A genomic looking glass: Developing genomic tools to study Nipaecoccus viridis Newstead (Hemiptera: Pseudococcidae), an invasive mealybug pest in Florida citrus

Monday, November 11, 2024

10:42 AM – 10:54 AM MST

Location: Phoenix Convention Center, 224 B, PCC

Presenting Author(s)

TL

Tracy Liesenfelt (she/her/hers)

Graduate Student
University of Florida
Gainesville, Florida

Co-Author(s)

EP

Erin Powell

Research Scientist, Curator of Hemiptera
Florida State Collection of Arthropods
Gainesville, Florida
AM

Andrew J. Mongue

University of Florida
Gainesville, Florida

Advancements within genomic technology have opened the door to study non-model insects, including important agricultural pests. One such insect is the Lebbeck mealybug, Nipaecoccus viridis (Newstead), an invasive hemipteran pest that was originally native to Asia but has since spread to at least 60 different countries. More recently, N. viridis has become a pest of concern within Florida’s commercial citrus. While initially first found in a natural area in 2009, it was not until 2019 that the mealybug was found in commercial citrus groves and since spread to numerous counties within the state. With the invasion still in the early phase, this allows us to study the invasion dynamics and characterize the genetic variation in individuals collected across Florida. To accomplish this goal, we generated a chromosome level de novo genome assembly using PacBio long reads in combination with Illumina Hi-C scaffolding. We have assembled 91.2% of the 289 Mb assembly to one of five chromosomal sequences. We then conducted an analysis of population genetics using Illumina short-read sequencing of 20 samples from 12 counties aligned to the reference genome to examine the genetic variation across samples. We find evidence of two main distinct populations of Nipaecoccus viridis across Florida, not isolated by distance or host plants but rather differences in agricultural practice. This suggests that there may have been multiple introductions into Florida, likely through human-mediated dispersal. Our results give insight into the global invasive success of N. viridis and provide key molecular resources for monitoring this citrus pest.