Population Genetic Differences Between Two Cucurbit Leaf Beetles With Contrasting Feeding Preferences

Area of Science:

• Population genetics
• Insect ecology
• Molecular biology

Background:

• Aulacophora beetles are significant pests of cucurbit crops.
• Limited research exists on the population genetics of Aulacophora species.
• Understanding genetic diversity is crucial for pest management strategies.

Purpose of the Study:

• To investigate the population genetic structure of two Aulacophora beetle species, Aulacophora indica and Aulacophora lewisii.
• To compare genetic diversity and differentiation between a polyphagous and an oligophagous species.
• To explore the influence of dietary breadth on population genetic patterns.

Main Methods:

• Mitogenome sequencing of 211 individuals (102 A. indica, 109 A. lewisii).
• Analysis of genetic diversity, genetic differentiation (FST), and gene flow (Nm).
• Testing for isolation by distance (IBD) and neutrality.

Main Results:

• Aulacophora indica exhibited higher genetic diversity and gene flow compared to Aulacophora lewisii.
• A. indica populations showed low genetic differentiation and no isolation by distance.
• A. lewisii populations displayed higher genetic differentiation and significant isolation by distance.
• Neutrality tests indicated potential population expansion or positive selection in both species.

Conclusions:

• Dietary breadth is a key factor shaping population genetic characteristics in Aulacophora beetles.
• Human-mediated agriculture may influence the genetic diversity and structure of these pest populations.
• Findings provide insights into the evolutionary dynamics of cucurbit pests.