The role of black nightshade in population development of tomato russet mite (Aculops lycopersici)

The tomato russet mite (TRM), Aculops lycopersici (Tyron), is a significant pest of tomato ( Solanum lycopersicum ), with a reported ability to infest various solanaceous plants and some species outside this family. This study investigated the role of black nightshade ( Solanum nigr um), a globally widespread weed, as an alternative host for TRM and its implications for pest dynamics. The development time, survival rate, and reproductive parameters of TRM were compared between tomato and black nightshade. While TRM developed more rapidly and exhibited higher survival rates on tomato, black nightshade supported higher fecundity and a greater proportion of female offspring. These findings suggest that black nightshade can act as a viable host of TRM. Further experiments evaluated the adaptability of TRM populations to switch between tomato and black nightshade. No significant fitness costs were observed when populations were transferred between these hosts, indicating high adaptability. Additionally, we assessed the colonization potential of TRM on hosts in three different plant families, including pepper, field bindweed, petunia, tobacco, and white goosefoot. Among these, only black nightshade and field bindweed supported population growth rates comparable to tomato, while white goosefoot proved unsuitable for long-term population development. The results highlight the importance of black nightshade as a reservoir host for TRM, potentially serving as a "green bridge" that facilitates pest survival during tomato crop absences. These findings highlight the need for TRM management strategies to include effective weed control to disrupt the pest's lifecycle and reduce its economic impact on tomato cultivation.