Mitochondrial DNA and trade data support multiple origins of Helicoverpa armigera (Lepidoptera, Noctuidae) in Brazil

Abstract

The Old World bollworm Helicoverpa armigera is now established in Brazil but efforts to identify incursion origin(s) and pathway(s) have met with limited success due to the patchiness of available data. Using international agricultural/horticultural commodity trade data and mitochondrial DNA (mtDNA) cytochrome oxidase I (COI) and cytochrome b (Cyt b) gene markers, we inferred the origins and incursion pathways into Brazil. We detected 20 mtDNA haplotypes from six Brazilian states, eight of which were new to our 97 global COI-Cyt b haplotype database. Direct sequence matches indicated five Brazilian haplotypes had Asian, African, and European origins. We identified 45 parsimoniously informative sites and multiple substitutions per site within the concatenated (945 bp) nucleotide dataset, implying that probabilistic phylogenetic analysis methods are needed. High diversity and signatures of uniquely shared haplotypes with diverse localities combined with the trade data suggested multiple incursions and introduction origins in Brazil. Increasing agricultural/horticultural trade activities between the Old and New Worlds represents a significant biosecurity risk factor. Identifying pest origins will enable resistance profiling that reflects countries of origin to be included when developing a resistance management strategy, while identifying incursion pathways will improve biosecurity protocols and risk analysis at biosecurity hotspots including national ports.

Invasion origin, rapid population expansion, and the lack of genetic structure of cotton bollworm (Helicoverpa armigera) in the Americas

“…Common mtDNA haplotypes are shared among the Americas, Europe, Africa, and Asia, including the sharing of alleles associated with pyrethroid resistance (Durigan et al, ; Tay et al, ). Furthermore, H. armigera populations show weak genetic structure and high gene flow in the Old World and Australia (Anderson et al, ; Behere et al, ; Endersby, Hoffmann, McKechnie, & Weeks, ; Li et al, ; Nibouche, Bues, Toubon, & Poitout, ; Tay et al, ; Vijaykumar, Krishnareddy, Kuruvinashetti, & Patil, ; Weeks et al, ).…”

“…However, they also reduce the impact of this information because there is a wide transference of alleles among geographical sites in the Old World (Anderson et al, ; Behere et al, ; Nibouche et al, ; Rasool et al, ; Stokes, Mckechnie, & Forrester, ). Finally, there is consensus that the invasion of South America by H. armigera was not originated from Oceania (Anderson et al, ; Durigan et al, ; Tay et al, ).…”

“…Recent population studies revealed a high genetic diversity of H. armigera populations in Brazil and genetic similarity among Brazilian individuals with populations originating in Europe, Africa, and Asia (Anderson, Tay, McGaughran, Gordon, & Walsh, ; Leite, Alves‐Pereira, Corrêa, Zucchi, & Omoto, ; Mastrangelo et al, ; Tay et al, ). The high genetic diversity of H. armigera increases doubts surrounding an invasion process and population dynamics of H. armigera in Brazil, since high genetic diversity is not expected in invasive insects due to the founder effect of invasion processes.…”

Phylogeography of Diaphorina citri (Hemiptera: Liviidae) and its primary endosymbiont, ‘Candidatus Carsonella ruddii’: an evolutionary approach to host–endosymbiont interaction

“…Because of their relatively rapid rates of molecular evolution compared with nuclear loci, mitochondrial loci are often used to evaluate geographic variation in introduced species and to trace their movement and origins . The biodiversity of D. citri has been assessed in several regions using mitochondrial COI markers .…”

Chromosomal deletions mediated by CRISPR/Cas9 in Helicoverpa armigera

“…The cotton bollworm, Helicoverpa armigera , one of the most serious pests in China (Wu & Guo, ), has recently become one of the most economically important pests worldwide (Tay et al ., ). Insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are widely used in sprays and transgenic plants to control this pest (Sanahuja et al ., ).…”