Invasion of sorghum in the Americas by a new sugarcane aphid (Melanaphis sacchari) superclone

PLoS One. 2018 Apr 25;13(4):e0196124. doi: 10.1371/journal.pone.0196124. eCollection 2018.

Abstract

In the United States (US), the sugarcane aphid (SCA) Melanaphis sacchari (Zehnter) (Hemiptera: Aphididae) was introduced in the 1970s, however at that time it was only considered a pest of sugarcane. In 2013, a massive outbreak of M. sacchari occured on sorghum, resulting in significant economic damage to sorghum grown in North America including the US, Mexico, and Puerto Rico. The aim of the present study was to determine if the SCA pest emergence in American sorghum resulted from the introduction of new genotypes. To this end we used microsatellite markers and COI sequencing to compare the genetic diversity of SCA populations collected in the Americas after the 2013 SCA outbreak on sorghum (during 2013-2017) to older samples collected before the pest outbreak (during 2007-2009). Our results show that the SCA outbreak in the Americas and the Caribbean observed since 2013 belong to populations exhibiting low genetic diversity and consisting of a dominant clonal lineage, MLL-F, which colonizes Sorghum spp. and sugarcane. The comparison of MLL-F specimens collected post-2013 with specimens collected in Louisiana in 2007 revealed that both populations are genetically distinct, according to COI sequencing and microsatellite data analyses. Our result suggest that MLL-F is a new invasive genotype introduced into the Americas that has spread rapidly across sorghum growing regions in the US, Mexico, Honduras and the Caribbean. The origin of this introduction is either Africa or Asia, with Asia being the most probable source.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aphids / genetics*
  • Aphids / physiology
  • Electron Transport Complex IV / genetics
  • Genetic Variation
  • Genotype
  • Insect Proteins / genetics
  • Introduced Species
  • Microsatellite Repeats*
  • North America
  • Sequence Analysis, DNA / methods*
  • Sorghum / parasitology*

Substances

  • Insect Proteins
  • Electron Transport Complex IV

Grants and funding

This work was co-funded by the European Union: Agricultural Fund for Rural Development (https://ec.europa.eu/agriculture/cap-funding_en), by the Conseil Départemental de La Réunion (http://www.cg974.fr), by the Conseil Régional de La Réunion (https://www.regionreunion.com) and by the Centre de Coopération internationale en Recherche agronomique pour le Développement (www.cirad.fr), as well as by the Southern Region IPM Center in the US award number 2012-51120- 20088 from the USDA National Institute of Food and Agriculture (https://nifa.usda.gov/grants), the United Sorghum Checkoff Program (https://www.ams.usda.gov/rules-regulations/research-promotion/sorghum), and was carried out in part on the Plant Protection Platform which is co-financed by the Groupe d'Intérêt Scientifique "Infrastructures en Biologie Santé et Agronomie" (www.ibisa.net). The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the United States Department of Agriculture or the Agricultural Research Service of any product or service to the exclusion of others that may be suitable. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.