Genome‐wide markers reveal temporal instability of local population genetic structure in the cotton fleahopper, Pseudatomoscelis seriatus (Hemiptera: Miridae)

Abstract

BACKGROUND The cotton fleahopper, Pseudatomoscelis seriatus (Reuter) (Hemiptera: Miridae), is a pest of upland cotton, Gossypium hirsutum L. (Malvales: Malvaceae), that attacks pre‐floral buds (squares), leading to abscission and yield losses. In the Brazos Valley cotton production area of Texas (USA), P. seriatus exhibits a seasonal pattern of host use. In spring, eggs hatch from stems of the overwintering host, woolly croton, Croton capitatus Michx. (Malpighiales: Euphorbiaceae). During the growing season, individuals feed on a variety of host plants, including cotton. Adults return to woolly croton at season end to oviposit. We investigated if genetic differentiation exists between populations infesting cotton and those infesting alternative hosts, and whether woolly croton serves as a year‐end site of admixture that could be suitable as a natural refuge for the purposes of insect resistance management. We combined high‐throughput DNA sequencing with fine‐scale spatio‐temporal sampling to test (i) whether a population genomic approach would recover patterns of genetic variation consistent with earlier studies and (ii) if local genetic population structure was robust to seasonal changes in local habitat over time. RESULTS We found high gene flow among populations of P. seriatus collected from different host plants in the Brazos Valley. We also identified temporal instability of the local population genetic structure, including the near complete loss of a genotypic group that had been previously abundant. CONCLUSION We support the status of woolly croton as a natural refuge that promotes year‐end gene flow between genotypes infesting cotton and those infesting alternative hosts. © 2019 Society of Chemical Industry

Population genomics and phylogeography of the boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae), in the United States, northern Mexico, and Argentina

“…Studies of economically or ecologically important fish species have long monitored changes in allele frequencies over time (Garant et al, 2000 ; Glover et al, 2012 ; Karlsson & Mork, 2005 ; Skaala et al, 2006 ), and the phenomenon has not been ignored in entomological research. Local genetic turnovers similar to the one observed in this study have been previously documented on comparable time scales in boll weevil populations in parts of Texas and Mexico using microsatellites (Choi et al, 2011 ), as well as in other insect pest species (Dinsdale et al, 2012 ; Lainhart et al, 2015 ; Raszick et al, 2020 ). Temporal instability, regardless of whether it is due to a natural process or due to management, must be considered for long‐term effectiveness of area‐wide management.…”

“…More broadly and perhaps most critically, managers must recognize the reality of the temporal instability of pest population genetic structure (Choi et al, 2011 ; Dinsdale et al, 2012 ; Lainhart et al, 2015 ; Raszick et al, 2020 ). In this study, we discovered a case of population replacement or turnover in the RGV‐Tex sampling locality from 2014 to 2016 (Figures 2 and 3 ).…”

Population Genomics of the Neotropical Brown Stink Bug, Euschistus heros: The Most Important Emerging Insect Pest to Soybean in Brazil

“…The recombination of genes from northern populations that are usually associated with common bean crops and native plants with southern populations that are strongly linked with soybean crop can be proposed as a hypothesis to explain E. heros host expansion in the Cerrado. To test this hypothesis, one has to investigate behavioral and functional differences using individuals collected in different crops in a more systematized design to reduce confounding factors (Raszick et al, 2019).…”

Unraveling the hierarchical genetic structure of tea green leafhopper, Matsumurasca onukii, in East Asia based on SSRs and SNPs

“…However, detecting subtle genetic differentiation remains a major challenge because many species, particularly r‐strategists, have large effective population sizes and high gene flow due to long‐distance dispersal or human‐mediated movement on crop plants (Matsumoto et al, 2013 ; Mun et al, 1999 ; Shi et al, 2012 ). In addition to exhibiting subtle levels of genetic differentiation, such populations may display diverse patterns of genetic structure, including classical patterns of isolation by vicariance, host, regional clustering, origin, and dispersion (Du et al, 2020 ; Goodman et al, 2019 ), as well as complex patterns that lack clear spatial structuring or that may be influenced by anthropogenic factors and habitat (Jiang et al, 2020 ; Kareem et al, 2018 ; Raszick et al, 2019 ). Identifying subtle complex genetic patterns remains a critical objective for developing effective control measures because some pest management strategies require detailed knowledge of genetic diversity and genetic structure determination that can underpin downstream efforts to measure contemporary and historical migration, delineate groups within populations, and infer evolutionary history (Jiang et al, 2020 ; Raszick et al, 2019 ).…”