Distribution patterns and potential suitable habitat prediction of Ceracris kiangsu (Orthoptera: Arcypteridae) under climate change- a case study of China and Southeast Asia.

Ceracris kiangsu (Orthoptera: Arcypteridae), is greatly affected by climatic factors and exhibits strong adaptability, posing a serious threat to the ecological environment. Therefore, predicting its potential suitable habitat distribution provides a proactive theoretical basis for pest control. This study using the Biomod2 package of R simulated and predicted the current and future potential distribution, area changes, changes in the center points of suitable habitats, and niche shifts of C. kiangsu under two different greenhouse gas emission scenarios, SSP1-26 and SSP5-85. The results show that: (1) Currently, the high suitability areas for C. kiangsu are mainly distributed in Yunnan, Jiangxi, Hunan provinces in southern China and phongsaly province in northern Laos. In the future, the center of the suitable habitat distribution pattern of C. kiangsu will remain unchanged, primarily expanding outward from medium and high suitability areas. Additionally, significant suitable habitats for C. kiangsu were discovered in Southeast Asian countries without previous pest records. (2) Compared to the present, the overall suitable habitat area for C. kiangsu is expected to expand, particularly under the SSP5-85 climate change scenario. (3) In the SSP1-26 and SSP5-85 climate scenarios, the geometric center of the suitable habitat generally shows a trend of gradually shifting northeast. (4) Under different climate scenarios, the suitable habitat of C. kiangsu has highly overlapping, indicating that the suitable habitat of C. kiangsu in the invaded areas is broader than in its native regions. In conclusion, the research findings represent a breakthrough in identifying the potential distribution areas of C. kiangsu, which is of great practical significance for the monitoring and control of C. kiangsu pest infestation in China and Southeast Asian countries.

Identification and Expression Profile Analysis of Chemosensory Genes From the Antennal Transcriptome of Bamboo Locust (Ceracris kiangsu).

Studies of chemosensory genes are key to a better understanding of intra- and interspecific communications between insects and their environment and provide opportunities for developing environmentally friendly pesticides to target pest species. The bamboo locust Ceracris kiangsu Tsai (Orthoptera: Acrididae) is one of the most important bamboo leaf-eating insects in southern China. However, the genes underlying olfactory sensation are lacking in the bamboo locust. In this study, the transcriptomes of male and female C. kiangsu antennae were sequenced and analyzed. A total of 125 chemosensory genes, including 91 odorant receptors (ORs), 13 ionotropic receptors (IRs), 13 odorant-binding proteins (OBPs), six chemosensory proteins (CSPs), and two sensory neuron membrane proteins, were identified based on sequence alignment and phylogenetic analyses. The expression patterns of all candidate genes on the antennae of males and females, maxillary palps, tarsi, wings, and thoraxes-abdomens were confirmed by real-time quantitative PCR. The analyses demonstrated that most genes are highly expressed in the antennae, and 35 ORs, 7 IRs, 10 OBPs, and 1 CSP exhibit significantly male-biased expression patterns, indicating their potential functions in mating behavior and the recognition of female sex pheromones. In addition to the antennal-predominant genes, some were abundant in the maxillary palps and some in the non-olfactory tissues, suggesting their different functions in the olfactory system of C. kiangsu. Our research offers an extensive resource for investigating the chemoreception mechanism of C. kiangsu. Further studies of olfactory function will provide comprehensive methods and original strategies for integrated pest management.

The transcriptome analysis of the bamboo grasshopper provides insights into hypothermic stress acclimation.

The bamboo grasshopper, Ceracris kiangsu Tsai, is a pest of bamboos and widely distributed in China from high temperature plains to low temperature plateaus. In this study, high-throughput sequencing was used to analyze the transcriptome of C. kiangsu. Approximately 129,314,084 reads were generated using an Illumina sequencing. De novo assembly yielded 39,013 unigenes with an average length of 987 bp. Based on sequence similarity searches with known proteins, a total of 19,769 (50.67%) unigenes were identified. Of these annotated unigenes, 2114 and 11,412 unigenes were assigned to clusters of orthologous groups and gene ontology, respectively. Furthermore, 2128 simple sequence repeats (SSRs) were identified in the unigenes Differences were observed in gene expression after hypothermic stress, with the most up-regulated genes including heat shock protein genes (Hsps) and genes involved in ATP-binding. The down-regulation of genes involved in the catalytic activity of metabolic mechanisms was also observed. The obtained transcriptome information revealed the ability of C. kiangsu to build cold-tolerance after exposed to a mild low temperature and the transcriptional responses elicited by hypothermic stress.

A head transcriptome provides insights into odorant binding proteins of the bamboo grasshopper.

The bamboo grasshopper Ceracris kiangsu is a famous bamboo pest in China. The identification of genes involved in olfactory behavior of C. kiangsu is necessary for better understanding the molecular basis and expression profiles of behavior ecology. However, necessary genomic and transcriptomic data are lacking in the species, limiting control efficiency. The primary objective of this study was to find and describe odorant binding proteins in the head of the bamboo grasshopper. We performed the paired-end sequencing on an Illumina Hiseq2000 following the vendor's recommended protocol. Functional annotation was performed by comparison with public databases. OBP genes were first identified using BLASTN and BLASTX results from our C. kiangsu datebase, which was established from the date of transcriptome sequencing. The gene-specific primers were used to conduct RT-PCR to detect the tissue distribution of OBPs using a SYBR Premix ExTaq kit following the manufacturer's instructions with a real-time thermal cycler. We obtained more than 133 million clean reads derived from the C. Kiangsu heads using the next-generation sequencing, which were assembled into 260,822 unique sequences (average 814 bp). We have detected eight putative odorant binding protein genes (OBPs) of C. kiangsu for the first time, and analyzed the expression profiles of the OBPs in different tissues (head, antenna, mouthpart, body and leg). Our results reveal that the eight OBPs display a clear divergence, strongly indicating that they possessed diverse functions, and thus provides comprehensive sequence analysis for elucidating the molecular basis of OBPs in C. kiangsu. In addition, we find that the relative expression levels of OBP1, OBP2 and OBP8 are significantly higher in the antennae as compared to the other OBP genes, suggesting that these three OBP genes play crucial roles in the locust's odorant discrimination. In general, this is the first study to characterize the complete head transcriptome of C. kiangsu using high-throughput sequencing. The study opens a window for functional characterization of the OBPs of C. kiangsu, with potential for new or refined applications of semiochemicals for control of this notorious pest.