Significant plant pests such as fruit flies that travel with fresh produce between countries as eggs or larvae pose a great economic threat to the agriculture and fruit industry worldwide. Time‐limited and expensive quarantine decisions require accurate identification of such pests. Immature stages are often impossible to identify, making them a serious concern for biosecurity agencies. Use of COI barcoding PCR, often the only molecular identification resource, is time‐consuming. We assess the suitability of the COI barcoding region for real‐time PCR assays to identify four pest fruit fly species (Family: Tephritidae), in a diagnostic framework. These species, namely Mediterranean fruit fly (Ceratitis capitata), Queensland fruit fly (Bactrocera tryoni), African invader fly (Bactrocera invadens) and Island fly (Dirioxa pornia) each provide a different set of genetic species delimitation problems. We discuss the benefits and limitations of using a single‐gene TaqMan™ real‐time approach for such species. Our results indicate that COI‐based TaqMan™ real‐time PCR assays, in particular for genetically distinct species, provide an accurate, sensitive and rapid diagnostic tool.

Spider mites of the genus Tetranychus are difficult to identify due to their limited diagnostic characters. Many of them are morphologically similar and males are needed for species-level identification. Tetranychus urticae is a common interception and non-regulated pest at New Zealand’s borders, however, most of the intercepted specimens are females and the identification was left at Tetranychus sp. Consequently, the shipments need to be fumigated. DNA sequencing and PCR-restriction fragment length polymorphism (PCR-RFLP) protocols could be used to facilitate the accurate identification. However, in the context of border security practiced in New Zealand, insect identifications are required to be provided within four hours of receiving the samples; thus, those molecular methods are not sufficient to meet this requirement. Therefore, a real-time PCR TaqMan assay was developed for identification of T. urticae by amplification of a 142 bp Internal Transcribed Spacer (ITS) 1 sequence. The developed assay is rapid, detects all life stages of T. urticae within three hours, and does not react with closely related species. Plasmid DNA containing ITS1 sequence of T. uritcae was serially diluted and used as standards in the real-time PCR assay. The quantification cycle (Cq) value of the assay depicted a strong linear relationship with T. urticae DNA content, with a regression coefficient of 0.99 and efficiency of 98%. The detection limit was estimated to be ten copies of the T. urticae target region. The assay was validated against a range of T. urticae specimens from various countries and hosts in a blind panel test. Therefore the application of the assay at New Zealand will reduce the unnecessary fumigation and be beneficial to both the importers and exporters. It is expected that the implementation of this real-time PCR assay would have wide applications in diagnostic and research agencies worldwide.

Background In the past decade, the brown marmorated stink bug (BMSB), Halyomorpha halys (Hemiptera: Pentatomidae) has caused extensive damage to global agriculture. As a high-risk pest for many countries, including New Zealand, it is important to explore its genetic diversity to enhance our knowledge and devise management strategies for BMSB populations. In this study, two mitochondrial genes, Cytochrome c oxidase I (COI) and Cytochrome c oxidase II (COII) were used to explore the genetic diversity among 463 BMSB individuals collected from 12 countries. Result In total, 51 COI and 29 COII haplotypes of BMSB were found, which formed 59 combined haplotypes (5 reported and 54 novel). Of these, H1h1 was the predominant haplotype. The haplotype diversity (Hd) and nucleotide diversity (π) were high while the neutrality (Fu’s Fs) values were negative for the BMSB populations in the native countries, China, and Japan. For the BMSB populations from the invaded countries, the Fu’s Fs values were negative for populations from Chile, Georgia, Hungary, Italy, Romania, Turkey, and USA, indicating that those populations are under demographic expansion. In comparison, the Fu’s Fs values were positive for the populations from Austria, Serbia, and Slovenia, revealing a potential population bottleneck. Analysis of molecular variance (AMOVA) suggested that significant genetic difference exists among the BMSB populations from China, Japan, and the invasive countries. Conclusion This study revealed that the haplotype diversity of the BMSB populations was high in those two studied countries where BMSB is native to (China and Japan) but low in those countries which have been invaded by the species. The analysis indicated that multiple invasions of BMSB occurred in Europe and the USA. The study also revealed three ancestral lines and most of the novel haplotypes were evolved from them. Moreover, we observed two genetic clusters in the invasive populations that are formed during different invasion events. Our study provided a comprehensive overview on the global haplotypes distribution thus expanding the existing knowledge on BMSB genetic diversity that potentially could play an important role in formulating feasible pest management strategies.

Background Brown marmorated stink bug (BMSB), Halyomorpha halys (Hemiptera: Pentatomidae) is native to East Asia but has invaded many countries in the world. BMSB is a polyphagous insect pest and causes significant economic losses to agriculture worldwide. Knowledge on the genetic diversity among BMSB populations is scarce but is essential to understand the patterns of colonization and invasion history of local populations. Efforts have been made to assess the genetic diversity of BMSB using partial mitochondrial DNA sequences but genetic divergence on mitochondria is not high enough to precisely accurately identify and distinguish various BMSB populations. Therefore, in this study, we applied a ddRAD (double digest restriction-site associated DNA) sequencing approach to ascertain the genetic diversity of BMSB populations collected from 12 countries (2 native and 10 invaded) across four continents with the ultimate aim to trace the origin of BMSBs intercepted during border inspections and post-border surveillance. Result A total of 1775 high confidence single nucleotide polymorphisms (SNPs) were identified from ddRAD sequencing data collected from 389 adult BMSB individuals. Principal component analysis (PCA) of the identified SNPs indicated the existence of two main distinct genetic clusters representing individuals sampled from regions where BMSB is native to, China and Japan, respectively, and one broad cluster comprised individuals sampled from countries which have been invaded by BMSB. The population genetic structure analysis further discriminated the genetic diversity among the BMSB populations at a higher resolution and distinguished them into five potential genetic clusters. Conclusion The study revealed hidden genetic diversity among the studied BMSB populations across the continents. The BMSB populations from Japan were genetically distant from the other studied populations. Similarly, the BMSB populations from China were also genetically differentiated from the Japanese and other populations. Further genetic structure analysis revealed the presence of at least three genetic clusters of BMSB in the invaded countries, possibly originating via multiple invasions. Furthermore, this study has produced novel set of SNP markers to enhance the knowledge of genetic diversity among BMSB populations and demonstrates the potential to trace the origin of BMSB individuals for future invasion events.

This datasheet on Solenopsis invicta covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.