Source population determination for boll weevil re-infestation Events in Texas

Area of Science:

• Agricultural Entomology
• Population Genetics
• Genomics

Background:

• The boll weevil (Anthonomus grandis grandis) is a major cotton pest in the Americas.
• Endemic populations in the Lower Rio Grande Valley (LRGV) threaten U.S. cotton production.
• Identifying the geographic origin of boll weevils in eradicated zones aids control efforts.

Purpose of the Study:

• To determine the geographic origin of a 2018 boll weevil outbreak in Kingsville, Texas.
• To assess the utility of genomic and population genetic methods for agricultural pest management.

Main Methods:

• Utilized whole-genome sequencing to analyze population ancestry and relatedness.
• Compared genetic signatures with historical outbreaks and LRGV populations.
• Validated relatedness metrics using the model insect Tribolium castaneum.

Main Results:

• The 2018 Kingsville outbreak originated from an independent introduction from the LRGV.
• Samples from the outbreak showed close relatedness, suggesting recent reproduction.
• Methods demonstrated effectiveness for non-model insect population studies.

Conclusions:

• Genomic and population genetic approaches are valuable for tracing pest origins.
• Understanding boll weevil dispersal and reproduction aids agricultural management.
• Independent introductions from the LRGV pose an ongoing threat to eradicated zones.