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The Sakhalin pine sawyer Monochamus saltuarius (Gebler) (Coleoptera: Cerambycidae) is a new vector of pine wood nematode in China, which has caused huge economic losses in the forestry industry. The mating process of M. saltuarius has been described in detail. However, mate choice and sexual selection in this species are not fully understood. In this study, we quantitatively evaluated the characteristics associated with contact between the sexes in mating and inferred the sex-specific characteristics under selection. We detected positive correlations between the morphological characteristics of females and males. Most female traits and all male traits differed significantly between mated and unmated individuals. The results of this study provide evidence for the selection of the mating preferences in M. saltuarius. [ABSTRACT FROM AUTHOR]

Monochamus saltuarius (Coleoptera: Cerambycidae) is a native pest common in pine forests of Northeast China and an effective dispersal vector for the invasive species Bursaphelenchus xylophilus, a cause of pine wilt disease. However, the lack of a rapid and accurate method for the identification of M. saltuarius limits surveillance and control efforts. In this study, we developed species‐specific primers, MsF/MsR, targeting cytochrome C oxidase subunit I (COI) for the rapid PCR‐based identification of M. saltuarius. Analyses of M. saltuarius sampled at different developmental stages and from five geographical origins supported the high specificity of the assay. Furthermore, M. saltuarius ‐specific COI primers amplified M. saltuarius DNA only with a lower limit of detection of 20 pg/μl, demonstrating the high sensitivity. The newly developed PCR‐based assay provides a rapid, simple, accurate and reproducible method for the determination of M. saltuarius regardless of condition, life stage and populations. The detection process could generally be completed within 2–3 hr and is therefore feasible for quarantine surveillance. The proposed approach may improve the early detection and continuous monitoring of M. saltuarius populations and thereby facilitate the control of B. xylophilus spread. [ABSTRACT FROM AUTHOR]

Background: In many insect species, the larvae/nymphs are unable to disperse far from the oviposition site selected by adults. The Sakhalin pine sawyer Monochamus saltuarius (Gebler) is the newly discovered insect vector of the pine wood nematode (Bursaphelenchus xylophilus) in China. Adult M. saltuarius prefers to oviposit on the host plant Pinus koraiensis, rather than P. tabuliformis. However, the genetic basis of adaptation of the larvae of M. saltuarius with weaken dispersal ability to host environments selected by the adult is not well understood. Results: In this study, the free amino and fatty acid composition and content of the host plants of M. saltuarius larvae, i.e., P. koraiensis and P. tabuliformis were investigated. Compared with P. koraiensis, P. tabuliformis had a substantially higher content of various free amino acids, while the opposite trend was detected for fatty acid content. The transcriptional profiles of larval populations feeding on P. koraiensis and P. tabuliformis were compared using PacBio Sequel II sequencing combined with Illumina sequencing. The results showed that genes relating to digestion, fatty acid synthesis, detoxification, oxidation-reduction, and stress response, as well as nutrients and energy sensing ability, were differentially expressed, possibly reflecting adaptive changes of M. saltuarius in response to different host diets. Additionally, genes coding for cuticle structure were differentially expressed, indicating that cuticle may be a potential target for plant defense. Differential regulation of genes related to the antibacterial and immune response were also observed, suggesting that larvae of M. saltuarius may have evolved adaptations to cope with bacterial challenges in their host environments. Conclusions: The present study provides comprehensive transcriptome resource of M. saltuarius relating to host plant adaptation. Results from this study help to illustrate the fundamental relationship between transcriptional plasticity and adaptation mechanisms of insect herbivores to host plants. [ABSTRACT FROM AUTHOR]