Rice Planthoppers Research Articles

Tolerance against brown planthopper (Nilaparvata lugens) in wild rice (Oryza sativa) accessions

Brown planthopper, Nilaparvata lugens (Stål), is a major insect pest of rice in all the rice growing areas of the world. In the present study, the tolerance mechanism of resistance in wild rice accessions belonging to different Oryza species such as O. nivara (IRGC104646, CR100204), O. australiensis (IRGC105275, IRGC105270), O. punctata (IRGC99577) along with resistant check, Ptb33 and susceptible check, TN1 has been studied. The experiments were carried out on 30-days old plants under glasshouse conditions during kharif 2017 and 2018. IRGC99577 (22.80 and 24.00) took maximum days to hopper burn condition during both seasons. Functional plant loss index (%) was minimum in IRGC99577 (18.10%) followed by Ptb33 (20.96%) and IRGC104646 (29.47%). Least plant dry weight loss index (mg) was observed in Ptb33 and highest in TN1 during both the seasons. Overall, results indicated that rice accessions, IRGC99577 and IRGC104646 showed high levels of tolerance as compared to other wild rice accessions that were tested. The identified accessions thus could serve as potential sources of resistance in breeding BPH resistant varieties.

CPR Gene Contributes to Integument Function and Ovary Development in a Rice Planthopper.

Nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P450 reductase (CPR) is an essential enzyme that transfers electrons from NADPH to cytochrome P450 monooxygenases. CPR is involved in cuticular hydrocarbon (CHC) synthesis in insects and is vital for insect development and survival. Here, we clarify the physiological function of a CPR gene in Nilaparvata lugens, an important rice pest, by using RNA interference. CPR gene knockdown leads to the functional loss of waterproofing and water retention in the integument of female adults, which causes significantly reduced body weight and a lethal phenotype. Scanning electron microscopy shows that the lipid layer on the outermost surface of the abdominal cuticle becomes thin in dsCPR-injected adults. Furthermore, CHC profile analysis reveals that CPR knockdown significantly decreases the contents of CHCs with a carbon chain length ≥ C27 in adult females. Moreover, we find that CPR knockdown generates a deficient phenotype in ovaries with deformed oocytes and a complete failure of egg-laying. These findings suggest that CPR plays multiple functional roles in CHC biosynthesis and embryo development in insects.

Spatial and temporal patterns of rice planthopper populations in South and Southwest China

Rice planthoppers (RPH) are important pest that cause severe yield losses of rice production in China. South and Southwest China are the main infestation areas on the annual spread of RPH. Identifying the spatial and temporal patterns in migration and subsequent development can provide insight into underlying mechanisms driving the spread of RPH and assist governments with prioritizing areas to achieve proactive management and prevention. Across rice production regions in South and Southwest China, RPH population were recorded by light traps and field surveys at 195 counties from March to October in 2000 to 2019. We first measured the spatial patterns in RPH immigrant populations and field populations with spatial autocorrelation analysis. Then, spatial hotspot analysis was undertaken to highlight dense RPH regions, and significant hot spots were further extracted for comparing the spatial and temporal patterns according to RPH species. The results revealed that RPH population were highly aggregated in space over large geographical distances up to 700 km approximately. Geographic patterns and hot spots of populations varied substantially with time and species, and various spatial patterns might be determined by inherent properties of RPH and rice eco-systematic. Overall, these results provided essential information to improving and optimizing the monitoring network for RPH. The findings from this research may provide helpful information to enhance proactive management against RPH and offer sustainable management practitioners new opportunities to design, develop, and implement optimal pest control strategies to protect rice production in China.

Transcriptome analysis and molecular characterization of soluble chemical communication proteins in the parasitoid wasp Anagrus nilaparvatae (Hymenoptera: Mymaridae).

Anagrus nilaparvatae is an important egg parasitoid wasp of pests such as the rice planthopper. Based on the powerful olfactory system of sensing chemical information in nature, A. nilaparvatae shows complicated life activities and behaviors, such as feeding, mating, and hosting. We constructed a full‐length transcriptome library and used this to identify the characteristics of soluble chemical communication proteins. Through full‐length transcriptome sequencing, splicing, assembly, and data correction by Illumina, we obtained 163.59 Mb of transcriptome data and 501,179 items with annotation information. We then performed Gene Ontology (GO) functional classification of the transcriptome's unigenes. We analyzed the sequence characteristics of soluble chemical communication protein genes and identified eight genes: AnilOBP2, AnilOBP9, AnilOBP23, AnilOBP56, AnilOBP83, AnilCSP5, AnilCSP6, and AnilNPC2. After sequence alignment and conserved domain prediction, the eight proteins encoded by the eight genes above were found to be consistent with the typical characteristics of odorant‐binding proteins (OBPs), chemosensory proteins (CSPs), and Niemann‐pick type C2 proteins (NPC2s) in other insects. Phylogenetic tree analysis showed that the eight genes share low homology with other species of Hymenoptera. Quantitative real‐time polymerase chain reaction (RT‐qPCR) was used to analyze the expression responses of the eight genes in different sexes and upon stimulation by volatile organic compounds. The relative expression levels of AnilOBP9, AnilOBP26, AnilOBP83, AnilCSP5, and AnilNPC2 in males were significantly higher than those in females, while the relative expression level of AnilCSP6 was higher in females. The expression levels of AnilOBP9 and AnilCSP6 were significantly altered by the stimulation of β‐caryophyllene, suggesting that these two genes may be related to host detection. This study provides the first data for A. nilaparvatae's transcriptome and the molecular characteristics of soluble chemical communication proteins, as well as an opportunity for understanding how A. nilaparvatae behaviors are mediated via soluble chemical communication proteins.

Rice Defense against Brown Planthopper Partially by Suppressing the Expression of Transferrin Family Genes of Brown Planthopper.

Transferrins are multifunctional proteins, but their role in the interaction of rice and brown planthopper (BPH) remains unclear. In this study, the full-length cDNA of transferrin genes NlTsf1, NlTsf2, and NlTsf3 was cloned. Reverse transcription quantitative polymerase chain reaction showed that the expressions of NlTsf1 and NlTsf3 were significantly suppressed in BPH reared on the resistant rice R1 by 68.0 and 86.7%, respectively, compared with that on the susceptible S9. The survival rate decreased to 3.3% for dsNlTsf3-treated nymphs, to 58.9% for dsNlTsf1, and to 56.7% for dsNlTsf2 on day 11. RNAi of NlTsf3 against females largely reduced the number of eggs by 99.4%, and it decreased by 48.6% for dsNlTsf1 but did not significantly decrease for dsNlTsf2. Collectively, NlTsf1, NlTsf2, and NlTsf3 are essential for the survival and fecundity of BPH and are differentially involved in the interaction between rice and BPH. Therefore, NlTsf1 and NlTsf3 may be used as targets to control BPH.

Bio-Efficacy of Chrysoeriol7, a Natural Chemical and Repellent, against Brown Planthopper in Rice.

Brown planthopper (BPH, Nilaparvata lugens Stal.) is the most damaging rice pest affecting stable rice yields worldwide. Currently, methods for controlling BPH include breeding a BPH-resistant cultivar and using synthetic pesticides. Nevertheless, the continuous cultivation of resistant cultivars allows for the emergence of various resistant races, and the use of synthetic pesticides can induce environmental pollution as well as the emergence of unpredictable new pest species. As plants cannot migrate to other locations on their own to combat various stresses, the production of secondary metabolites allows plants to protect themselves from stress and tolerate their reproduction. Pesticides using natural products are currently being developed to prevent environmental pollution and ecosystem disturbance caused by synthetic pesticides. In this study, after BPH infection in rice, chrysoeriol7 (C7), a secondary metabolite that induces resistance against BPH, was assessed. After C7 treatment and BPH infection, relative expression levels of the flavonoid-related genes were elevated, suggesting that in plants subjected to BPH, compounds related to flavonoids, among the secondary metabolites, play an important role in inducing resistance. The plant-derived natural compound chrysoeriol7 can potentially thus be used to develop environmentally friendly pesticides. The suggested control of BPH can be effectively used to alleviate concerns regarding environmental pollution and to construct a relatively safe rice breeding environment.

Resistance of Lepidopteran Egg Parasitoids, Trichogramma japonicum and Trichogramma chilonis, to Insecticides Used for Control of Rice Planthoppers.

Trichogramma wasps are commonly used as biocontrol agents to manage lepidopteran rice pests in rice fields. However, lepidopteran pests synergistically occur with rice planthoppers which are not targeted by Trichogramma. The use of Trichogramma parasitoids in field-based pest control efforts is greatly affected by the application of insecticides targeting planthoppers. As such, insecticide-resistant strains of Trichogramma are urgently needed for the incorporation of these beneficial natural enemies into integrated pest management programs in rice agroecosystems. In the present study, Trichogramma japonicum Ahmead (Hymenoptera: Trichogrammitidae) and Trichogramma chilonis Ishii (Hymenoptera: Trichogrammitidae) were treated with sublethal doses of four insecticides which target rice planthoppers, to generate tolerant strains in the laboratory. The resistance rate of T. japonicum to imidacloprid was the highest (17.8-folds) after 10 successive treatments and experienced 2.5, 4.72, and 7.41-fold increases in tolerance to thiamethoxam, buprofezin, and nitenpyram, respectively. Tolerance of T. chilonis to imidacloprid, thiamethoxam, buprofezin, and nitenpyram were 8.8, 6.9, 4.43, and 5.67-fold greater, respectively. The emergence and deformity (without spreading wings or short wings) rates of T. japonicum and T. chilonis gradually recovered with an increased exposure time of treatments. The fecundity of T. japonicum treated with thiamethoxam was significantly higher than that of the control and T. chilonis treated with thiamethoxam and nitenpyra. Our results demonstrate that screening for insecticide-tolerant/resistant Trichogramma strains was feasible, especially in the pairing of T. japonicum and imidacloprid, which could provide a valuable biological control tool that can be combined with traditional chemical control strategies for use in IPM of rice agroecosystems.

Residue dynamics and bio-efficacy of triflumezopyrim against Nilaparvata lugens and non-targeted effect on natural enemies in a rice ecosystem.

Triflumezopyrim (TMP), a mesoionic insecticide, is commonly used for controlling planthoppers in rice. However, the relationship between the TMP residue and toxicity against brown planthoppers (BPHs) has not been studied in detail. We are reporting the dissipation of TMP from rice plant and soil under field conditions. The median lethal dose and median lethal concentration were 0.036ng per insect and 0.525mg L-1, respectively. TMP at recommended dose (25g a.i. ha-1) recorded 1.25 live BPH per hill as against 25.5 per hill in control at 14days after treatment. TMP was considered to be harmless to the natural enemies, namely, Cyrtorhinus lividipennis and Lycosa pseudoannulata in the rice ecosystem. The residue of TMP from rice plant and soil was estimated using the QuEChERS method using three different doses (12.5, 25, and 50g a.i. ha-1). The limit of quantitation (LOQ) of TMP in plant and soil was 5µgkg-1 and 1µgkg-1, respectively. The maximum content of TMP in soil was less than 1% that of plant content on day 1. The dissipation pattern of TMP both from plant and soil was better explained by the first-order double-exponential decay model (FODED) as compared to the first-order kinetic model. Overall, the half-lives of TMP were ranged from 2.21 to 3.02days in plant tissues and 3.78 to 4.79days in soil as per the FODED model. Based on the persistence and toxicity of TMP, we could conclude that TMP will be effective against BPH up to 7-10days after application. Triflumezopyrim with reasonable persistence and high efficacy could be recommended as an alternate pesticide in BPH management in rice.

Efficacy of dinotefuran 20 SG against brown planthopper (Nilaparvata lugens Stål) in basmati rice

Brown planthopper, Nilaparvata lugens StÃ¥l is a dominant species among the noxious rice pests and causes considerable damage in India. Various strategies have been employed to manage brown planthopper and insecticides factor as the frontline defense. However, it has now become difficult to manage brown planthopper with the present genre' of insecticides due to the development of resistance. Identification of new molecules with selective properties, a novel mode of action, low toxicity to non-targets and environmental safety becomes a newer tool for the sustainable management of brown planthopper. In this direction, dinotefuran 20 SG a new molecule was evaluated under field conditions to access its efficacy against brown planthopper in basmati rice during Kharif, 2019. Results of the present investigations indicated that dinotefuran 20 SG at 40 g a.i./ha as a spray (when pest crosses ETL) was  the effective treatment in the reduction of brown plant hopper population. The added advantages included non phytotoxicity of foliar application of dinotefuran 20 SG @ 40  g a.i. ha-1 to the paddy crop. Mean  grain yield (38.1  q ha-1) was recorded in dinotefuran 20 SG sprayed plots as compared to control (32.3 q ha-1) and increase in grain yield over control was recorded to be 15.5 per cent.Â

Biological activity of benzpyrimoxan insecticide against plant hoppers in rice

Biological activity of benzpyrimoxan insecticide against plant hoppers in rice

Assessment of IPM module on brown planthopper incidence in rice crop

The experiment was carried out in 4.0 ha with active participation of farmers with an objective to assess the integrated management module for the management of brown planthopper in rice for three years. Maximum temperature, morning relative humidity, rainfall and evening relative humidity favours BPH population. Minimum temperature impacted the BPH. The mean incidence of BPH population/hill was lower in IPM module (2.97 and 12.03 at tillering and panicle initiation stage respectively) as compared to farmers practice (13.34 and 30.62 at tillering and panicle initiation stage respectively). The mean yield of IPM module was 70.7 q/ha with net returns and C:B ratio of Rs. 62604/ha and 1:2.15, respectively. Whereas, farmer's practice recorded a mean yield of 61.5 q/ha with net returns and C:B ratio of Rs. 48357/ha and 1:1.89, respectively. The increase in yield over farmer's practice was 14.9%.

Evaluation of Detection Accuracy of Image Recognition for Automatic Counting of Rice Planthoppers Captured on Sticky Boards

Evaluation of Detection Accuracy of Image Recognition for Automatic Counting of Rice Planthoppers Captured on Sticky Boards

The vertical distribution and temporal occurrence of three types of rice planthoppers in Shanghai

AbstractIn this study, we investigated the dynamic occurrence and vertical distribution of three types of rice planthoppers (Nilaparvata lugens, Sogatella furcifera, and Laodelphax striatellus) in Shanghai, China. Our results showed that S. furcifera and L. striatellus infested the lower part of rice plants in the early development stage, S. furcifera and L. striatellus inhabited every part of rice in the middle development stage, and L. striatellus and N. lugens formicated in the upper part of the rice plant in the posterior development stage. The populations of rice planthoppers were larger in July and September, Where more than 600 adult and nymphal planthoppers, per a hundred hills of rice, were found in late July, and out of the 600, the majority were the nymphs of S. furcifera and L. striatellus. S. furcifera was mainly found from July to October, L. striatellus during the rice development, and N. lugens after September, during which their maximal individual number, per a hundred hills of rice, was 480, 220, less than 50, respectively. In addition, our results showed that adult rice planthoppers were mostly observed from late August to mid‐October with the highest population being found during mid to late September. The adult S. furcifera, L. striatellus, and N. lugens were mostly observed in August and September, from August to October, and past mid‐September, respectively. Moreover, the number of adult L. striatellus that were sticking to yellow sticky card was significantly higher than that of S. furcifera and N. lugens.

Establishment of White-Backed Planthopper Cell Lines.

The first continuous cell line of leafhopper was established over 50years ago. Since then, leafhopper cell monolayers have been used extensively to assay the infectivity of plant viruses that multiply in their insect vectors and to elucidate the viral determinants for virus transmission via insects. We have established continuous insect cell lines of three rice planthoppers, which have been used to study the mechanisms for replication and spread of rice viruses. The notable advantage of the vector cell monolayer system is that it can reach a uniform infection rate of 100% of the cells in the culture inoculated with diluted viruses, and thus allows for synchronous virus multiplication. The self-propagative nature of leafhopper and planthopper cell lines under favorable conditions ensures the system both dynamic and stable for viral infection. The vector cell monolayer systems and molecular probes, along with reliable traditional methods, certainly facilitate studies on interactions between plant viruses and insect vectors at molecular and cellular levels.

Bioactivities of Lamiaceae, Myristicaceae, and Myrtaceae plant oils against Nilaparvata lugens Stâl. (Hemiptera: Delphacidae)

Essential oil (EO) plants have properties as botanical insecticides. Some of them come from the families of Lamiaceae, Myristicaceae, and Myrtaceae. A plant belonging to the Lamiaceae includes patchouli (Pogostemon cablin), while the Myristicaceae includes nutmeg (Myristica fragrans), and the Myrtaceae includes clove (Syzygium aromaticum) and cajuput (Melaleuca cajuput subsp. cajuputi). This research aimed to evaluate toxicity, feeding inhibition, and oviposition deterrent from four EO plants from the Lamiaceae, Myristicaceae, and Myrtaceae to brown rice planthopper Nilaparvata lugens (Hemiptera: Delphacidae), the main pest of rice. The results showed that cajuput and patchouli oil gave more potent toxicity to N. lugens with LC50 and LC95 were 0.016% and 4.87% for cajuput oil and 0.019% and 5.25% for patchouli oil. Cajuput oil at 0.002% deterred oviposition 51.74% and inhibited feeding on 0.016% as many as 71.52% with strong enough criteria to the fourth instar nymphs of N. lugens. Patchouli oil deterred oviposition from 0.002% as much as 61.15% and inhibited feeding on 0.019% as many as 68.73% with strong enough criteria. The highest oviposition deterrent was 83.2% on patchouli oil at the concentration of 0.188%, whereas the highest feeding inhibition was 82.78% on cajuput oil at the concentration of 0.169%.

The role of 20E biosynthesis relative gene Shadow in the reproduction of the predatory mirid bug, Cyrtorhinus lividipennis (Hemiptera: Miridae).

Cytorhinus lividipennis is a natural enemy of rice planthoppers and leafhoppers. Improving the fecundity of C. lividipennis will be helpful to improve its control effect on pests. However, little is known about the hormonal regulatory mechanism of reproduction in C. lividipennis. In the current study, we examined the role of 20-hydroxyecdysone (20E) biosynthesis relative gene Shadow in the reproduction of C. lividipennis. The complementary DNA sequence of ClSad is 2018 -bp in length with an open reading frame of 1398-bp encoding 465 amino acid residues. ClSad was readily detected in nymphal and adult stages, and highly expressed in the adult stage. ClSad was highly expressed in the midgut and ovaries of adult females. Moreover, RNA interference-mediated knockdown of ClSad reduced the 20E titers and ClVg transcript level, resulting in fewer fully developed eggs and a decrease in the number of eggs laid by dsSad-injected adult females within 15 days. These results suggest that ClSad plays a critical role in the reproduction of C. lividipennis. The present study provides insights into the molecular mechanism of theClSad gene for the reproduction of C. lividipennis.

Controlled-release granules for the delivery of pymetrozine to roots of transplanted rice seedlings with decreased phytotoxicity and enhanced control efficacy against paddy planthoppers.

Seedling transplanting is widely used in rice cultivation. Systemic insecticides can be delivered to seedling roots by application through rice seedling boxes before transplanting. The most challenging aspect is to provide long-term control of rice pests and overcome transplanting shock. Precise control of the release rate of insecticide can meet these requirements. Pymetrozine is a promising insecticide used for the control of rice planthoppers resistant to neonicotinoid insecticides. In this study, four controlled-release granular formulations of pymetrozine were prepared based on a mixture of cost-effective and biodegradable kaolin and xanthan gum or a mixture of calcined kaolin and xanthan gum. Fluorescence images showed that different 3D networks were formed in the four granular formulations. The four granular formulations showed different water uptake rates and release rates of pymetrozine in water. Pymetrozine release rate was positively correlated with the water uptake capacity, rather than the water uptake rate of granules. Diffusion was the dominant mechanism for the release of pymetrozine from granules. Pymetrozine was found to reduce the survival of transplanted rice seedlings suffering from transplanting shock. Incorporating pymetrozine in controlled-release granules alleviated this phytotoxicity. The survival rate of rice seedlings in granular pymetrozine treatments ranged 68.8-85.0%, whereas the survival rate was <50% for powdered pymetrozine treatments. Additionally, four prepared granule formulations had a significant control effect on rice planthopper with efficacies ranging from 76.7% to 98.0% 40 days after seedling box treatment. The granule with an intermediate release rate of pymetrozine was shown to be more suitable for seedling box treatment than field application and traditional liquid spraying for the long-term control of paddy planthoppers. © 2021 Society of Chemical Industry.

Efficacy and Cost-Effectiveness of Phenotyping for Rice Resistance and Tolerance to Planthoppers.

Simple SummaryRice in Asia is damaged by a range of sap-sucking planthoppers. For the last 50 years, the main focus for integrated management of these insects was to develop resistant rice varieties. A single, bulk phenotyping test, known as the standard seedling seedbox test (SSST) was used to inform the majority of genetics and breeding programs for planthopper-resistant rice. However, there has been much debate over the efficacy of this test. We compared results from the SSST against those from a range of other phenotyping tests to assess how antibiosis and tolerance (the ability of rice to compensate for damage) affect test results, and how phenotyping might be improved to capture information regarding plant traits that are otherwise overlooked by the SSST. Based on the efficacy and costs of different tests, we recommend that breeding programs adopt a modified seedling seedbox test (MSST) when phenotyping 100s of rice lines but that insect performance tests that assess relative changes in planthopper biomass could be adopted when phenotyping fewer lines (e.g., <100 lines). The days-to-wilt (DTW) test was found to be particularly effective in segregating resistant/tolerant lines from susceptible lines.The standard seedling seedbox test (SSST) is the most prevalent phenotyping test in research on the genetics and breeding of planthopper-resistant rice. Using 16 rice lines that included plants susceptible, resistant and tolerant to the brown planthopper (Nilaparvata lugens), we compared the SSST to modified seedling seedbox tests (MSSTs) and the days-to-wilt (DTW) test. We also conducted a series of performance tests to assess nymph survival and development; adult longevity and egg-laying; egg survival; honeydew production; and plant weight loss. We also assessed the relative costs of the different phenotyping tests to better recommend test protocols that are suitable for high-throughput phenotyping. The SSST was found to be highly robust but fails to identify late-stage resistance; tolerance; or ovicidal responses. MSSTs improved phenotyping by identifying plants with low damage from planthoppers at later growth stages. Herbivore performance tests such as population or biomass build-up tests reduce space requirements and reduce setup and evaluation costs compared with bulk tests. They can also facilitate the assessment of plant tolerance; albeit with added costs. The DTW test most clearly segregates resistant and susceptible plants, thereby facilitating gene discovery and marker-assisted selection. We recommend that bulk testing be improved by switching from the SSST to a suitable MSST and that donor variety and pre-release lines be assessed for the nature of rice–planthopper interactions using biomass build-up tests—including the DTW test.

Two Newly Introduced Wolbachia Endosymbionts Induce Cell Host Differences in Competitiveness and Metabolic Responses.

Wolbachia endosymbionts can induce multiple reproductive manipulations in their hosts, with cytoplasmic incompatibility (CI) being one of the most common manipulations. Two important agricultural pests, the white-backed planthopper (Sogatella furcifera) and the brown planthopper (Nilaparvata lugens), are usually infected with CI-inducing Wolbachia strain wFur and non-CI-inducing Wolbachia strain wLug, respectively. The biological effects of these infections when present in a host cell are unknown. Here, we introduced the two Wolbachia strains into an Aedes albopictus cell line to stably establish a wFur-infected cell line (WFI) and a wLug-infected cell line (WLI). In a mixed culture, WFI cells were completely replaced by WLI cells, pointing to a stronger competitiveness of the WLI cell line. We found that infection by both Wolbachia strains reduced cell growth rates, but WLI had a higher cell growth rate than WFI, and this difference in cell growth rate combined with possible Wolbachia differences in diffusivity may have affected cell competitiveness. By examining gene expression and metabolites in the two lines, we found that some genes and key metabolites responded to differences in cell competitiveness. These results point to potential mechanisms that could contribute to the relative performance of hosts infected by these strains and also highlight the substantial impact of a non-CI Wolbachia on metabolism, which may in turn influence the fitness of its native host. IMPORTANCEWolbachia transinfection in insects can be used to suppress pests and block virus transmission. We stably introduced two Wolbachia strains from rice planthoppers into cell lines of an important arbovirus mosquito vector, Aedes albopictus. The levels of competitiveness of host cells from the lines infected by the two Wolbachia strains were different, as were metabolic responses of the cell lines. These results suggest potential metabolic effects of Wolbachia on native hosts that could be exploited when they are transinfected into novel hosts for pest control.

Silencing of a putative alanine aminotransferase (ALT) gene influences free amino acid composition in hemolymph and fecundity of the predatory bug, Cyrtorhinus lividipennis Reuter.

In Asian rice systems, Cyrtorhinus lividipennis Reuter is an important predator that preys on rice planthopper eggs and young nymphs, as a primary food source. Alanine aminotransferase (ALT) acts in many physiological and biochemical processes in insects. We cloned the full-length complementary DNA of C. lividipennis ClALT. Expression analysis showed higher expression in the fat body and midgut compared to other tissues. It is expressed in all C. lividipennis developmental stages and at least four organs. Silencing of ClALT by RNA interference significantly decreased the ClALT enzyme activity and ClALT expression compared to dsGFP-treated controls at 2 days after emergence (DAE). Silencing of ClALT influenced free hemolymph amino acid compositions, resulting in a reduction of Aspartic acid (Asp) and Alanine (Ala) proportions, and increased Cysteine (Cys) and Valine (Val) proportions in females at 2 DAE. dsClALT treatments led to decreased soluble total protein concentrations in ovary and fat body, and to lower reduced vitellogenin (Vg) expression, body weight, and the numbers of laid eggs. The double-stranded RNA viruse treatments also led to prolonged preoviposition periods and hindered ovarian development. Western blot analysis indicated that silencing ClALT also led to reduced fat body Vg protein abundance at 2 DAE. These data support our hypothesis that ClALT influences amino acid metabolism and fecundity in C. lividipennis.