led to decreased FA in SI and increased FA in SBN (females only). Trait sizes showed no significant variation. FA comparison revealed that SI to be more robust than SBN, indicating its suitability for assessing developmental instability.