One species, two lives: cryptic population structure and life-history divergence in a vineyard spittlebug (Aphrophora sp.), a candidate vector for Pierce's disease
Whole genome analysis of spittlebug populations, an Aphrophora species (Hemiptera: Aphrophoridae) known to spread Pierce's disease, from various vineyards in Napa and Sonoma Counties demonstrates that these insects are conspecific with Aphrophora permutata found in quasi-natural populations. The genomes analyzed fall in three autosomal clusters with two sympatric populations (based on admixture)…
An in-depth genome analysis of a vineyard spittlebug species, Aphrophora sp., known to transmit Pierce's disease, has unveiled an intriguing cryptic population structure. The study, focused on insects from vineyards in Napa and Sonoma Counties, reveals that these insects are genetically identical to Aphrophora permutata found in nearby quasi-natural habitats.
The genetic data suggest three distinct autosomal clusters, with two sympatric populations that diverged roughly 40,000-90,000 years ago. Additionally, three separate mitochondrial clusters were identified, showcasing a complex genetic landscape.
Despite the genetic similarities between Napa and Sonoma County vineyard populations, the two regions show minimal differentiation. However, a striking difference in life histories emerges between these populations. Napa County vineyard insects lay eggs on understory herbs, while Sonoma County spittlebugs prefer pines. Adult migration patterns also differ, with Napa County insects showing seasonal out-migration and return, while Sonoma County adults simply move from the understory to the pine canopy.
The mitochondrial gene COI analysis further complicates the picture, indicating that Aphrophora permutata, Aphrophora fulva, Aphrophora maculosa, and even Aphrophora gelida are intermingled in the same mitochondrial group. Moreover, all three autosomal genetic clusters display evidence of selection for insecticide resistance.
Interestingly, the study also found the presence of endosymbionts Wolbachia and Rickettsia in a significant portion of the specimens, but neither of these bacteria appears to impact population structure. The findings of this genome analysis shed new light on the life history divergence between geographically close, genetically identical spittlebug populations connected by gene flow, a discovery that could have significant implications for managing vineyard populations to combat Pierce's disease.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
