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Cinnamomum camphora(L.) J. Presl. (Laurales: Lauraceae) is widely cultivated as an important landscape tree species in many urban areas in South China, especially in Shanghai City.Pagiophloeus tsushimanusMorimoto has become a destructive insect pest ofC.camphoraplantations in Shanghai, but the biological and ecological traits of this pest remain largely unknown. In this study, we investigated the damage and life history and determined the larval instar ofP.tsushimanus. The results indicated thatP.tsushimanusis a monophagous weevil pest, andC.camphorais the unique host tree species.C.camphoraplantations in all administrative districts of Shanghai have been seriously damaged byP.tsushimanus. Adults often aggregate for feeding on the tender bark of twigs and occasionally on newly emerged buds. After experiencing damage, the twigs shrink and crack and the buds will shrink. Adults tend to repeatedly mate and oviposit, and all females lay single eggs at a time. Eggs will be covered with a mixture of secretions and wood chips by female adults. Larvae (1st–2nd instar) feed on the phloem, while 3rd–5th instar can bore into the phloem and the cambium. Massive tunnels, including three shapes (inverted “L”, inverted “T”, and inverted “Z”), were observed in the trunk of each tree, and resulted in swelling of the outer bark.P.tsushimanushas one life cycle per year in Shanghai. Both adults and larvae (3rd–5th instar) overwinter from early November to early April. Adults overwinter in grooves on the underside of branches or at branch nodes, and larvae overwinter in tunnels. Five larval instars ofP.tsushimanuswere determined according to Dyar's and Crosby's rules. The biological traits and life history ofP.tsushimanushave been identified and can provide guidance in terms of pest control and plantation management.

Pagiophloeus tsushimanus is a newly and specialist wood-boring beetle of Cinnamomum camphora in China. RT-qPCR is an accurate quantitative method to quantify target genes expression, which relies on suitable reference genes for data normalization. Reference genes must to be stably expressed under specific experimental conditions. No suitable reference genes of P. tsushimanus have been reported so far. Therefore, it is necessary to identify and evaluate suitable reference genes for the study of functional genes of this pest. In this research, the expression stability of eight candidate reference genes (RPS3, 18S rRNA, GAPDH, TBP, RPL10, UBQ, GST, and RPS27A) were systematically evaluated in P. tsushimanus by five algorithms (geNorm, BestKeeper, NormFinder, delta Cq, and RefFinder) under different developmental stages, various tissues, and insects reared on different plants, and validated by the olfactory key gene odorant binding protein 33 (PtsuOBP33). The results showed that three stable reference genes combination were necessary for quantitative analysis of target gene. RPS3, RPL10, and UBQ were the optimal reference genes combination for gene expression analysis of developmental stages, while RPL10, RPS3, and 18S rRNA were recommended for different tissues, and 18S rRNA, TBP, and RPS3 were recommended for insects reared on different plants. The results indicated that suitable reference genes should be screened out for gene expression analysis under different conditions. This paper systematically analyzed and obtained suitable reference genes in P. tsushimanus for the first time, which would contribute to the functional analysis of genes and the in-depth mining of genetic resources in it.

Pagiophloeus tsushimanus is a new, destructive, and monophagous weevil pest that thrives on Cinnamomum camphora, found in Shanghai. The functions of chemosensory genes involved in the host location and intraspecific communication of P. tsushimanus remain unknown. The male–female transcriptomes of P. tsushimanus adults were assembled using Illumina sequencing, and we focused on all chemosensory genes in transcriptomes. In general, 58,088 unigenes with a mean length of 1018.19 bp were obtained. In total, 39 odorant binding proteins (OBPs), 10 chemosensory proteins (CSPs), 22 olfactory receptors (ORs), 16 gustatory receptors (GRs), eight ionotropic receptors (IRs), and five sensory neuron membrane proteins (SNMPs) were identified. PtsuOBPs comprised four subfamilies (20 Minus-C, one Plus-C, two Dimer, and 15 Classic). Both PtsuOBPs and PtsuCSPs contained a highly conserved sequence motif of cysteine residues. PtsuORs including one olfactory receptor co-receptors (Ptsu/Orco) comprised seven predicted transmembrane domains. Phylogenetic analysis revealed that PtsuOBPs, PtsuCSPs, and PtsuORs in P. tsushimanus exhibited low homology compared to other insect species. The results of tissue- and sex-specific expression patterns indicated that PtsuOBPs and PtsuORs were highly abundant in the antennae; whereas, PtsuCSPs were not only highly abundant in antennae, but also abdominal apexes, wings, and legs. In conclusion, these results enrich the gene database of P. tsushimanus, which may serve as a basis for identifying novel targets to disrupt olfactory key genes and may provide a reverse validation method to identify attractants for formulating potential eco-friendly control strategies for this pest.

Currently, most advanced object detectors equip with deep convolutional neural network (CNN) backbones(e.g., ResNet-101) for capturing strong feature representation, but which leads to suffer heavy computational burden. Inversely, some detectors based on lightweight backbones implement real-time processing while accuracy is often not satisfactory. In this paper, we explore an approach to construct a light yet powerful detector by using efficient lightweight backbone (e.g., MobileNet) with our proposed Feature Fusion Block (FFB), composed of Feature Aggregation Block (FAB) and Dense Feature Pyramid (DFP). The extensive experiments confirmed that our proposed Feature Fusion Block Network (FFBNet) is able to improve the accuracy significantly of MobileNet-SSD as well as maintain a close processing speed. Specifically, on Pascal VOC datasets, FFBNet achieves 73.54 mAP at speed of 185 FPS and surpasses MobileNet-SSD five points. Moreover, we apply VGG16 as backbone to further indicate the effectiveness of FFB, which reaches 80.2 mAP on Pascal VOC benchmark. Code is available at https://github.com/fanbinqi/FFBNet.

Overwintering adult female Brevipalpus lewisi feed on the new lower leaf surface of M. glyptostroboides and aggregate along the mid-vein in mid-May, depositing oval reddish eggs on the petiole in four to eight clusters. The population markedly decrease during the Meiyu season (East Asian rainy season) of June and early July, but increase and disperse over the plants in late July and early August. Afterwards, the population grow quickly and reach the highest density in late September. Finally, in late November, the adult female mites overwinter in the leaf sheath of current-year and one-year-old twigs. Premlinary observations suggest B. lewisi developmental rates are strongly influenced by the environmental conditions, especially temperature and rainfall. Dry and low-rainfall make the mites most virulent, leading to the outbreak period from August to October.