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Article

Targeting the Type 1 Tyramine Receptor LsTAR1 Inhibits Reproduction, Feeding and Survival in the Small Brown Planthopper Laodelphax striatellus

by
Zihan Yan
,
Liran Fu
,
Yutong Chen
,
Kangjing Ye
,
Yuanyuan Zhang
,
Liang Wu
,
Ruhao Qian
,
Mingshi Qian
,
Guoqing Yang
and
Gang Xu
*
College of Plant Protection, Yangzhou University, Yangzhou 225009, China
*
Author to whom correspondence should be addressed.
Insects 2026, 17(1), 117; https://doi.org/10.3390/insects17010117
Submission received: 11 December 2025 / Revised: 18 January 2026 / Accepted: 19 January 2026 / Published: 20 January 2026
(This article belongs to the Section Insect Molecular Biology and Genomics)
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Simple Summary

In insects, the biogenic amine tyramine (TA) regulates various physiological and behavioral processes through tyramine receptors (TARs), which are G protein-coupled receptors (GPCRs). Insect TARs are classified into three groups: TAR1, TAR2, and TAR3, based on their structural, pharmacological, and biochemical properties. Among TARs, TAR1 has attracted much attention owing to its diverse functions and potential as a novel target. Here, we investigated the effects of targeting the type 1 tyramine receptor gene (LsTAR1) in the small brown planthopper Laodelphax striatellus, and found that knockdown of LsTAR1 inhibited the reproduction, feeding behavior, and survival of L. striatellus. These results deepen our understanding of the functions of insect TARs and provide the theoretical basis for the development of TARs as potential targets for insect pest control.

Abstract

Laodelphax striatellus is one of the most destructive rice pests. However, the functions of TARs in rice pests remain largely unknown. Here, we cloned LsTAR1 from L. striatellus. LsTAR1 shares considerable sequence identity with its orthologous receptors, and clusters closely with its corresponding receptor groups. LsTAR1 was most highly expressed in the egg stage and brain of L. striatellus. Knockdown of LsTAR1 by RNA interference (RNAi) prolonged the preoviposition and oviposition period, and reduced the fecundity. Furthermore, LsTAR1 knockdown significantly decreased the mRNA levels of vitellogenin (LsVg) in the fat body and ovary, and increased the transcript levels of Vg receptor (LsVgR) in the ovary, as well as altered the expression levels of genes related to juvenile hormone (JH) and 20-hydroxyecdysone (20E) pathway. Additionally, LsTAR1 knockdown markedly reduced the honeydew excretion of the adults and affected the expression of neuropeptide signaling genes involved in insect feeding. Notably, disruption of LsTAR1 signaling via RNAi or an antagonist reduced the survival rates of L. striatellus. This study uncovers the crucial roles of LsTAR1 in reproduction, feeding, and survival in L. striatellus, and highlights its potential as a promising target for developing novel pest management strategies.

Graphical Abstract

1. Introduction

Rice (Oryza sativa) is a staple food for more than half of the world’s population, and its production is frequently disrupted by various insect pests, such as the brown planthopper Nilaparvata lugens, white-backed planthopper Sogatella furcifera, and small brown planthopper Laodelphax striatellus, which not only harm rice plants by feeding on phloem sap and excreting honeydew but also compromise rice health by transmitting multiple plant viruses [1,2]. Currently, the control of rice planthoppers relies heavily on chemical insecticides, which has raised severe concerns about pest resurgence, biodiversity loss, and human health [3]. Therefore, there is an imperative to identify new pest management methodologies and new targets to reduce reliance on chemical insecticides. For this reason, understanding planthopper physiology and behavior is crucial for identifying pivotal molecular targets for the development of lead compounds or RNA interference (RNAi)-based insecticides to control these pests. In insects, the biogenic amines dopamine (DA), serotonin (5-HT), octopamine (OA), and tyramine (TA) play vital roles in controlling a wide variety of physiological and behavioral processes [4,5]. In L. striatellus, DA and OA are implicated in virus transmission, reproduction, and feeding behavior [6,7,8]. However, the roles of TA in L. striatellus have not been intensively studied.
TA was initially believed to be an intermediate product of OA, but now it is believed that TA itself functions as a neurotransmitter, neurohormone and neuromodulator. The physiological functions of TA and OA in invertebrates are similar to those of their vertebrate counterparts, adrenaline and noradrenaline [9,10]. In insects, TA mediates multiple physiological and behavioral processes, including locomotion [11], flight [12], reproduction [13], immunity [14], courtship [15], olfactory [16], gustatory [17], foraging [18], aggression [19], and feeding [20]. TA exerts its effects by signaling through TA receptors (TARs), which are G protein-coupled receptors (GPCRs). Insect TARs are divided into three types: TAR1, TAR2 and TAR3, based on their primary structure and the intracellular pathway activated [21,22]. TAR1 and TAR3 couple through both Gαq and Gαi, thus resulting in increased intracellular Ca2+ levels and reduced cAMP production. However, TAR3 has only been identified in Drosophila and other Dipteran insects [23]. TAR2 couples to both Gαq and Gαs, leading to the elevation of Ca2+ and cAMP levels [24].
Although numerous studies have investigated the functions of TARs, the majority have focused on model insects, such as D. melanogaster and Apis mellifera. In D. melanogaster, TAR1 was involved in gustatory response [25], locomotor activity [26], food intake [27], and lipid metabolism [28]. TAR2 participated in the modulation of courtship drive and renal function [15,29]. TAR3 controlled the choice between feeding and courtship [30]. In A. mellifera, TAR1 played an important role in the division of foraging labor [31], olfactory perception [32], gustatory responsiveness [17], reproductive physiology [33], and attention [34]. Other studies also reported that TAR1 regulated the olfactory response and the synthesis of vitellogenin (Vg) in Locusta migratoria [35,36], pheromone perception in Halyomorpha halys [37], mating and oviposition in Plutella xylostella [38], and Vg synthesis and release in Rhodnius prolixus [39]. Recently, our study has illustrated the role of TAR2 in reproduction and feeding in L. striatellus [40]. Additionally, TAR1 could be stimulated by a formamidine acaricide, amitraz, and its metabolite, as well as plant essential oil terpenoids, suggesting its potential as a biopesticide target [41,42,43]. The above studies on TARs indicated that TAR1 has attracted much attention owing to its diverse functions and potential as a novel target. However, the biological functions of TAR1 have yet to be examined in rice pests, including L. striatellus.
In this study, we cloned and characterized the type 1 TAR gene from L. striatellus, designated LsTAR1, and analyzed its spatial-temporal expression profiles. After RNAi knockdown of LsTAR1, we determined the reproductive parameters and the expression levels of LsVg/LsVgR and JH/20E-related genes. Furthermore, we investigated the feeding behavior by measuring the honeydew excretion and weight of adults after knocking down LsTAR1, and examined the expressions of genes related to feeding behavior. Finally, we calculated the survival rates of L. striatellus after injection with dsLsTAR1 or a TAR antagonist. Our study comprehensively elucidates the functions of LsTAR1, thereby providing the theoretical basis for developing TARs as potential targets for insect pest control.

2. Materials and Methods

2.1. Insect Rearing and cDNA Cloning

The original colonies of L. striatellus were obtained from rice fields in Yangzhou (Jiangsu, China), and maintained on Wuyujing 3 rice seedlings at 25 ± 1 °C, 70 ± 5% relative humidity, and a 14/10 h light/dark photoperiod [44,45].
The heads of L. striatellus were dissected into TRIzol (Invitrogen, Carlsbad, CA, USA) for RNA isolation. A total RNA of 1 μg was used for cDNA synthesis using HiScript®III 1st Strand cDNA Synthesis Kit (+gDNA wiper) (Vazyme, Nanjing, China). The fragments of putative LsTAR1 transcript were identified from L. striatellus head transcriptome data [46]. The full-length cDNA of LsTAR1 was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using the specific primers designed by Primer Premier 5.0 (Table S1), and cloned into the pCE2 TA/Blunt-Zero vector (Vazyme, Nanjing, China), and then verified by DNA sequencing.

2.2. Sequence Analysis

Amino acid sequences of TAR1 from N. lugens, Chilo suppressalis, P. xylostella, Tribolium castaneum, A. mellifera, and D. melanogaster were downloaded from the NCBI database, and they were aligned with the putative LsTAR1 sequence using ClustalX2 and GeneDoc. The transmembrane domains of LsTAR1 were predicted using the DeepTMHMM-1.0 (https://services.healthtech.dtu.dk/services/DeepTMHMM-1.0/ (accessed on 1 January 2025)). The potential phosphorylation sites by protein kinase C (PKC) and potential N-glycosylation sites were predicted with the NetPhos-3.1 Server (https://services.healthtech.dtu.dk/services/NetPhos-3.1/ (accessed on 1 January 2025)) and NetNGlyc-1.0 Server (https://services.healthtech.dtu.dk/services/NetNGlyc-1.0/ (accessed on 1 January 2025)), respectively. The phylogenetic tree was constructed with MEGA 11.0 using the neighbor-joining method [47], and visualized using the Interactive Tree of Life (iTOL) online tool [48].

2.3. Quantitative Real-Time PCR (qRT-PCR)

Samples were collected from eggs (n = 200), 1st to 5th instar nymphs (n = 30–100), 3-day-old female adults (n = 20), and male adults (n = 20). In addition, 3-day-old adults (n = 150) were dissected to obtain tissue samples, including antenna, wing, leg, cuticle, brain, midgut, fat body, hemolymph, Malpighian tubule, ovary, and male gonads. Total RNA from each sample was extracted for qRT-PCR, which was conducted on the Bio-Rad CFX 96™ Real-Time Detection System (Bio-Rad Laboratories Inc., Hercules, CA, USA) with a 20 μL reaction containing 10 μL ChamQ® SYBR qPCR Master Mix (Vazyme, Nanjing, China), 3 μL cDNA template, 1 μL each primer, and 5 μL ddH2O. Relative expression levels of the target genes were normalized against the levels of L. striatellus β-actin according to the 2−ΔΔCT method [49], and the primers for qRT-PCR are listed in Table S1.

2.4. RNAi

The DNA templates of GFP (green fluorescent protein) and LsTAR1 were amplified by RT-PCR using the primers with T7 promoter sequences (Table S1), and the PCR products (379 bp GFP and 280 bp LsTAR1) were used for synthesizing double-stranded GFP (dsGFP) and dsLsTAR1 with T7 RiboMAX™ Express RNAi System (Promega, Madison, WI, USA). A volume of 36 nL dsGFP or dsLsTAR1 (8 μg/μL) was injected into L. striatellus virgin adults (within 24 h) using Nanoject II Auto-Nanoliter Injector (Drummond Scientific, Broomall, PA, USA), and dsGFP treatment was used as a negative control. The injected adults were reared on fresh rice seedlings for 24 h, and then the injected virgin females and males were mated. RNAi efficiency of LsTAR1 was assessed at the 3rd and 5th day after dsRNA injection using qRT-PCR.

2.5. Reproduction Assay

The reproductive parameters of L. striatellus were measured as previously described [40]. A virgin female was injected with dsGFP or dsLsTAR1, and thereafter mated with a virgin male injected with dsGFP or dsLsTAR1. They were kept in a glass tube with fresh rice seedlings, and approximately 80 pairs were prepared per group. During the preoviposition period, the rice seedlings were replaced and dissected every day to observe egg laying. During the oviposition period, the seedlings were changed every 5 days, and the newly hatched nymphs on each seedling were counted every day until no new nymphs were found for 5 days. The number of unhatched eggs in each seedling was counted under a microscope and subsequently used to calculate the fecundity and hatching rate. Additionally, to determine the effects of TA on L. striatellus reproduction, different concentrations of TA (100 nM, 1 μM, and 10 μM) were injected into the virgin females or males, and then mated with the untreated virgin males or females, respectively. Every pair was maintained on the fresh rice seedlings in a glass tube for oviposition, with about 80 pairs for each group. The seedlings were replaced every 5 days, and the number of eggs laid in each seedling was counted. Furthermore, the females injected with dsGFP or dsLsTAR1 were dissected to collect the fat body and ovary to explore the expression changes in LsVg-, LsVgR-, and JH/20E-related genes

2.6. Feeding Assay

Planthopper honeydew excretion can be determined using the parafilm sachet technique [50]. Newly emerged L. striatellus adults were injected with dsGFP or dsLsTAR1 and fed on the fresh rice seedlings for 5 days. Thereafter, a parafilm sachet attached to the rice plant stems was used to confine the dsRNA-injected adults and collect their honeydew. After 48 h of feeding, the parafilm sachets were weighed before and after feeding to measure the accumulation of honeydew. One female individual or two male individuals were confined in a parafilm sachet as one replicate, and at least 15 replicates were performed for each treatment. For body weight analysis, newly emerged adults were injected with dsGFP or dsLsTAR1, and then raised on the fresh rice seedlings. After 5 days, three female individuals or three male individuals were weighed as one replicate, respectively, with at least 15 replicates for each treatment. Additionally, the adults (female–male ratio: 1:1) were collected for RNA extraction to investigate the mRNA levels of feeding-related neuropeptide signaling genes at the 3rd and 5th day after dsRNA injection.

2.7. Survival Assay

To measure the survival rates of L. striatellus, 3rd instar nymphs, 4th instar nymphs, 5th instar nymphs, and newly emerged adults were injected with 12 nL, 12 nL, 18 nL, and 36 nL of dsLsTAR1 or dsGFP, respectively, and allowed to recover on the fresh rice seedlings for 1 day before being used in the survival assay. The number of surviving L. striatellus individuals in each treatment was recorded every day until all individuals were dead, with fresh rice seedlings being changed every 5 days [51]. In addition, newly emerged adults were injected with 23 nL of yohimbine hydrochloride or phosphate-buffered saline (PBS) to perform a survival assay.

2.8. Statistical Analysis

Differences among multiple groups were analyzed with one-way ANOVA followed by Tukey’s honest significant difference test, and comparisons between two groups were performed using Student’s t-test. The survival curves were analyzed using the Kaplan–Meier method followed by the log-rank test. Data analyses and visualizations were performed using GraphPad Prism 9.4.1 (GraphPad Software, Boston, MA, USA).

3. Results

3.1. Cloning and Analysis of LsTAR1

According to transcriptome data of L. striatellus, we cloned full-length cDNA of LsTAR1 encoding 487 amino acids, and deposited it into GenBank (PV833295). The comparisons of amino acid sequences indicated that LsTAR1 shares the highest identity and similarity with NlTAR1 (93%, 96%), followed by TcTAR1 (55%, 69%), CsTAR1 (54%, 68%), PxTAR1 (53%, 68%), AmTAR1 (50%, 64%), and DmTAR1 (46%, 56%). Multiple sequence alignment showed that LsTAR1 possesses the typical features of GPCRs, including seven transmembrane domains (TM1-TM7), D3.49RY and N7.49PxxY motif. Several serine/threonine residues are predicted as the potential phosphorylation sites by PKC, and two potential N-glycosylation sites (N16 and N19) are located in the N-terminus. The residues (D3.32 in TM3, S5.42/5.46 in TM5) that are essential for ligand binding are well conserved in LsTAR1 (D136, S220/224) and other TAR1s, and the characteristic F6.44-X-X-C6.47-W6.48-X-P6.50-F6.51-F6.52 motif (F423VFCWLPFF in LsTAR1) is highly conserved in TM6 of various TAR1s (Figure 1).
To gain more information about LsTAR1, we further constructed the phylogenetic tree with other biogenic amine receptors. The phylogenetic analyses suggested that LsTAR1 clustered nicely with α2-adrenergic-like octopamine receptors (Octα2R), human α2-adrenergic receptors, and D2-like dopamine receptors (DOP3) (Figure 2).

3.2. Spatial-Temporal Expression Profiles of LsTAR1

The spatial-temporal expression patterns of LsTAR1 were determined by qRT-PCR (Figure 3). The results indicated that LsTAR1 was expressed across all the developmental stages of L. striatellus (eggs, 1st to 5th instar nymphs, female adults, and male adults). The transcript level of LsTAR1 was significantly higher in the eggs than in the nymphs and adults, and its expression in female and male adults was not significantly different (Figure 3A). Transcripts of LsTAR1 were widely expressed in different tissues of L. striatellus. Of all tissues, there was enrichment mostly in the brain, followed by the Malpighian tubule, male gonads, antenna, and ovary, and its expression levels showed no significant differences among the other tissues (Figure 3B). These expression patterns provide fundamental information concerning the potential roles of LsTAR1.

3.3. LsTAR1 Knockdown Leads to Reduced Reproduction Fitness

To explore the functions of LsTAR1 in L. striatellus, we silenced LsTAR1 by RNAi-mediated knockdown. qRT-PCR results revealed that the transcript levels of LsTAR1 were significantly reduced by 70.7% and 78.7% at the 3rd and 5th day after dsLsTAR1 injection, respectively (Figure 4A). Then, we performed the mating assay to determine the role of LsTAR1 in L. striatellus reproduction. dsRNA-injected L. striatellus were separated into four groups: dsGFP♀ × dsGFP♂, dsGFP♀ × dsLsTAR1♂, dsLsTAR1♀ × dsGFP♂, dsLsTAR1♀ × dsLsTAR1♂. The preoviposition period of the females from dsGFP♀ × dsLsTAR1♂, dsLsTAR1♀ × dsGFP♂, and dsLsTAR1♀ × dsLsTAR1♂ was significantly prolonged, compared with the control (dsGFP♀ × dsGFP♂) (Figure 4B). The oviposition period of the females from the dsLsTAR1♀ × dsGFP♂ group was significantly longer than that of the control (Figure 4C). Notably, the number of laid eggs varied depending on male mating partner: dsLsTAR1♀ × dsGFP♂ and dsLsTAR1♀ × dsLsTAR1♂ produced significantly fewer eggs, with 32.2% and 43.2% reduction observed, respectively, and the females in the dsGFP♀ × dsLsTAR1♂ group produced 20.2% fewer eggs (Figure 4D). The role of LsTAR1 in the egg hatching of L. striatellus was also investigated. The results indicated that no significant differences were observed in the egg-hatching period in four groups (Figure 4E), and the hatching rate in dsGFP♀ × dsLsTAR1♂, dsLsTAR1♀ × dsGFP♂, and dsLsTAR1♀ × dsLsTAR1♂ was slightly lower than that in the control (Figure 4F). To further determine the role of TA signaling in L. striatellus reproduction, we injected different concentrations of TA into female or male L. striatellus to count egg production. The results showed that the number of eggs laid by the females injected with 1 μM and 10 μM TA was increased by 22.5% and 50.9%, respectively (Figure 5A). Contrastingly, the number of eggs laid by the females mated with the males that were injected with different concentrations of TA was not significantly changed (Figure 5B). Taken together, these results clearly demonstrate that LsTAR1 exerts a significant impact on reproduction in females relative to males.

3.4. LsTAR1 Knockdown Impairs Vg Pathway

To gain mechanistic insight into the regulatory mechanism of LsTAR1 in female L. striatellus reproduction, the effects of LsTAR1 knockdown on the Vg pathway in the fat body and ovary were investigated using qRT-PCR (Figure 6). In the fat body, dsLsTAR1 injection led to 89.1% and 91.8% reduction in LsTAR1 mRNA levels at the 3rd and 5th day, respectively, suggesting that LsTAR1 was effectively silenced. At the 5th day after dsLsTAR1 injection, transcript level of LsVg decreased by 49.1% (Figure 6A). In the ovary, 84.2% and 83.6% knockdown efficiency of LsTAR1 was seen at the 3rd and 5th day after dsLsTAR1 injection, respectively. Knocking down LsTAR1 reduced LsVg mRNA abundance by 70.5% and 87.0%, but resulted in 57.6% and 53.4% increase in transcript abundance of LsVgR, which is an endocytic receptor involved in Vg uptake (Figure 6B). These results underscore a critical role of LsTAR1 in the regulation of the Vg pathway in L. striatellus.

3.5. LsTAR1 Knockdown Alters the Expression Levels of JH/20E-Related Genes

To further understand how LsTAR1 regulates the Vg pathway in female L. striatellus, the expression alterations of JH/20E-related genes were analyzed after LsTAR1 knockdown from the perspective of hormone regulation. Hence, we determined the mRNA levels of JH-related genes (LsMet, LsTai, LsJHAMT, LsKr-h1) and 20E-related genes (LsEcR, LsUSP, LsShadow, LsShade) in the fat body and ovary from female L. striatellus after dsLsTAR1 injection (Figure 7). In the fat body, the transcript levels of LsEcR and LsUSP decreased significantly at the 3rd and 5th day after dsLsTAR1 injection, while the transcripts of LsMet, LsTai, LsJHAMT, LsKr-h1, LsShadow, and LsShade decreased at the 5th day (Figure 7A). In the ovary, the transcript abundance of LsJHAMT and LsEcR increased significantly at the 3rd and 5th day after dsLsTAR1 injection. LsMet expression increased at the 3rd day, while LsTai, LsKr-h1, LsUSP, LsShadow, and LsShade expressions increased at the 5th day after injection (Figure 7B). Collectively, these data suggest that LsTAR1 knockdown affects the JH or 20E pathway in L. striatellus.

3.6. LsTAR1 Knockdown Disrupts Feeding Behavior

To test whether LsTAR1 is involved in modulating feeding behavior in L. striatellus, we examined the effects of LsTAR1 knockdown on the honeydew excretion and weight gain of L. striatellus adults. The results revealed that knockdown of LsTAR1 remarkably reduced the female and male adults’ honeydew excretion (Figure 8A,B). Additionally, knocking down LsTAR1 decreased the female adults’ weight (Figure 8C), but had no effect on the male adults’ weight (Figure 8D). To further elucidate the mechanism underlying LsTAR1 influences L. striatellus feeding behavior, we determined the expression changes in feeding-related neuropeptide signaling genes, such as LsAKH, LsAKHR, LsSK, LsSKR, LssNPF, LssNPFR, LsNPF, and LsNPFR [52]. The results showed that the mRNA levels of LsAKH and LsNPF increased markedly at both the 3rd and 5th day after dsLsTAR1 injection. LssNPFR expression was markedly upregulated at the 3rd day, while LsAKHR, LsSK, and LsSKR expressions were upregulated at the 5th day. The transcript levels of LssNPF and LsNPFR transitorily dropped at the 3rd day, thereafter increased at the 5th day after injection (Figure 8E). These observations together imply that LsTAR1 potentially modulates L. striatellus feeding behavior through the related neuropeptide signaling pathways.

3.7. Blockage of LsTAR1 Affects the Survival

To verify whether LsTAR1 affects the survival of L. striatellus, the survival rates of L. striatellus after injection with dsLsTAR1 or a TAR antagonist (yohimbine) were investigated (Figure 9). The results showed that dsLsTAR1 injection significantly reduced the survival of 3rd instar nymphs (χ2 = 8.947, df = 1, p = 0.0028), 4th instar nymphs (χ2 = 7.699, df = 1, p = 0.0055), and 5th instar nymphs (χ2 = 7.057, df = 1, p = 0.0079), compared with dsGFP injection (Figure 9A–C). No significant differences occurred in the survival rate of the adults after dsLsTAR1 injection (χ2 = 1.498, df = 1, p = 0.2209) (Figure 9D). Compared with PBS injection, the adult survival was not affected by 100 μM yohimbine injection (χ2 = 1.180, df = 1, p = 0.2773). After injection with 1 mM, the survival rate was remarkably reduced (χ2 = 11.11, df = 1, p = 0.0009) (Figure 9E). These results indicate that targeting LsTAR1 signaling exhibits inhibitory effects on L. striatellus survival.

4. Discussion

The functions of TA and TARs in physiology and behavior have been extensively studied in various insects [4,20,53]. However, the molecular characterization of TARs remains relatively limited in rice pests, and the functions of TAR1 have not yet been reported. L. striatellus is one of the economically important rice pests, and a deeper understanding of L. striatellus TARs will provide the fundamental knowledge to develop novel molecular targets for pest control. Herein, we cloned the type 1 TAR gene (LsTAR1) from L. striatellus and functionally characterized it.
The sequence alignment results showed that LsTAR1 has the typical characteristics of GPCRs and the conserved domains or motifs (Figure 1). The D3.32 residue (D136) and S5.42/5.46 residues (S220/224) play pivotal roles in the interaction with TA in the TAR1: D136 in TM3 forms an ion-pair with the protonated amino group of TA, and S220/224 in TM5 form hydrogen bonds with the p-hydroxyl group of TA [54]. The phylogenetic tree showed that TAR1 formed a sister group with Octα2R, human α2-adrenergic receptors, and DOP3 (Figure 2), which are well-supported by their similar pharmacological properties and highlight the concept of ‘ligand-hopping’ in the evolution of aminergic GPCRs [55,56,57].
Analysis of developmental expression profile suggested that LsTAR1 was expressed in all developmental stages, and had the highest transcript abundance in eggs, showing a decrease from egg to adult stage (Figure 3A). TAR1 has been observed to be significantly enriched in the egg stage in P. xylostella [58], H. halys [37], and Aedes aegypti [23], relative to other developmental stages. Similarly, TAR2 has also appeared to be highly expressed in the eggs of P. xylostella [58], A. aegypti [23], and L. striatellus [40]. These studies implied that TA signaling is critical for the development of early stages. Tissue-specific expression pattern of LsTAR1 revealed its highest mRNA level in the brain (Figure 3B), which correlated well with that found in various insects, such as C. suppressalis [59], D. melanogaster [60], A. mellifera [61], R. prolixus [62], and H. halys [37], therefore indicating a pivotal role of TAR1 in the neuromodulation of physiological functions and behaviors in insects. LsTAR1 expression in the Malpighian tubule was second only to that in the brain (Figure 3B). TAR1 has shown a relatively high transcript level in the Malpighian tubule of C. suppressalis [59] and D. melanogaster [60], and a recent study has demonstrated that TAR1 regulates the stellate cell activity of Malpighian tubule [63]. LsTAR1 was also expressed in the ovary and male gonads (Figure 3B), suggesting its involvement in reproductive processes. These results provide important clues to the possible roles of LsTAR1, which require further investigation.
TA is a crucial biogenic amine, and regulates the reproductive process in several insects, such as D. melanogaster [64], R. prolixus [65], P. xylostella [66], and A. mellifera [33]. TA exerts its physiological effects in reproduction through TARs, particularly TAR1 [33,38,39]. However, there is still a lack of comprehensive research on the function of TAR1 in insect reproduction. Here, our results revealed that the preoviposition period and oviposition period were prolonged, and the number of laid eggs and the hatching rate were reduced after dsLsTAR1 injection (Figure 4), suggesting the impaired reproductive fitness of L. striatellus after LsTAR1 knockdown. Similarly, the preoviposition period was extended, and the fecundity and hatchability were reduced in L. striatellus after LsTAR2 knockdown [40]. The dsGFP♀ × dsLsTAR1♂ group showed statistical differences in the preoviposition period, fecundity, and hatching rate, compared with the dsGFP♀ × dsGFP♂ group (Figure 4), indicating that male reproductive fitness may be affected. However, the degree of decline in fecundity in the dsLsTAR1♀ × dsGFP♂ group was greater than that in the dsGFP♀ × dsLsTAR1♂ group (p = 0.0292) (Figure 4). Meanwhile, we found that injecting TA into L. striatellus females could increase their egg production, while injecting TA into males would not affect the egg production of females that they mated with (Figure 5). These results together imply that LsTAR1 may play a more significant role in female reproduction than in male reproduction. In A. mellifera, TA feeding significantly increased the number of ovarioles [33]. In P. xylostella, the number of eggs laid by females injected with TA markedly increased [66]. Similarly, TAR1 knockout in P. xylostella females significantly reduced the yield of eggs, and TAR1 knockout males did not, and the shorter ovarioles and fewer mature oocytes occurred in the ovary of TAR1 knockout females [38]. In R. prolixus, the females injected with dsTAR1 laid significantly fewer eggs [39]. In L. migratoria, TAR1 knockdown arrested ovarian growth and oocyte maturation [36]. These collective findings provided evidence that downregulation of TAR1 negatively affected ovary development in females, therefore leading to reduced reproductive fitness. Thus, we conclude that LsTAR1 is essential for maintaining female L. striatellus reproduction.
For the successful reproduction of insect females, vitellogenesis is of central importance. During insect vitellogenesis, Vg is mainly synthesized in the fat body and subsequently taken up by the ovary through VgR-mediated endocytosis [67,68]. In planthoppers, the expression levels of Vg/VgR are strongly related to their reproductive capacity [69,70,71]. Thus, we investigated whether the reduced female L. striatellus reproduction caused by LsTAR1 knockdown correlated with LsVg/LsVgR expressions. Our results indicated that knocking down LsTAR1 significantly decreased the mRNA levels of LsVg in both the fat body and ovary, but increased LsVgR mRNA levels in the ovary (Figure 6). In A. mellifera, the Vg transcript level in the fat body was markedly reduced by TAR1 knockdown [33]. In L. migratoria, Vg mRNA level in the fat body was not affected by TAR1 knockdown, but Vg protein abundance in the fat body and ovary significantly declined [36]. Recently, a similar study has demonstrated that Vg mRNA abundance was reduced in the fat body and ovary of R. prolixus after TAR1 knockdown, whereas VgR showed an increase in the ovary [39], suggesting that upregulation of VgR potentially compensated for the impairment of Vg accumulation by regulating Vg uptake. Hence, we infer that LsTAR1 knockdown alters Vg/VgR expressions, which in turn can affect ovary development.
Insect vitellogenesis is controlled by two critical hormones, JH and 20E, which are responsible for Vg synthesis in the fat body and Vg uptake into the ovary [67,72]. The recent findings have demonstrated that biogenic amines can interact with hormone signaling pathways, thus affecting essential traits such as development, fertility, and reproduction [4]. In this study, we determined whether JH and 20E signaling pathways participated in LsTAR1 knockdown-mediated expression alterations of Vg/VgR in L. striatellus. We found that knocking down LsTAR1 significantly reduced the transcript levels of two JH receptor genes (LsMet and LsTai), a JH synthetic gene (LsJHAMT), and a JH early-response gene (LsKr-h1) in the fat body, as well as decreased the expressions of two ecdysone receptor genes (LsEcR and LsUSP) and two ecdysone synthetic genes (LsShadow and LsShade) (Figure 7A). Similarly, the expressions of JH pathway genes (Met, Tai, and Kr-h1) in the fat body were significantly impaired by TAR1 knockdown in R. prolixus [39]. In A. mellifera, the transcript levels of genes related to JH (JHE) and 20E (HR46 and ftz-f1) pathways in the fat body were significantly downregulated after TAR1 knockdown, and gene expression correlation analyses indicated that the regulatory process of Vg transcription by TAR1 involved JH and 20E pathways [33]. In contrast, knockdown of LsTAR1 significantly increased the mRNA levels of JH and 20E pathway genes in the ovary of L. striatellus (Figure 7B), which might correlate with the compensatory mechanisms in response to Vg uptake in the ovary. Another study reported that knockdown of the TA biosynthetic gene tyrosine decarboxylase 2 caused a sharp reduction in whole-body 20E concentration in D. melanogaster [73]. Taken together, LsTAR1 knockdown-mediated hormone signaling disorder potentially impairs the Vg pathway, consequently resulting in reproductive dysfunction.
Insect feeding is a complex and finely tuned behavior, which is regulated by the balance and interaction of biogenic amines and their receptors [20]. The involvement of TA and TARs in feeding behavior has been investigated in several insects. In Helicoverpa armigera, supplementation of TA enhanced the feeding rate and increased body weight [74]. In A. mellifera, TA modulated sucrose responsiveness via TAR1 [75]. In D. melanogaster, TAR neuron activation increased feeding in fed males [30], and TAR1 was required for food intake [27]. In general, honeydew excretion can be directly used for evaluating food intake in planthoppers, and the amount of food intake is directly proportional to the amount of honeydew excretion [76,77,78]. Here, we observed a marked reduction in honeydew excretion by L. striatellus females and males following dsLsTAR1 injection (Figure 8A,B). Similarly, knockdown of LsTAR2 and octopamine receptors (Octα1R and OctβRs) remarkably decreased the honeydew excretion in L. striatellus [7,8,40]. Additionally, the weight gain is also an indicator of feeding activity in planthoppers [79]. The weight of L. striatellus females was reduced by LsTAR1 knockdown, whereas the weight of males was not changed (Figure 8C,D). Similarly, LsTAR2 knockdown reduced the weight of L. striatellus females, but not males [40], indicating that the weight of insects may not be solely affected by feeding. The gene network for regulating insect feeding behavior is complicated, in which the neuropeptide signaling pathways involve [52]. Thus, the expressions of neuropeptide signaling genes related to feeding in L. striatellus were determined after knocking down LsTAR1. We found that dsLsTAR1 injection altered mRNA levels of the neuropeptide genes LsAKH, LsSK, LssNPF, LsNPF, and their receptor genes (Figure 8E). In H. armigera, TA treatment increased transcript abundance of a satiating factor, SK, and a feeding-inducing factor, NPFR [74]. In A. mellifera, knockdown of TAR1 did not affect AKH expression, but significantly reduced AKHR expression [33]. In N. lugens, the biogenic amine DA regulated the expression of sNPF and sNPFR to mediate the feeding behavior [79]. Collectively, we speculate that LsTAR1 knockdown may lead to the dysregulation of feeding-related neuropeptide signaling pathways, thus adversely affecting the feeding behavior of L. striatellus.
Reproduction and feeding are crucial factors in insect pest outbreaks, and involve various related genes that can serve as the targets [52,80]. Our study has demonstrated that RNAi-mediated LsTAR1 knockdown significantly impaired the reproductive capacity and feeding behavior of L. striatellus, suggesting its potential as a target for pest control. Here, we further evaluated the effects of LsTAR1 knockdown on the survival of L. striatellus and found that dsLsTAR1 treatment markedly reduced the survival rates of 3rd–5th instar nymphs but did not affect the survival rates of adults (Figure 9A–D). In future research, combining nanocarriers or exogenous stabilizers may improve the application efficiency of dsLsTAR1. RNAi is an effective pest management strategy through silencing the crucial genes in target organisms; thus, identifying the optimal target genes is critical for harnessing RNAi technology for sustainable pest control [80,81]. The future developments in nanoparticle-based delivery systems, the application of transgenic approaches, and multi-targeting technologies will enhance the feasibility of using RNAi [81,82]. Yohimbine is an antagonist showing high affinity for TAR1 [53]. Our results indicated that yohimbine injection significantly inhibited the survival of L. striatellus adults (Figure 9E). A similar study reported that disruption of TA signaling by injecting antagonists exhibited inhibitory effects on the reproduction and survival of Anopheles gambiae [83]. These results together suggest that targeting TAR1 can be an effective strategy for managing rice planthoppers.

5. Conclusions

In conclusion, this study revealed molecular characteristics and expression patterns of LsTAR1 in L. striatellus. Knocking down LsTAR1 impaired female L. striatellus reproduction, which may be caused by JH/20E dysregulation-mediated Vg pathway dysfunction. Additionally, LsTAR1 knockdown markedly reduced L. striatellus adults’ honeydew excretion, possibly due to the disruption of feeding-related neuropeptide signaling pathways. Furthermore, targeting LsTAR1 via dsRNA or the antagonist yohimbine inhibited the survival of L. striatellus. Overall, our findings demonstrate the essential roles of TAR1 in insect reproduction, feeding, and survival, not only advancing our knowledge of TAR regulation of physiological and behavioral processes in insects, but also offering a potential target for pest control via designing RNAi insecticides or small molecules.

Supplementary Materials

The following supporting information can be downloaded at https://www.mdpi.com/article/10.3390/insects17010117/s1, Table S1: The primers used in this study; Table S2: The accession numbers of the sequences used in this study.

Author Contributions

Conceptualization, G.X.; methodology, G.X.; formal analysis, Z.Y. and L.F.; investigation, Z.Y., L.F., Y.C., K.Y., Y.Z., L.W., R.Q., and M.Q.; data curation, Z.Y. and L.F.; writing—original draft preparation, G.X.; writing—review and editing, G.X.; visualization, Z.Y., L.F., and G.X.; supervision, G.Y.; project administration, G.X.; funding acquisition, G.Y. and G.X. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the National Natural Science Foundation of China (32572804, 32302344) and the National Key Research and Development Program of China (2024YFE0103400).

Data Availability Statement

The original contributions presented in this study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 1. Multiple sequence alignment of LsTAR1 and its orthologous receptors from Nilaparvata lugens (NlTAR1), Chilo suppressalis (CsTAR1), Plutella xylostella (PxTAR1), Tribolium castaneum (TcTAR1), Apis mellifera (AmTAR1), and Drosophila melanogaster (DmTAR1). Putative seven transmembrane domains (TM1-TM7), D3.49RY motif, and N7.49PxxY motif are indicated by black lines. Potential N-glycosylation sites and potential phosphorylation sites by PKC are marked with empty triangles and filled triangles, respectively. Amino acid residues that are predicted to function in ligand binding are indicated by empty diamonds. Two conserved cysteine residues that form a disulfide bond are labeled by diamonds. The second phenylalanine (F431) after the FxxxWxP motif in TM6, which is a unique feature of aminergic GPCRs, is marked with a filled circle. The accession numbers of amino acid sequences used in this alignment are provided in Table S2.
Figure 1. Multiple sequence alignment of LsTAR1 and its orthologous receptors from Nilaparvata lugens (NlTAR1), Chilo suppressalis (CsTAR1), Plutella xylostella (PxTAR1), Tribolium castaneum (TcTAR1), Apis mellifera (AmTAR1), and Drosophila melanogaster (DmTAR1). Putative seven transmembrane domains (TM1-TM7), D3.49RY motif, and N7.49PxxY motif are indicated by black lines. Potential N-glycosylation sites and potential phosphorylation sites by PKC are marked with empty triangles and filled triangles, respectively. Amino acid residues that are predicted to function in ligand binding are indicated by empty diamonds. Two conserved cysteine residues that form a disulfide bond are labeled by diamonds. The second phenylalanine (F431) after the FxxxWxP motif in TM6, which is a unique feature of aminergic GPCRs, is marked with a filled circle. The accession numbers of amino acid sequences used in this alignment are provided in Table S2.
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Figure 2. Phylogenetic analyses of LsTAR1 and various biogenic amine receptors. Drosophila ninaE rhodopsin 1 (DmninaE) and FMRFamide receptor (DmFR) were used as outgroups. LsTAR1 is in bold, and the accession numbers of the used amino acid sequences are provided in Table S2. Abbreviations: Aa, Aedes aegypti; Ag, Anopheles gambiae; Am, Apis mellifera; Bm, Bombyx mori; Cs, Chilo suppressalis; Dm, Drosophila melanogaster; Ls, Laodelphax striatellus; Nl, Nilaparvata lugens; Px, Plutella xylostella; Tc, Tribolium castaneum; Hs, Homo sapiens.
Figure 2. Phylogenetic analyses of LsTAR1 and various biogenic amine receptors. Drosophila ninaE rhodopsin 1 (DmninaE) and FMRFamide receptor (DmFR) were used as outgroups. LsTAR1 is in bold, and the accession numbers of the used amino acid sequences are provided in Table S2. Abbreviations: Aa, Aedes aegypti; Ag, Anopheles gambiae; Am, Apis mellifera; Bm, Bombyx mori; Cs, Chilo suppressalis; Dm, Drosophila melanogaster; Ls, Laodelphax striatellus; Nl, Nilaparvata lugens; Px, Plutella xylostella; Tc, Tribolium castaneum; Hs, Homo sapiens.
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Figure 3. Expression profiles of LsTAR1 in L. striatellus. (A) Temporal expression levels of LsTAR1 at different stages. N1–N5, 1st–5th instar nymph. (B) Spatial expression levels of LsTAR1 in various tissues. Lowercase letters above the bars indicate statistically significant differences (p < 0.05). Data are shown as mean values ± SEM (n = 3).
Figure 3. Expression profiles of LsTAR1 in L. striatellus. (A) Temporal expression levels of LsTAR1 at different stages. N1–N5, 1st–5th instar nymph. (B) Spatial expression levels of LsTAR1 in various tissues. Lowercase letters above the bars indicate statistically significant differences (p < 0.05). Data are shown as mean values ± SEM (n = 3).
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Figure 4. The effects of LsTAR1 knockdown on L. striatellus reproduction. (A) The silencing efficiencies of LsTAR1 in L. striatellus (n = 3). (B) The preoviposition period of the females from different mating patterns (n = 32–38). (C) The oviposition period of the females from different mating patterns (n = 30–38). (D) The number of eggs laid by the females from different mating patterns (n = 31–36). (E) The hatching period of eggs laid by the females from different mating patterns (n = 24–25). (F) The hatching rate of eggs laid by the females from different mating patterns (n = 31–38). Two-tailed unpaired Student’s t-test was used for comparison (* p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM.
Figure 4. The effects of LsTAR1 knockdown on L. striatellus reproduction. (A) The silencing efficiencies of LsTAR1 in L. striatellus (n = 3). (B) The preoviposition period of the females from different mating patterns (n = 32–38). (C) The oviposition period of the females from different mating patterns (n = 30–38). (D) The number of eggs laid by the females from different mating patterns (n = 31–36). (E) The hatching period of eggs laid by the females from different mating patterns (n = 24–25). (F) The hatching rate of eggs laid by the females from different mating patterns (n = 31–38). Two-tailed unpaired Student’s t-test was used for comparison (* p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM.
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Figure 5. The effects of TA injection on the number of eggs laid by L. striatellus. (A) The effects of injecting different concentrations of TA into L. striatellus females on the number of eggs laid (n = 30–38). (B) The effects of injecting different concentrations of TA into L. striatellus males on the number of eggs laid by the females that were mated with (n = 32–37). Two-tailed unpaired Student’s t test was used for comparison (*** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM.
Figure 5. The effects of TA injection on the number of eggs laid by L. striatellus. (A) The effects of injecting different concentrations of TA into L. striatellus females on the number of eggs laid (n = 30–38). (B) The effects of injecting different concentrations of TA into L. striatellus males on the number of eggs laid by the females that were mated with (n = 32–37). Two-tailed unpaired Student’s t test was used for comparison (*** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM.
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Figure 6. The effects of LsTAR1 knockdown on LsVg/LsVgR expressions in the fat body (A) and ovary (B) of L. striatellus females at the 3rd and 5th day after injection. Two-tailed unpaired Student’s t-test was used for comparison (** p < 0.01; *** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM (n = 3).
Figure 6. The effects of LsTAR1 knockdown on LsVg/LsVgR expressions in the fat body (A) and ovary (B) of L. striatellus females at the 3rd and 5th day after injection. Two-tailed unpaired Student’s t-test was used for comparison (** p < 0.01; *** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM (n = 3).
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Figure 7. The effects of LsTAR1 knockdown on the expressions of JH/20E-related genes in the fat body (A) and ovary (B) of L. striatellus females at the 3rd and 5th day after injection. Two-tailed unpaired Student’s t-test was used for comparison (* p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM (n = 3). Abbreviations: LsMet, methoprene-tolerant; LsTai, taiman; LsJHAMT, juvenile hormone acid methyltransferase; LsKr-h1, Krüppel homolog1; LsEcR, ecdysone receptor; LsUSP, ultraspiracle protein; LsShadow, Shadow; LsShade, Shade.
Figure 7. The effects of LsTAR1 knockdown on the expressions of JH/20E-related genes in the fat body (A) and ovary (B) of L. striatellus females at the 3rd and 5th day after injection. Two-tailed unpaired Student’s t-test was used for comparison (* p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM (n = 3). Abbreviations: LsMet, methoprene-tolerant; LsTai, taiman; LsJHAMT, juvenile hormone acid methyltransferase; LsKr-h1, Krüppel homolog1; LsEcR, ecdysone receptor; LsUSP, ultraspiracle protein; LsShadow, Shadow; LsShade, Shade.
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Figure 8. The effects of LsTAR1 knockdown on feeding behavior and the expressions of feeding-related neuropeptide signaling genes in L. striatellus. (A,B) The honeydew excretion of female and male adults after dsLsTAR1 injection (n = 19–31). (C,D) The weight of female and male adults after dsLsTAR1 injection (n = 17–23). (E) Relative expression levels of feeding-related neuropeptide signaling genes at the 3rd and 5th day after dsLsTAR1 injection (n = 3). Two-tailed unpaired Student’s t-test was used for comparison (* p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM. Abbreviations: LsAKH, adipokinetic hormone; LsAKHR, adipokinetic hormone receptor; LsSK, sulfakinin; LsSKR, sulfakinin receptor; LssNPF, short neuropeptide F; LssNPFR, short neuropeptide F receptor; LsNPF, neuropeptide F; LsNPFR, neuropeptide F receptor.
Figure 8. The effects of LsTAR1 knockdown on feeding behavior and the expressions of feeding-related neuropeptide signaling genes in L. striatellus. (A,B) The honeydew excretion of female and male adults after dsLsTAR1 injection (n = 19–31). (C,D) The weight of female and male adults after dsLsTAR1 injection (n = 17–23). (E) Relative expression levels of feeding-related neuropeptide signaling genes at the 3rd and 5th day after dsLsTAR1 injection (n = 3). Two-tailed unpaired Student’s t-test was used for comparison (* p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001; ns, not significant). Data are shown as mean values ± SEM. Abbreviations: LsAKH, adipokinetic hormone; LsAKHR, adipokinetic hormone receptor; LsSK, sulfakinin; LsSKR, sulfakinin receptor; LssNPF, short neuropeptide F; LssNPFR, short neuropeptide F receptor; LsNPF, neuropeptide F; LsNPFR, neuropeptide F receptor.
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Figure 9. Survival rate of L. striatellus after blockage of LsTAR1. (A) Kaplan–Meier survival curve of 3rd instar nymphs of L. striatellus after dsLsTAR1 injection (n = 113–120). (B) Kaplan–Meier survival curve of 4th instar nymphs of L. striatellus after dsLsTAR1 injection (n = 73–89). (C) Kaplan–Meier survival curve of 5th instar nymphs of L. striatellus after dsLsTAR1 injection (n = 97–98). (D) Kaplan–Meier survival curve of L. striatellus adults after dsLsTAR1 injection (n = 92–101). (E) Kaplan–Meier survival curve of L. striatellus adults after injection with different concentrations of yohimbine (n = 92–98).
Figure 9. Survival rate of L. striatellus after blockage of LsTAR1. (A) Kaplan–Meier survival curve of 3rd instar nymphs of L. striatellus after dsLsTAR1 injection (n = 113–120). (B) Kaplan–Meier survival curve of 4th instar nymphs of L. striatellus after dsLsTAR1 injection (n = 73–89). (C) Kaplan–Meier survival curve of 5th instar nymphs of L. striatellus after dsLsTAR1 injection (n = 97–98). (D) Kaplan–Meier survival curve of L. striatellus adults after dsLsTAR1 injection (n = 92–101). (E) Kaplan–Meier survival curve of L. striatellus adults after injection with different concentrations of yohimbine (n = 92–98).
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MDPI and ACS Style

Yan, Z.; Fu, L.; Chen, Y.; Ye, K.; Zhang, Y.; Wu, L.; Qian, R.; Qian, M.; Yang, G.; Xu, G. Targeting the Type 1 Tyramine Receptor LsTAR1 Inhibits Reproduction, Feeding and Survival in the Small Brown Planthopper Laodelphax striatellus. Insects 2026, 17, 117. https://doi.org/10.3390/insects17010117

AMA Style

Yan Z, Fu L, Chen Y, Ye K, Zhang Y, Wu L, Qian R, Qian M, Yang G, Xu G. Targeting the Type 1 Tyramine Receptor LsTAR1 Inhibits Reproduction, Feeding and Survival in the Small Brown Planthopper Laodelphax striatellus. Insects. 2026; 17(1):117. https://doi.org/10.3390/insects17010117

Chicago/Turabian Style

Yan, Zihan, Liran Fu, Yutong Chen, Kangjing Ye, Yuanyuan Zhang, Liang Wu, Ruhao Qian, Mingshi Qian, Guoqing Yang, and Gang Xu. 2026. "Targeting the Type 1 Tyramine Receptor LsTAR1 Inhibits Reproduction, Feeding and Survival in the Small Brown Planthopper Laodelphax striatellus" Insects 17, no. 1: 117. https://doi.org/10.3390/insects17010117

APA Style

Yan, Z., Fu, L., Chen, Y., Ye, K., Zhang, Y., Wu, L., Qian, R., Qian, M., Yang, G., & Xu, G. (2026). Targeting the Type 1 Tyramine Receptor LsTAR1 Inhibits Reproduction, Feeding and Survival in the Small Brown Planthopper Laodelphax striatellus. Insects, 17(1), 117. https://doi.org/10.3390/insects17010117

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