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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Insect Control and Cotton Disease Research » Research » Publications at this Location » Publication #415649
Research Project: Novel Approaches for Management of Row Crop Pests and Continued Boll Weevil Eradication

Location: Insect Control and Cotton Disease Research

Title: Pangenomics links boll weevil divergence with ancient Mesoamerican cotton cultivation

Author
item Cohen, Zachary
item Perkin, Lindsey
item RASZICK, TYLER - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center
item Sim, Sheina
item Geib, Scott
item Childers, Anna
item SWORD, GREG - Texas A&M University
item Suh, Charles

Submitted to: Molecular Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2024
Publication Date: 1/22/2025
Citation: Cohen, Z.P., Perkin, L.C., Raszick, T.J., Sim, S.B., Geib, S.M., Childers, A.K., Sword, G.A., Suh, C. P.-C. 2025. Pangenomics links boll weevil divergence with ancient Mesoamerican cotton cultivation. Molecular Ecology. Article e14054. https://doi.org/10.1111/1755-0998.14054.
DOI: https://doi.org/10.1111/1755-0998.14054

Interpretive Summary: The boll weevil is a destructive pest of commercial cotton, but has been eradicated from most of the United States with the exception of south Texas. However, programs in eradicated areas continue to operate pheromone traps to detect boll weevil re-infestations. These traps commonly capture other non-pest weevil species, including the thurberia weevil, which looks nearly identical to the boll weevil but feeds on wild non-cultivated cotton species. Non-pest weevils misidentified as boll weevils could lead to unnecessary and costly mitigation efforts. Conversely, misidentification of boll weevils could delay or preclude necessary remedial actions. We found over 40,000 genetic differences between these subspecies that include genes involved in reproduction, regulation, and metabolism. We also identified several candidate genes that may be used to develop a diagnostic tool that can be used in the field to rapidly differentiate these two subspecies.

Technical Abstract: The boll weevil, Anthonomus grandis grandis Boheman, and thurberia weevil, Anthonomus grandis thurberia Pierce (Coleoptera: Curculionidae), together comprise a species complex that ranges throughout Mexico and the southern regions of the United States. The boll weevil is a historically damaging and contemporaneously threatening pest to commercial Upland cotton, Gossypium hirsutum, whereas the thurberia weevil is regarded as an innocuous non-pest species that is mostly found on non-cultivated cotton species, e.g Thurber’s or Arizona cotton, G. thurberi, throughout its western native range. Recent independent analyses using mitochondrial COI and whole genome ddRADseq suggested the independent evolution of these lineages largely attributed to geographic isolation and not host plant preference. We furthered this investigation by employing comparative genomic, population genetic, and pangenome methodologies to identify large and small polymorphisms within this complex and described their role in demography and adaptation. We also leveraged genetic differences to identify nearly 40,000 diagnostic loci between the subspecies, find genes under selection, and model the subspecies’ shared and unique evolutionary history. Interestingly, structural variations capture a large proportion of genes at the population level and demographic reconstruction suggests a split between these subspecies that coincides with cotton cultivation in southern Texas. Observed polymorphisms are enriched for reproductive, regulatory, and metabolic genes which may be attributed to the boll weevil’s explosive expansion onto commercial cotton.