Abstract
Biological control is the main purpose of intentionally introducing non‐native invertebrate species. The evolutionary changes that occur in the populations of the introduced biological control agents may determine the agent's efficiency and the environmental safety. Here, to explore the pattern and extent of potential genomic changes in the worldwide introduced predatory ladybird beetle Cryptolaemus montrouzieri, we used a reduced‐representation sequencing method to analyze the genome‐wide differentiation of the samples from two native and five introduced locations. Our analyses based on a total of 53,032 single nucleotide polymorphism loci showed that beetles from the introduced locations in Asia and Europe exhibited significant reductions in genetic diversity and high differentiation compared with the samples from the native Australian range. Each introduced population belonged to a unique genetic cluster, while the beetles from two native locations were much more similar. These genomic patterns were also detected when the dataset was pruned for genomic outlier loci (52,318 SNPs remaining), suggesting that random genetic drift was the main force shaping the genetic diversity and population structure of this biological control agent. Our results provide a genome‐wide characterization of polymorphisms in a biological control agent and reveal genomic differences that were influenced by the introduction history. These differences might complicate assessments of the efficiency of biological control and the invasion potential of this species but also indicate the feasibility of selective breeding.
Highlights
Beneficial organisms, especially invertebrate species, are used in biological control to suppress populations of pests
Similar to other biological introductions or in‐ vasions, unexpected evolutionary changes can occur in populations of biological control agents, which might decrease the efficiency of pest control or increase the risk to local environments (Fauvergue, Vercken, Malausa, & Hufbauer, 2012; Guillemaud, Ciosi, Lombaert, & Estoup, 2011)
There have been more reports of unde‐ sired side effects on local biodiversity caused by introduced biolog‐ ical control agents through rapid expansion, nontarget attack, and competition, and the invasiveness of these agents is usually related to population genetic changes (e.g., Harmonia axyridis in North and South America and Europe, Roy et al, 2016 and Cactoblastis cac‐ torum, Zimmermann, Bloem, & Klein, 2004 and Coccinella septem‐ punctata, Losey et al, 2012 in North America)
Summary
Beneficial organisms, especially invertebrate species, are used in biological control to suppress populations of pests. Host range tests in a laboratory population revealed nontarget attack abilities (Maes, Grégoire, & De Clercq, 2014) These potential risks, including range expansion and nontar‐ get attack by ladybird populations, might result from evolutionary changes that occurred during and after their introduction. Improvements in ‐generation sequencing (NGS) and bioin‐ formatic tools have spurred the development of genome‐wide ge‐ netic markers for studying the ecology and evolution of nonmodel organisms (Davey et al, 2011) This genomic methodology has been applied for the detection of genetic variation in field and mass‐reared populations of biological control agents and to elucidate the genetic basis of target traits (Lommen, Jong, & Pannebakker, 2017; van de Zande et al, 2014). The contri‐ butions of these genomic findings to biological control applications are discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
