Population genetic structure of the maize weevil, Sitophilus zeamais, in southern Mexico

Abstract

The maize weevil, Sitophilus zeamais, is a ubiquitous pest of maize and other cereal crops worldwide and remains a threat to food security in subsistence communities. Few population genetic studies have been conducted on the maize weevil, but those that exist have shown that there is very little genetic differentiation between geographically dispersed populations and that it is likely the species has experienced a recent range expansion within the last few hundred years. While the previous studies found little genetic structure, they relied primarily on mitochondrial and nuclear microsatellite markers for their analyses. It is possible that more fine-scaled population genetic structure exists due to local adaptation, the biological limits of natural species dispersal, and the isolated nature of subsistence farming communities. In contrast to previous studies, here, we utilized genome-wide single nucleotide polymorphism data to evaluate the genetic population structure of the maize weevil from the southern and coastal Mexican states of Oaxaca and Chiapas. We employed strict SNP filtering to manage large next generation sequencing lane effects and this study is the first to find fine-scale genetic population structure in the maize weevil. Here, we show that although there continues to be gene flow between populations of maize weevil, that fine-scale genetic structure exists. It is possible that this structure is shaped by local adaptation of the insects, the movement and trade of maize by humans in the region, geographic barriers to gene flow, or a combination of these factors.

Sublethal Effects of Chlorantraniliprole on the Mobility Patterns of Sitophilus spp.: Implications for Pest Management

“…It is therefore concluded that there is no specific trend in the response, as it seems that once these beetles were exposed to the active compound, they became more active in terms of walking, climbing, and decreasing stop durations. These findings suggest that these two sister species [ 64 ] react variably in contact with the same insecticide at sublethal concentrations. They also shed light on important negative effects of chlorantraniliprole, especially in lower concentrations, that can affect the motor activity and flying capacity of S. oryzae and eventually their population ecology.…”

Development of the first high-density linkage map in the maize weevil, Sitophilus zeamais

“…It is likely that if these techniques succeed in the field, then they will also be considered for development in other pest species. S. zeamais may be a targeted species because of its widespread geographic distribution and the threat to food security that it poses to subsistence farmers in developing nations ( Corrêa et al, 2017 ; García-Lara, García-Jaimes & Bergvinson, 2019 ; Baltzegar et al, 2023 ). However, for genetic-based technologies to be a feasible option for controlling S. zeamais , more species-specific genetic information and tools need to exist.…”