【Aim】The objective of this research is to explore the effects of DOPA decarboxylase (DDC) on fecundity in the multicolored Asian beetle, Harmonia axyridis, and its regulatory mechanism. 【Methods】RNA interference (RNAi) was used to suppress the expression of DDC gene (HaDDC) in the 4th instar larvae of H. axyridis, and the cumulative number of eggs laid in 20 d was counted from the 8th day after adult emergence and the egg hatching rate of offspring was recorded on the 3rd day after egg laying. Then the ovaries of female adults of H. axyridis were dissected, the ovarian tissue morphology and the number of ovarioles of the 8-day-old adults between the treatment group (injected with dsHaDDC) and the control group (injected with dsGFP), and the development of eggs in the ovarioles of the 14- and 20-day-old adults between the treatment group and the control group were observed and recorded.【Results】After the expression of HaDDC gene of both sexes of H. axyridis was inhibited by RNAi, the cumulative number of eggs laid by adults in 20 d was 38.67±7.80, which was significantly lower than that of the control group (371.33±84.31). After the expression of HaDDC gene in female and male adults was inhibited, the cumulative numbers of eggs laid in 20 d were 135.50±28.38 and 76.00±14.00, respectively, which were significantly different from that of the control group. The egg hatching rate of offspring was 0 when the expression of HaDDC gene in both sexes was inhibited. On the 8th day after emergence of H. axyridis, the ovarian tissue morphology and the number of ovarioles in the treatment group were not significantly different from the control. On the 14th day after adult emergence, the ovaries of H. axyridis were plump, and the oocytes were developed in the bilateral ovarioles. However, compared with the control group, no mature eggs were found in the treatment group.【Conclusion】Based on the above results, we can preliminarily conclude that DDC can regulate the fecundity of H. axyridis by participating in the development process from oocyte to mature eggs.

【Aim】To explore the role of 3-hydroxy-3-methylglutaryl coenzyme A reductase gene (HMGR), a key gene of juvenile hormone (JH) biosynthesis, in the reproduction of the white-backed planthopper, Sogatella furcifera.【Methods】Based on the published genome and transcriptome data of S. furcifera, the full-length cDNA sequence of SfHMGR was obtained by RT-PCR. The expression profiles of SfHMGR in different developmental stages (1st-5th instar nymph and female adult) and different tissues (head, gut, fat body, ovaries and integument) of female adults of S. furcifera were detected by RT-qPCR. After targeted silencing of SfHMGR by RNAi technology, the ovarian development of female adults was observed, the number of eggs laid by per female adult of S. furcifera was counted, and the transcription levels of downstream genes of JH biosynthesis (SfJHAMT and SfFAMeT), JH signal transduction related genes (SfMet and SfKr-h1), and the key genes of ovarian development (SfVg and SfVgR) were determined by RT-qPCR. 【Results】The full-length cDNA sequence of SfHMGR (GenBank accession number: MW883397) of S. furcifera was cloned, with an open reading frame of 2 724 bp in length, encoding 907 amino acids. The predicted molecular weight of the protein is 98.96 kD, and the theoretical isoelectric point is 6.15. Sequence analysis showed that SfHMGR contains typical HMG-CoA reductase conserved domain, three HMG-CoA binding sites at the C-terminus and seven transmembrane domains at the N-terminus. Phylogenetic analysis showed that SfHMGR has the closest genetic relationship with HMGR of Laodelphax striatellus and Nilaparvata lugens, showing 92.40% and 89.25% amino acid sequence identities with them, respectively. The developmental expression profiles showed that SfHMGR was highly expressed in the middle of various developmental stages and newly emerged female adults. The tissue expression profiles showed that SfHMGR was expressed in various tissues of female adults, and had the highest transcription level in gut. After the inhibition of SfHMGR expression by microinjection of dsRNA, the number of eggs laid by per female and ovarian development of female adults, and the transcription levels of SfJHAMT, SfFAMeT, SfKr-h1, SfVg and SfVgR were significantly inhibited. 【Conclusion】SfHMGR regulates the transcription level of SfVg by affecting the JH biosynthesis process and JH signal transduction, and then affects the ovarian development and the fecundity of female adults of S. furcifera.

【Aim】 ATP-binding cassette transporter (ABC transporter), a huge superfamily of membrane transporters, plays an important role in insect growth, development and insecticide resistance. This study aims to provide theoretical basis for subsequent functional studies by cloning ABCD1 of the white-backed planthopper, Sogatella furcifera and determining its expression pattern under insecticide stress. 【Methods】 The cDNA sequence of ABCD1 of S. furcifera was cloned by RT-PCR, and subjected to bioinformatics analysis. The expression levels of ABCD1 in S. furcifera at different developmental stages (1st-5th instar nymphs and 1-4 day-old male and female adults), in different tissues (head, integument, fat body, gut, leg, wing, testis and ovary) of the 5th instar nymphs and adults, and in the 3rd instar nymphs exposed to different concentrations (LC₁₀, LC₂₅, LC₅₀ and LC₉₀) of thiamethoxam, buprofezin, and abamectin were detected by RT-qPCR. 【Results】 An ABC transporter gene of S. furcifera was obtained and named SfABCD1 (GenBank accession no.: MW701394), with an open reading frame of 2 220 bp in length. It encodes a putative protein of 739 amino acid residues with the predicted molecular weight of 82.08 kD and isoelectric point of 9.32. SfABCD1 is closely related to ABCD1 of Laodelphax striatellus and Nilaparvata lugens. RT-qPCR results showed that SfABCD1 had the highest expression level in the 5th instar nymphs and was expressed in various tissues of the 5th instar nymphs and adults with the highest expression level in the gut and head of the 5th instar nymphs. After the 3rd instar nymphs were exposed to insecticides for 48 h, the expression levels of SfABCD1 in the treatment groups of buprofezin at the concentrations of LC₁₀, LC₅₀ and LC₉₀, thiamethoxam at the concentrations of LC₁₀, LC₂₅ and LC₅₀ and abamectin at the concentrations of LC₅₀ and LC₉₀ were significantly up-regulated as compared to that in the control group treated with water. When the 3rd instar nymphs were exposed to the three insecticides at the four concentrations of LC₁₀, LC₂₅, LC₅₀ and LC₉₀ for different time, the expression difference of SfABCD1 in the nymphs between the treatment group and the control group were the largest at 48 h after treatment and subsequently decreased at 96 h after treatment, and then the expression level of this gene in nymphs at 120 h after treatment was close to that in the control group. 【Conclusion】 S. furcifera can respond to the stress of buprofezin and thiamethoxam by up-regulating the expression of SfABCD1, and the expression level of SfABCD1 decreases with the increase of the concentration of thiamethoxam. In addition, S. furcifera also responds to the poison of high concentrations of abamectin by regulating the transcription level of SfABCD1.

【Aim】Notonecta chinensis, distributed in China and Okinawa of Japan, is an important aquatic natural enemy insect which can be used for biological control of mosquitoes. The purpose of this study is to establish the transcriptome database of N. chinensis, and to mine its genetic information. 【Methods】The transcriptome of N. chinensis was sequenced, de novo assembled and subjected to bioinformatics analysis by using the Illumina NextSeq500 high-throughput sequencing platform. New SSR molecular markers were selected by using MISA software based on the transcriptome unigenes data. Polymorphism of SSRs was detected by capillary electrophoresis. 【Results】A total of 34 782 282 clean reads (NCBI SRA accession number: SRR13259254) were obtained, and assembled into 37 801 unigenes with the N50 length of 913 bp. All unigenes were aligned against the known databases for gene function annotation, and 36 474, 32 470, 27 781, 35 079 and 5 638 sequences were annotated in nr, SwissProt, GO, eggNOG and KEGG databases, respectively. According to GO database annotation, the function of the unigenes can be divided into three categories including biological process, cellular component and molecular function, among which unigenes involved in cell, cell part and binding were enriched to a higher degree. eggNOG database annotation results showed that 37 801 unigenes were classified into 25 gene families, with the most annotated to function unknown. Enrichment analysis of KEGG metabolic pathways showed that 5 638 unigenes were annotated to 245 metabolic pathways, and the number of annotations to ribosome was the largest. Moreover, a large-scale SSR search was performed for 37 801 unigenes on the transcriptome sequencing data using the software MISA, and a total of 3 124 SSR loci (accounting for 8.26%) were identified, with a frequency of 7.07%. A total of 16 SSR loci were screened by PCR. The polymorphic information content (PIC) of the three loci NcCF/NcCR, NcKF/NcKR and NcLF/NcLR in seven geographical populations of N. chinensis were 0.870, 0.902 and 0.857, respectively, indicating high polymorphism. 【Conclusion】In this study, we successfully obtained the reference transcriptome of N. chinensis, which provides a molecular theoretical basis for its gene function analysis. The development of these potential SSR markers could provide a set of candidate molecular markers for genetic diversity analysis, cryptic species identification and genetic mapping construction of N. chinensis.

【Aim】 This study aims to clarify the expression profiles of nine microRNAs (miRNAs) in the grain aphid, Sitobion avenae at different developmental stages between winged and wingless morphs, and to define the key stage of the aphid wing dimorphism. 【Methods】The full-length cDNA of the reference gene U6 and nine miRNAs of S. avenae were cloned by using RT-PCR. The expression levels of nine miRNAs were detected in winged and wingless S. avenae at different developmental stages (pseudo embryo, 1st-4th instar nymph and adult) by using qRT-PCR. 【Results】The full-length cDNA of U6 of S. avenae is 92 bp and shows over 80% nucleotide sequence identity with U6 from other reported insects. qRT-PCR results revealed that most miRNAs had low relative expression levels in the pseudo embryo and nymphal stages, and high relative expression levels at the adult stage. The relative expression levels of six miRNAs (miR-277, miR-9a, miR-7, Let-7, miR-1 and miR-315) in winged adults were higher than those in wingless adults. MiR-277 and miR-9a had higher relative expression levels in winged adults. Except miR-315, the relative expression levels of five miRNAs including miR-277, miR-9a, miR-7, Let-7 and miR-1 in S. avenae at the adult stage showed significant difference between the winged and wingless morphs. Moreover, there were significant differences in the relative expression levels of miR-9a in the pseudo embryo and miR-315 in the 3rd instar nymphal stage between the winged and wingless morphs. The other three miRNAs (miR-8, PC-3p-2743_844 and PC-5p-113190_15) showed higher relative expression levels in wingless adults than in winged adults. The relative expression levels of miR-8 and PC-3p-2743_844 in winged and wingless adults were significantly higher than those in the other developmental stages, and that of PC-5p-113190_15 in the 3rd nymphs of wingless aphid was significantly higher than those in the other developmental stages. The relative expression levels of miR-8 in the adult stage and PC-3p-2743_844 in the pseudo embryo and adult stages showed significant difference between the winged and wingless morphs, and that of PC-5p-113190_15 in the 3rd nymphal stage showed extremely significant difference between winged and wingless morphs. 【Conclusion】The reference gene U6 of S. avenae is highly conserved among insects. The expression profiling results suggest that nine miRNAs may regulate the wing-morph differentiation of S. avenae during the pseudo embryo and adult stages.

【Aim】The Italian honey bee (Apis mellifera ligustica) is a subspecies of the western honeybee, Apis mellifera, which has excellent production performance. This study aims to reveal the molecular mechanism underlying metamorphosis during pupal stage regulated by three microRNAs (miRNAs) ame-miR-13b, ame-miR-100 and ame-miR-bantam using molecular biological approaches.【Methods】Stem-loop RT-PCR was used to confirm the true expression of ame-miR-13b, ame-miR-100 and ame-miR-bantam in A. m. ligustica workers at the pupal stage. RT-qPCR was performed to survey the expression profiles of ame-miR-13b, ame-miR-100, ame-miR-bantam and their target mRNAs during the pupal development process of A. m. ligustica worker. Related bioinformatic software was used to predict target mRNAs of ame-miR-13b, ame-miR-100 and ame-miRbantam in A. m. ligustica workers at the pupal stage, to construct and analyze miRNA-mRNA regulation network, and to conduct annotation of target mRNAs in databases.【Results】The results revealed that ame-miR-13b, ame-miR-100 and ame-miR-bantam were truly expressed during the pupal development process of A. m. ligustica worker, and the overall expression displayed an up-regulation trend. The three miRNAs mentioned above could respectively target 850, 136 and 506 mRNAs, and complex regulatory network formed among these miRNAs and their target mRNAs,which could be respectively annotated to 32, 24 and 33 GO terms, and 204, 114 and 171 KEGG pathways.【Conclusion】ame-miR-13b, ame-miR-100 and ame-miR-bantam potentially regulate the expression of ecdysone gene, yellow gene and genes related to Hippo, FoxO, Wnt, Jak-STAT and Notch signaling pathways, further affecting metamorphosis during the pupal development process of A. m. ligustica worker.

【Aim】 This study aims to identify and analyze transcription factors (TFs), fusion genes and RNA editing events in Ascosphaera apis mycelium (AaM) and spore (AaS) based on previously obtained PacBio single molecule real-time (SMRT) sequencing data, so as to further enrich the relevant information of A. apis and to offer theoretical basis for further investigation of their function. 【Methods】 Full-length transcripts in AaM and AaS were respectively aligned against Nr, Swiss-Prot and KEGG databases using BLASTx tool to gain protein sequences with the highest identity, which were then aligned to Plant TFdb database with hmmscan software to obtain the information of classification and annotation of TFs. Additionally, fusion_finder.py program contained in TOFU software was used for prediction of fusion genes, followed by analysis of their sequence and location information. RNA editing events in AaM and AaS were predicted using SAMtools, and then annotation of RNA editing events was performed with ANNOVAR software. Further, GO function and KEGG pathway annotation of genes located at the RNA editing sites was conducted using related bioinformatics software. 【Results】 A total of 213 TFs from 17 TF families were identified in AaS, and the C2H2 family was the largest. In AaM and AaS, 921 and 510 fusion genes were respectively identified. Additionally, in AaM and AaS, there were 510 shared fusion genes, while the numbers of specific ones were 411 and zero, respectively. In total, 547 and 191 RNA editing events were respectively identified in AaM and AaS, among them synonymous single nucleotide mutation was the most abundant type in AaM, while nonsynonymous single nucleotide mutation was the most abundant type in AaS. Moreover, 12 types of base substitution were identified in AaM, and the number of RNA editing events with C->T was the highest (158), while nine types of base substitution were identified in AaS, and the numbers of RNA editing events with C->T and G->T were the highest (both 42). In AaM and AaS, genes located at the RNA editing sites were involved in 19 and 24 GO functional terms as well as 11 and 20 KEGG pathways, respectively. 【Conclusion】 There are abundant TFs, fusion genes and RNA editing sites in mycelium and spore of A. apis. C2H2 family of TF has potential relationship with growth, development and cellular activity of mycelium and spore of A. apis. The base substitution types of RNA editing events in A. apis and other species are species-specific. RNA editing may play a role in growth and metabolism of mycelium and spore of A. apis.

【Aim】Habitat types and environmental factors have an important effect on species distribution and maintenance. In this study, the effects of different habitat types on butterfly community diversity and community structure, as well as the effects of environmental factors on butterfly species richness and abundance, were analyzed to lay a foundation for the study on the maintenance mechanism of butterfly diversity on varying regional scale.【Methods】In August and October 2019, we investigated the species of butterflies in five habitats including natural forest, secondary forest, complex habitat, artificial forest and farmland, by using the transect-line method in Xishuangbanna area, Yunnan, southwestern China, and analyzed the diversity of butterfly communities, community structure similarity and the relationship of species richness and abundance with environmental factors.【Results】A total of 2 226 butterflies were collected in Xishuangbanna in 2019, belonging to 175 species, 98 genera, and 11 families. The species richness of butterflies on Xishuangbanna prefecture-level scale was higher than that in county scale. On Xishuangbanna prefecture-level scale, there were significant differences in the species richness and abundance of butterflies among the five habitats, while on county scale, the species richness, abundance, and Chao 1 species richness estimate values showed no consistent rule. The similarity results of the community structure showed that there were extremely significant differences in the community structure of butterflies on Xishuangbanna prefecture-level scale among different habitat types. On county scale, only the butterfly community structure in Mengla was significantly different among different habitat types. This study also revealed that butterfly species richness and abundance were affected not only by habitat types, but also by temperature, average annual precipitation and altitude.【Conclusion】These results suggest that habitat types have a greater impact on the diversity of butterflies in Xishuangbanna, while temperature, average annual precipitation and altitude are important factors of maintaining the diversity of butterfly species on varying regional scales. These findings have important implications for biodiversity conservation in the current era of human-induced habitat loss and climate change.

 【Aim】 To investigate the effects of seed soaking with different concentrations of calcium chloride (CaCl₂) on rice defense enzyme activities and resistance to the brown planthoppers (BPH), Nilaparvata lugens. 【Methods】Rice seeds were respectively soaked in 10, 20, 30, 40 and 50 mmol/L CaCl₂ solution for 48 h, and the control seeds were soaked in distilled water. At the tillering stage, the activities of phenylalanine ammonia lyase (PAL), peroxidase (POD), polyphenol oxidase (PPO) and β-1, 3-glucanase (β-1,3-GA) in leaf sheaths of rice plants pretreated by soaking seeds in various concentrations of CaCl₂ with or without infestation by the 3rd instar nymphs of BPH were tested, and the survival rates of the 2nd instar nymphs of BPH fed on rice plants subjected to seed soaking treatment with different concentrations of CaCl₂, calcium chelator ethylene glycol tetraacetic acid (EGTA)(1 mmol/L) plus 20 mmol/L CaCl₂ and ion channel inhibitor lanthanum chloride (LaCl₃)(1 mmol/L) plus 20 mmol/L CaCl₂, respectively, for 7 d were examined as well.【Results】 Without BPH infestation, the activities of PAL, POD, PPO and β-1,3-GA in rice leaf sheaths in seed soaking treatments with various concentrations of CaCl₂ showed no significant differences from those of the control. When the rice plants were infested by the 3rd instar nymphs of BPH, the activities of these four defense enzymes in leaf sheaths of CaCl₂-pretreated rice plants and the control rice plants all increased significantly, while the ascending degrees of all enzyme activities in CaCl₂-pretreated rice plants were higher than those in the control plants. The effects of seed soaking with different concentrations of CaCl₂ on the activities of various enzymes in leaf sheaths of rice plants under BPH infestation were different, the activities of PAL, POD and PPO in seed soaking treatment with 30 mmol/L CaCl₂ were 104.88%, 94.32% and 61.84% higher than those in their respective controls, respectively, and the β-1,3-GA activities in seed soaking treatment with 10 and 20 mmol/L CaCl₂ were 27.75% and 33.04% higher than those in their respective controls, respectively. After 7 d, the survival rates of the 2nd instar nymphs of BPH fed on the rice plants subjected to seed soaking treatment with 10, 20 and 30 mmol/L CaCl₂ were 32.68%, 22.54% and 30.28% lower than that fed on the control plants, respectively, but the survival rates of BPH nymphs fed on the plants subjected to seed soaking treatment with 40 and 50 mmol/L CaCl₂ showed no significant differences from that fed on the control plants. Additionally, calcium chelator EGTA (1 mmol/L) and ion channel inhibitor LaCl₃ (1 mmol/L) significantly inhibited the effects of CaCl2 (20 mmol/L) on induced resistance in rice plants to BPH, and the survival rates of nymphs fed on rice plants subjected to seed soaking treatment with EGTA+CaCl₂ and LaCl₃+CaCl₂ were 25.80% and 22.12% higher than that fed on rice plants subjected to seed soaking treatment with CaCl₂, respectively.【Conclusion】 Seed soaking treatment with CaCl₂ can prime rice plants in a stage of preparing for defense, resulting in higher enzyme activities when attacked by BPH, and thus increasing rice resistance against BPH.

【Aim】 Aphelinus maculatus is a newly recorded species in China in 2016, and one of the most important parasitoids of the peach aphid, Myzus persicae. In order to evaluate the control ability of A. maculatus to M. persicae scientifically,we investigated the effects of the ovipositor stabbing of A. maculatus on the survival, development and fecundity of its host peach aphid. 【Methods】 M. persicae aphids stabbed by the ovipositor (ovipositor insertion into aphid body and withdrawing out once) of A. maculatus were reared individually on the rape leaf-let in the petri-dish. The number of survival individuals, number of parasitized individuals, and number of death individuals of M. persicae, and the development and reproduction of the survivors were recorded daily until the death of the aphid.【Results】The effects of the ovipositor stabbing of A. maculatus on peach aphid included lethal, survival and parasitism. The mortality of peach aphid stabbed by the ovipositor of A. maculatus decreased with the increase of peach aphid age, and that of the 1-day-old nymphs stabbed by ovipositor of A. maculatus was the highest (45%). The longer the stabbing time, the higher the mortality of the peach aphid. The survival rate of peach aphid and parasitism rate of A. maculatus increased with the increase of the peach aphid age. The nymphal survival period and pre-reproduction duration of survival peach aphid were longer than that of the control (not being stabbed), but the reproduction duration and post-reproduction duration were significantly shorter than that of the control. The reproduction duration of the 3-day-old nymphs stabbed by the ovipositor of A. maculates was the shortest, being shortened by 13.7±1.7 d as compared to that of the control. The adult longevity of survivors of the peach aphid stabbed by the ovipositor of A. maculatus was significantly shortened and related to the age of peach aphid when being stabbed. The adult longevity of the 2-day-old and 3-day-old nymphs stabbed by the ovipositor of A. maculates was impacted greatly, being shortened by 12.5 and 11.2 d, respectively, as compared to that of the control. The fecundity (number of offspring produced per aphid) of the stabbed survivors decreased significantly, and the younger the stabbed age, the fewer the fecundity. The stabbed survivors from the 1dayold nymphs and adults produced 39.1±4.9 and 25.2±2.7 offspring fewer than their nonstabbed controls, respectively. 【Conclusion】In addition to parasitism and feeding on peach aphid, ovipositor stabbing (unsuccessful parasitization) by A. maculatus will prolong the growth and development phase of survival peach aphid and reduce its life span and fecundity. These effects of the ovipositor stabbing of A. maculatus on the survival, development and fecundity of its host may play important roles in evaluation of its aphid control ability.

 【Aim】 The typical single-chromosome mitochondrial (mt) genome of animals has fragmented into multiple mt minichromosomes in Hoplopleura genus. To infer the ancestral mt karyotype for Hoplopleura genus, we sequenced the mt genome of Hoplopleura pacifica. 【Methods】 We sequenced the fragmented mt genome of H. pacifica by Illumina HiSeq X Ten platform, and analyzed the structure and variation. We constructed phylogenetic trees of 15 species of sucking lice in 7 genera and 7 families by using maximum likelihood method and neighbor-joining method, and inferred the ancestral mt karyotype of Hoplopleura by parsimony method. 【Results】 We identified 29 mt genes (11 protein-coding genes, 16 tRNA genes and 2 rRNA genes) from mt genome of H. pacifica, which are unevenly distributed on 10 mt minichromosomes. The coding region of each mt minichromosome contains 1-5 genes with the length of 690-1 773 bp. Species of Hoplopleura have a little difference in structure of mt minichromosomes. Compared with other genera in Anoplura, Hoplopleura have variation in the gene composition and gene arrangement of mt minichromosome, which, however are only limited to tRNA genes. The phylogenetic tree showed that Anoplura was divided into two major clades with strong supports, one major clade included the lice of Hoplopleuridae, Polyplacidae, Haematopinidae and Microthoraciidae, and the other major clade included the lice of Pediculidae, Pthiridae, and Pedicinidae. The ancestral mt karyotype of Hoplopleura comprises 12 mt minichromosomes, each having a single coding region with 1-6 genes and a single non-coding region. 【Conclusion】 We successfully sequenced and analyzed the fragmented mt genome of H. pacifica for the first time, compared it with the mt genome of the other two Hoplopleura species sequenced to date, and inferred the ancestral mt karyotype of Hoplopleura.

【Aim】 The Colorado potato beetle, Leptinotarsa decemlineata is an important quarantine pest in China, and it has serious harm to Solanaceae plants. This study aims to clarify the effects of late spring coldness and short-term low temperature on the growth of L. decemlineata population. 【Methods】 L. decemlineata eggs were exposed to low temperature of 8℃ for 1, 3 and 5 d, and those cultured at 27℃ were used as the control, and the egg hatching rate, growth and development of larvae and adult reproduction were investigated. The effects of short-term low temperature on the population growth of Colorado potato beetles were evaluated by population parameters.【Results】 When L. decemlineata eggs were exposed to low temperature of 8℃, the egg duration was significantly prolonged with the treatment time. The egg hatching rates in the treatment groups of 3 d and 5 d were significantly lower than that of the control, and the 1st instar larval duration in these two treatment groups was significantly longer than that of the control. However, the 2nd, 3rd and 4th instar larval and pupal duration was not significantly affected by the low temperature treatment of 8℃. After L. decemlineata eggs were exposed to low temperature of 8℃ for 5 d, the survival rates of the 1st instar larvae and adults were significantly lower than that of the control, but those of the other developmental stages in various treatment groups showed no significant difference. After L. decemlineata eggs were exposed to low temperature of 8℃ for 3 d, the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R₀) of population were significantly lower than those of the control and exposed to low temperature for 1 d, but the mean generation time (T) in various treatment groups were not significantly different.【Conclusion】Short-term low temperature stress has adverse effects on the growth and development of L. decemlineata and slows down its population growth.