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Background: The tomato leafminer, Phthorimaea absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a destructive invasive pest that originated in South America and has spread within China since 2017. A rapid method for on-site identification of P. absoluta is urgently needed for interception of this pest across China., Results: We developed a loop-mediated isothermal amplification (LAMP) technique to differentiate P. absoluta from Liriomyza sativae, Chromatomyia horticola, and Phthorimaea operculella using extracted genomic DNA, which was then refined to create an on-site LAMP diagnostic method that can be performed under field conditions without the need for laboratory equipment., Conclusion: In the present research, we developed an on-site diagnostic method for rapid differentiation of P. absoluta from other insects with similar morphology or damage characteristics in China. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

In Liaoning Province, China, tomato yellow leaf curl virus (TYLCV) was first detected in 2009 and in only four counties. To quantify the spread of TYLCV and to identify potential factors influencing its spread in Liaoning Province, we assayed for TYLCV within 1,055 whiteflies (Bemisia tabaci (Gennadius) complex) from 74 populations and 29 counties in 2011. The B. tabaci species of these individuals was determined based on molecular markers. TYLCV was found in 13 counties (Donggang, Liaoyang, Kazuo, Lingyuan, Heishan, Liaozhong, Kaiyuan, Taian, Dawa, Dashiqiao, Beizhen, Linghai, and Xingcheng) and was most frequently detected in the central plain. In addition, the percentage of whiteflies with TYLCV was significantly higher in B. tabaci Q than in B. tabaci B but was unrelated to the hosts (pepper, eggplant, tomato, cucumber, and kidney bean) on which the whiteflies had been collected. These results demonstrate that TYLCV has spread rapidly in Liaoning Province since its first detection and suggest that its spread is more closely associated with the introduction of B. tabaci Q than with the species of host plant. These findings also indicate that controls are now needed to reduce the further spread of TYLCV and that these controls should include the management of B. tabaci Q populations.

Background: Even though introductions of exotic species provide ready-made experiments of rapid evolution, few studies have examined the genetic structure of an exotic species shortly after its initial introduction and subsequent spread. To determine the genetic structure of its populations during the initial introduction, we investigated the invasive sweet potato whitefly (Bemisia tabaci Q, commonly known as B. tabaci biotype Q) in China, which was introduced in approximately 2003. A total of 619 B. tabaci Q individuals in 20 provinces throughout China were collected and analyzed using five microsatellite loci., Results: The introduced populations of B. tabaci Q in China represent eight genetic clusters with different geographic distributions. The populations in Yunnan Province, where B. tabaci Q was first detected, are genetically different from the other populations in China., Conclusion: The introduced populations of B. tabaci Q in China have high spatial genetic heterogeneity. Additional research is required to determine whether the heterogeneity results from multiple introductions, rapid evolution following one or few introductions, or some combination of multiple introductions and rapid evolution. The heterogeneity, however, is inconsistent with a single introduction at Yunnan Province, where B. tabaci Q was first detected, followed by spread.

Background: MicroRNAs (miRNAs) are small, conserved, non-coding RNAs that post-transcriptionally regulate gene expression. Bemisia tabaci (Gennadius) B and Q are two invasive and dominant whiteflies, and B. tabaci Q has been displacing B in China. Differences in biological traits (fecundity, host range, resistance to insecticides, etc.) as affected by miRNAs might be involved in the displacement. In this study, we performed high-throughput sequencing to identify miRNAs in B. tabaci B and Q., Results: We identified 170 conserved miRNAs and 15 novel candidates, and found significant differences in the expression of miRNAs between B. tabaci B and Q., Conclusion: Expression levels of miRNAs differ in B. tabaci B vs. Q. Additional research is needed to determine whether these differences are related to differences in the biology of B. tabaci B and Q, and whether these differences help explain why B. tabaci Q is displacing B in China.