Disruption of kynurenine pathway reveals physiological importance of tryptophan catabolism in Henosepilachna vigintioctopunctata

RNAi-Mediated Functional Analysis Reveals the Regulation of Oocyte Vitellogenesis by Ecdysone Signaling in Two Coleoptera Species

Coleoptera is the largest taxa of animals by far. The robust reproductive capacity is one of the main reasons for such domination. Successful female reproduction partially relies on effective vitellogenesis. However, the hormone regulation of vitellogenesis remains to be explored. In the present paper, in vitro culture of Leptinotarsa decemlineata 1-day-old adult fat bodies in the 20E-contained median did not activate juvenile hormone production and insulin-like peptide pathways, but significantly stimulated the expression of two LdVg genes, in a cycloheximide-dependent pattern. In vivo RNA interference (RNAi) of either ecdysone receptor (LdEcR) or ultraspiracle (Ldusp) by injection of corresponding dsRNA into 1-day-old female adults inhibited oocyte development, dramatically repressed the transcription of LdVg genes in fat bodies and of LdVgR in ovaries; application of JH into the LdEcR or Ldusp RNAi L. decemlineata females did not restore the oocyte development, partially rescued the decreased LdVg mRNA levels but over-compensated LdVgR expression levels. The same RNAi experiments were performed in another Coleoptera species, Henosepilachna vigintioctopunctata. Little yolk substances were seen in the misshapen oocytes in the HvEcR or Hvusp RNAi ovaries, in contrast to larger amounts of yolk granules in the normal oocytes. Correspondingly, the transcript levels of HvVg in the fat bodies and ovaries decreased significantly in the HvEcR and Hvusp RNAi samples. Our results here show that 20E signaling is indispensable in the activation of vitellogenesis in the developing oocytes of the two beetle species.

Dusky-like Is Critical for Morphogenesis of the Cellular Protuberances and Formation of the Cuticle in Henosepilachna vigintioctopunctata

Dusky-like (Dyl) is a transmembrane protein containing a zona pellucida domain. Its physiological roles during metamorphosis have been well explored in Drosophila melanogaster and have also been documented in Tribolium castaneum. However, Dyl has undergone a functional shift between Diptera and Coleoptera insects. Further investigation of Dyl in other insects will be helpful to further clarify its function in insect growth and development. Henosepilachna vigintioctopunctata is an important Coleoptera that causes enormous economic losses in agriculture in China. In this study, we found that the expression of Hvdyl was detectable in embryos, larvae, prepupae, pupae, and adults. We knocked down Hvdyl in third- and fourth-instar larvae and pupae with RNA interference (RNAi). RNAi of Hvdyl mainly caused two phenotypic defects. Firstly, the growth of epidermal cellular protuberances was suppressed. Injection of dsdyl (double-stranded dusky-like RNA) at the third-instar larval stage truncated the scoli throughout the thorax and abdomen and shortened the setae on the head capsules and mouthparts of the fourth-instar larvae. Introduction of dsdyl at the third- and fourth-instar stages led to misshapen pupal setae. The setae were shortened or became black nodules. Treatment with dsdyl at the larval and pupal stages resulted in deformed adults with completely suppressed wing hairs. Moreover, the knockdown of Hvdyl at the third-instar stage caused deformed larval mouthparts at the fourth-instar period. As a result, foliage consumption was inhibited, and larval growth was slowed. The results indicate that Dyl is associated with the growth of cellular protuberances throughout development and with the formation of the cuticle in H. vigintioctopunctata.

Vermilion and cinnabar are involved in ommochrome pigment biosynthesis in eyes but not wings of Bicyclus anynana butterflies

If the same pigment is found in different tissues in a body, it is natural to assume that the same metabolic pathways are deployed similarly in each tissue. Here we show that this is not the case for ommochromes, the red and orange pigments found in the eyes and wings of butterflies. We tested the expression and function of vermilion and cinnabar, two known fly genes in the ommochrome pathway, in the development of pigments in the eyes and in the wings of Bicyclus anynana butterflies, both traits having reddish/orange pigments. By using fluorescent in-situ hybridization (HCR3.0) we localized the expression of vermilion and cinnabar in the cytoplasm of pigment cells in the ommatidia but observed no clear expression for either gene on larval and pupal wings. We then disrupted the function of both genes, using CRISPR-Cas9, which resulted in the loss of pigment in the eyes but not in the wings. Using thin-layer chromatography and UV-vis spectroscopy we identified the presence of ommochrome and ommochrome precursors in the orange wing scales and in the hemolymph of pupae. We conclude that the wings either synthesize ommochromes locally, with yet unidentified enzymes or incorporate these pigments synthesized elsewhere from the hemolymph. Different metabolic pathways or transport mechanisms, thus, lead to the presence of ommochromes in the wings and eyes of B. anynana butterflies.

Disruption of tetrahydrobiopterin (BH4) biosynthesis pathway affects cuticle pigmentation in Henosepilachna vigintioctopunctata

Tetrahydrobiopterin (BH4) is produced from guanosine triphosphate (GTP) under catalyzation of GTP cyclohydrolase I (GTPCH), 6-pyruvoyltetrahydropterin synthase (PTPS) and sepiapterin reductase (SR), among others. In Drosophila melanogaster, BH4 and other pteridines are required for cuticle tanning and eye pigmentation. In this study, two Hvgtpch (Hvgtpch-a and Hvgtpch-b), an Hvptps and an Hvsr transcripts were identified in a serious defoliator Henosepilachna vigintioctopunctata. Hvgtpch-a and Hvgtpch-b were highly expressed just before and/or right after the molt, in contrast to Hvptps and Hvsr. RNA interference (RNAi) by injection of a dsgtpch targeting the common fragment of Hvgtpch-a and Hvgtpch-b into the third instar larvae caused albino fourth-instar larvae and pupae. Around 80% of the Hvgtpch RNAi larvae failed to pupate. The remaining 20% of Hvgtpch RNAi pupated beetles did not completely remove the larval/pupal exuviae after emerged as adults and eventually died. Depletion of Hvgtpch at the fourth instar stage resulted in under-pigmented pupae and adults, with significantly low pupation and emergence rates. The Hvgtpch RNAi adults rarely moved and fed on plant leaves; they died within a week after emergence. Silence of Hvptps or Hvsr at the third- and fourth-instar stages led to similar but less serious phenotypes, with lowest influence in the Hvsr RNAi ladybirds. Moreover, RNAi of Hvgtpch, Hvptps or Hvsr did not affect coloration of the larval ocelli and pupal/adult compound eyes. Therefore, our results demonstrated that pteridines are involved in melanin formation but not in eye pigmentation in H. vigintioctopunctata. Moreover, our findings will enable the development of a dsgtpch-based pesticide to control H. vigintioctopunctata larvae.

Requirement of Myoglianin for metamorphosis in the beetle Henosepilachna vigintioctopunctata

Henosepilachna vigintioctopunctata is a serious defoliating beetle attacking Solanaceae and Cucurbitaceae plants in many Asian countries. In the present paper, we identified a putative myoglianin (myo) gene. Hvmyo was actively transcribed throughout development, from embryo to adult. RNA interference (RNAi)-aided knockdown of Hvmyo delayed larval development by more than 2 days, reduced larval body size, inhibited the growth of antennae, wings and legs and disturbed gut purge. Knockdown of Hvmyo impaired the larval-pupal transition. All the Hvmyo RNAi larvae arrested at the larval stage or formed misshapen pupae or adults. The deformed pupae and adults were partially wrapped with exuviae, bearing separated wings. Moreover, the expression levels of five ecdysteroidogenesis genes (Hvspo, Hvphm, Hvdib, Hvsad and Hvshd), a prothocicotropic hormone (PTTH)/Torso pathway gene (Hvtorso), two 20E receptor genes (HvEcR and HvUSP), and two 20E signalling genes (HvE93 and HvFTZ-F1) were as a result of HvMyo RNAi significantly lowered. Conversely, the expression of a JH biosynthesis gene (Hvjhamt), a JH receptor gene HvMet and a JH signalling gene HvKr-h1 was greatly enhanced. Although ingestion of 20E and Hal rescued the 20E signal, it could not alleviate larval performance and defective phenotypes. Our results suggest that Myo exerts four distinctive roles in ecdysteroidogenesis, JH production, organ growth and larva-pupa-adult transformation in H. vigintioctopunctata.

Knockdown of Ecdysone-Induced Protein 93F Causes Abnormal Pupae and Adults in the Eggplant Lady Beetle

Ecdysone-induced protein 93F (E93) plays triple roles during post-embryonic development in insects whose juvenile instars are more than four. However, it only acts as a specifier of adult structures in Drosophila flies whose larval instars are fixed at three. In this study, we determined the functions of E93 in the eggplant lady beetle (Henosepilachna vigintioctopunctata), which has four larval instars. We uncovered that E93 was abundantly expressed at the prepupal and pupal stages. A precocious inhibition of the juvenile hormone signal by RNA interference (RNAi) of HvKr-h1 or HvHairy, two vital downstream developmental effectors, at the penultimate instar larval stage increased the expression of E93, Conversely, ingestion of JH by the third-instar larvae stimulated the expression of HvKr-h1 but repressed the transcription of either HvE93X1 or HvE93X2. However, disturbance of the JH signal neither drove premature metamorphosis nor caused supernumerary instars. In contrast, depletion of E93 at the third- and fourth-instar larval and prepupal stages severely impaired pupation and caused a larval-pupal mixed phenotype: pupal spines and larval scoli were simultaneously presented on the cuticle. RNAi of E93 at the pupal stage affected adult eclosion. When the beetles had suffered from a dsE93 injection at the fourth-instar larval and pupal stages, a few resultant adults emerged, with separated elytra, abnormally folded hindwings, a small body size and short appendages. Taken together, our results suggest the larval instars are fixed in H. vigintioctopunctata; E93 serves as a repressor of larval characters and a specifier of adult structures during the larval–pupal–adult transition.

Silencing tyrosine hydroxylase or dopa decarboxylase gene disrupts cuticle tanning during larva-pupa-adult transformation in Henosepilachna vigintioctopunctata

BACKGROUND

The 28-spotted potato ladybird, Henosepilachna vigintioctopunctata, is a notorious defoliator of many solanaceous and cucurbitaceous plants. Tyrosine hydroxylase (TH) and dopa decarboxylase (DDC) are responsible for cuticle tanning pathway in insects.

RESULTS

We identified HvTH and HvDDC in H. vigintioctopunctata, and found that high levels of them were accumulated just before or right after molting. Injection of dsHvTH or feeding 3-iodo-tyrosine (3-IT) at the third instar larval stage repressed tanning of the larval cuticle, reduced larval feeding, inhibited larval growth, and consequently caused 100% of larval mortality. Knockdown of HvDDC at the third instar larval stage hardly affected the coloration of larval head, and partially inhibited pigmentation of larval bodies and around 80% of the HvDDC RNAi larvae developed into albino pupae and adults. Moreover, depletion of HvTH or HvDDC at the fourth instar larval stage resulted in albino pupae and adults. The HvTH or HvDDC hypomorph adults fully or partially failed to remove the larval/pupal exuviae, possessed pale and abnormal wings, and poorly tanned heads and bodies, and eventually, struggled for several days without feeding on leaves before death.

CONCLUSION

These results show that TH and DDC play key roles in larval and adult cuticle tanning and development in H. vigintioctopunctata. Also, these findings suggest that dopa- and dopamine-originated pigments are essential for larval and adult feeding behavior and the molting process during emergence. © 2022 Society of Chemical Industry.

Metabolite Changes in Orange Dead Leaf Butterfly Kallima inachus during Ontogeny and Diapause

Holometabolism is a form of insect development which includes four life stages: egg, larva, pupa, and imago (or adult). The developmental change of whole body in metabolite levels of holometabolous insects are usually ignored and lack study. Diapause is an alternative life-history strategy that can occur during the egg, larval, pupal, and adult stages in holometabolous insects. Kallima inachus (Lepidoptera: Nymphalidae) is a holometabolous and adult diapausing butterfly. This study was intended to analyze metabolic changes in K. inachus during ontogeny and diapause through a non-targeted UPLC-MS/MS (ultra-performance liquid chromatograph coupled with tandem mass spectrometry) based metabolomics analysis. A variety of glycerophospholipids (11), amino acid and its derivatives (16), and fatty acyls (nine) are crucial to the stage development of K. inachus. 2-Keto-6-acetamidocaproate, N-phenylacetylglycine, Cinnabarinic acid, 2-(Formylamino) benzoic acid, L-histidine, L-glutamate, and L-glutamine play a potentially important role in transition of successive stages (larva to pupa and pupa to adult). We observed adjustments associated with active metabolism, including an accumulation of glycerophospholipids and carbohydrates and a degradation of lipids, as well as amino acid and its derivatives shifts, suggesting significantly changed in energy utilization and management when entering into adult diapause. Alpha-linolenic acid metabolism and ferroptosis were first found to be associated with diapause in adults through pathway analyses. Our study lays the foundation for a systematic study of the developmental mechanism of holometabolous insects and metabolic basis of adult diapause in butterflies.

Is there any biological insight (or respite) for insects exposed to plastics? Measuring the impact on an insects central carbon metabolism when exposed to a plastic feed substrate

Insects used to treat organic waste streams and produce valuable protein products are increasingly exposed to plastic contaminated source material assimilating plastic carbon into organic biomass, which is pervasive and hazardous to organisms. Our understanding of this increased insect-plastic interaction remains limited and needs urgent scientific attention if plastic biodegradation and production rates of quality protein are to be improved. Herein, we investigated the biochemical impact of various plastics using three insect models. Black Soldier Fly (BSF), Mealworm (MW), and Wax Moth (WM) larva were each exposed to a plastic substrate (PET, PE, PS, Expanded PE, PP, and PLA) as the primary carbon source for five days to explore any positive metabolic benefits in terms of insect performance and plastic degradation potential. Central carbon metabolism (CCM) metabolites were analyzed via a targeted tMRM liquid chromatography triple quadrupole mass spectrometry (LC-QqQ-MS) method. Unique expressed pathways were observed for each insect model. When reared on PET, BSF larvae were found to have an elevated pyrimidine metabolism, while the purine metabolism pathway was strongly expressed on other plastics. BSF also exhibited a downregulated Vitamin B6 metabolism across all plastics, indicating a likely gut-symbiont breakdown. The MW and WM model insects were metabolically more active on PLA and expanded foam plastics. Further, WM exhibited an elevation in Vitamin B6 metabolism. This data suggests a positive insect-specific interaction towards certain plastic types that warrants further investigation. It is anticipated that through deeper insight into the metabolic impact and benefits afforded from certain plastics, an insect biotransformation pipeline can be established that links fit-for-purpose insect models to individual plastic types that address our growing plastic waste issue.

Probiotic potentials of the silkworm gut symbiont Enterococcus casseliflavus ECB140, a promising L-tryptophan producer living inside the host

AIMS

L-tryptophan is an essential aromatic amino acid for the growth and development of animals. Studies about enteric L-tryptophan-producing bacteria are scarce. In this report, we characterized the probiotic potential of Enterococcus casseliflavus ECB140, focusing on its L-tryptophan production abilities.

METHODS AND RESULTS

ECB140 strain was isolated from the silkworm gut and can survive under strong alkaline environmental conditions. Bacterial colonization traits (motility and biofilm) were examined and showed that only ECB140 produced flagellum and strong biofilms compared with other Enterococcus strains. Comparative genome sequence analyses showed that only ECB140 possessed a complete route for L-tryptophan synthesis among all 15 strains. High-performance liquid chromatography and qRT-PCR confirmed the capability of ECB140 to produce L-tryptophan. Besides, the genome also contains the biosynthesis pathways of several other essential amino acids, such as phenylalanine, threonine, valine, leucine, isoleucine and lysine. These results indicate that ECB140 has the ability to survive passage through the gut and could act as a candidate probiotic.

CONCLUSIONS

The study describes a novel, natural silkworm gut symbiont capable of producing L-tryptophan. Enterococcus casseliflavus ECB140 physical and genomic attributes offer possibilities for its colonization and provide L-tryptophan for lepidopteran insects.

Smad on X is vital for larval-pupal transition in a herbivorous ladybird beetle

Insect development is regulated by a combination of juvenile hormone (JH) and 20-hydroxyecdysone (20E). Production of both JH and 20E is regulated by transforming growth factor-β (TGFβ) signaling. TGFβ can be classified into two branches, the Activin and Bone Morphogenetic Protein (BMP) pathways. In Drosophila melanogaster, BMP signaling is critical for JH synthesis, whereas Activin signal is required to generate the large pulse of 20E necessary for entering metamorphosis. However, to which extent the roles of these signals are conserved remains unknown. Here we studied the role of an Activin component Smad on X (Smox) in post-embryonic development in a defoliating ladybird Henosepilachna vigintioctopunctata. RNA interference (RNAi)-aided knockdown of Hvsmox inhibited larval growth, and impaired larval development. All Hvmyo RNAi larvae arrested at the fourth-instar larval stage. Moreover, knockdown of Hvsmox delayed gut and Malpighian tubules remodeling. Furthermore, the expression of a JH biosynthesis gene (Hvjhamt), a JH receptor gene HvMet and a JH response gene HvKr-h1 was greatly enhanced. Conversely, the expression levels of an ecdysteroidogenesis gene (Hvspo), a 20E receptor gene (HvEcR) and six 20E response genes (HvBrC, HvE74, HvE75, HvE93, HvHR3 and HvHR4) were significantly lowered. Knockdown of HvMet partially restored the negative phenotypes in the Hvsmox RNAi beetles. Our results suggest that Smox exerts regulative roles in JH production, ecdysteroidogenesis and organ remodeling, thus contributing to modulate the larva-pupa-adult transformation in H. vigintioctopunctata.

Dissecting the Isoform-Specific Roles of FTZ-F1 in the Larval–Larval and Larval–Pupal Ecdyses in Henosepilachna vigintioctopunctata

Simple Summary

Fushi Tarazu Factor-1 (FTZ-F1) plays a crucial regulatory role in molting in insects. It is hypothesized that, by alternative transcription start and splicing, the FTZ-F1 gene generates two isomers (α- and βFTZ-F1) that exert isoform-specific roles in non-Drosophilid insects. In the present paper, we first unveiled that the same post-transcriptional processing in FTZ-F1 occurred in coleopterans, lepidopterans, dipterans and hymenopterans. We then found that αFTZ-F1 and βFTZ-F1 were actively transcribed throughout the development, from embryo to adult, in Henosepilachna vigintioctopunctata. Moreover, by RNA interference, we confirmed that both FTZ-F1 isoforms act as regulators in larval–larval molting and βFTZ-F1 is involved in the regulation of the larval–pupal transition.

Abstract

Fushi Tarazu Factor 1 (FTZ-F1), a member of the nuclear receptor superfamily, is the downstream factor of 20-hydroxyecdysone signaling. In Drosophila melanogaster, alternative transcription start and splicing in the FTZ-F1 gene generate αFTZ-F1 and βFTZ-F1 isoforms, which are vital for pair-rule segmentation in early embryogenesis and post-embryonic development, respectively. However, whether the same mRNA isoforms are present and exert the conservative roles remains to be clarified in other insects. In the present paper, we first mined the genomic data of representative insect species and unveiled that the same post-transcriptional processing in FTZ-F1 occurred in coleopterans, lepidopterans, dipterans and hymenopterans. Our expression data in Henosepilachna vigintioctopunctata, a serious polyphagous defoliator damaging a wide range of crops in Solanaceae and Cucurbitaceae, showed that both αFTZ-F1 and βFTZ-F1 were actively transcribed throughout the development, from embryo to adult. The RNA interference-aided knockdown of both isoforms completely arrested larval ecdysis from the third to the fourth instar, in contrast to the depletion of either isoform. In contrast, silencing βFTZ-F1, rather than αFTZ-F1, severely impaired the larval–pupal transformation. We accordingly propose that both FTZ-F1 isoforms are essential but mutually interchangeable for larval–larval molting, while βFTZ-F1 is necessary for the larval–pupal transition and sufficient to exert the role of both FTZ-F1s during larval–pupal metamorphosis in H. vigintioctopunctata.

Silencing of Adc and Ebony Causes Abnormal Darkening of Cuticle in Henosepilachna vigintioctopunctata

N-β-alanyldopamine (NBAD) is a precursor of N-acylquinone sclerotin utilized for cross-linking between cuticular proteins for cuticle during insect molting. The importance of NBAD in cuticle tanning has not been well compared among different developing stages of insects. Henosepilachna vigintioctopunctata, a typical polyphagous pest feeding on a large number of Solanaceae and Cucurbitaceae plants in Asian countries, displays diverse cuticle pigmentation patterns among developing stages and body regions. Here, we found that the expression of three genes (Hvadc, Hvebony, and Hvtan) involved in NBAD biosynthesis peaked in the 4-day-old pupae or 0-day-old adults of H. vigintioctopunctata. At the first, second, third, and fourth larval instar and pupal stage, their transcript levels were high just before and/or right after the molting. Moreover, they were more abundantly transcribed at the larval heads than in the bodies. RNA interference (RNAi) of either Hvadc or Hvebony at the third instar larvae selectively deepened the color of the larval head capsules, antennae, mouthpart, scoli, strumae, and legs; and depletion of the two genes blackened the pupal head capsules, antennae, mouthpart, and legs. However, the knockdown of either Hvadc or Hvebony darkened the whole bodies of the adults. Conversely, RNAi of Hvtan at the third instar stage had little influence on the pigmentation in the larvae, pupae, and adults. These findings demonstrated that Adc and Ebony are important in cuticle pigmentation of H. vigintioctopunctata and suggested that larger quantities of NBAD were present in adults and play more important roles in pigmentation than larvae/pupae.

Yellow-b, -c, -d, and -h are required for normal body coloration of Henosepilachna vigintioctopunctata

The involvement of yellow genes y-b, y-c, y-e, and y-h in cuticle tanning has poorly been clarified. In the present paper, six putative yellow (y-y, y-b, y-c, y-e y-f, and y-h) genes were identified in Henosepilachna vigintioctopunctata. Hvy-b, Hvy-c, Hvy-e, and Hvy-h were abundantly transcribed at early larval and late pupal stages, especially in the epidermis. Accordingly, RNA interference (RNAi) experiments were performed by an injection of dsy-b, dsy-c, dsy-e, or dsy-h into the second instar larvae and 1-day-old pupae. The head capsule, scoli and strumae, and legs in the fourth-instar larvae became blacker; the blackish spots in the pupae were darkened and widened after RNAi of Hvy-b, compared with those of dsegfp-treated controls. Depletion of Hvy-b at the 1-day-old pupal stage expanded two pair of black markings on the sternum of the metathorax, and darkened the black patched on the sterna of the abdomen segments I-VI in the resultant adults. Depletion of Hvy-e caused darker pigmented adult body and elytral cuticles than those of dsegfp-introduced controls. However, there was no obvious difference in pigmentation of the black markings. Hvy-h-deficient larvae displayed dark yellow body color, whereas the body color of the dsegfp-injected control was pale yellow. There was no obvious difference in coloration of larval specific-black markings or pupal cuticle between dsHvy-h- and dsegfp-treated animals. Moreover, silence of Hvy-c at the second instar larval stage lightened black markings in the resulting larvae and pupae, but had no influence on pale yellow body color. Our results demonstrated their different roles of the four yellow genes during body pigmentation: HvY-b and HvY-c, respectively, inhibit and facilitate the coloration within dark markings, whereas HvY-e and HvY-h, respectively, repress the pigmentation in adult and larval body cuticles outside the black patches in H. vigintioctopunctata.

Knockdown of Vacuolar ATPase Subunit G Gene Affects Larval Survival and Impaired Pupation and Adult Emergence in Henosepilachna vigintioctopunctata

Simple Summary

Vacuolar ATPase (vATPase), a proton pump driven by ATP hydrolysis, acts as a membrane energizer to motivate the movement of ions and nutrients across the cellular membrane in insect guts and Malpighian tubules, among others. The vATPase holoenzyme contains 16 subunits. Out of these subunits, mammalian G subunit includes three isoforms (G1-G3) which are encoded by three distinctive genes. The physiological role of a specific G isoform can be compensated by others. Thus, current experimental evidence on the in vivo function of G is rather limited among eight V₁ subunits. In the present paper, particular attention was paid to an insect model, Henosepilachna vigintioctopunctata ladybird, a serious defoliator of Solanaceae and Cucurbitaceae plants in many Asian countries. Given that the beetle is sensitive to RNA interference (RNAi), HvvATPaseG gene was knocked down by ingestion of its corresponding dsRNA at the fourth-instar larval stage. Silence of HvvATPaseG affected larval growth and survival, impaired pupation and adult emergence. Our results provide a basis for further functional research on the vATPase G subunit in insects and suggest new ideas for the management of H. vigintioctopunctata.

Abstract

The vATPase holoenzyme consists of two functional subcomplexes, the cytoplasmic (peripheral) V₁ and the membrane-embedded V₀. Both V₁ and V₀ sectors contain eight subunits, with stoichiometry of A₃B₃CDE₃FG₃H in V₁ and ac₈c’c”def(Voa1p) in V₀ respectively. However, the function of G subunit has not been characterized in any non-Drosophilid insect species. In the present paper, we uncovered that HvvATPaseG was actively transcribed from embryo to adult in a Coleopteran pest Henosepilachna vigintioctopunctata. Its mRNA levels peaked in larval hindgut and Malpighian tubules. RNA interference (RNAi)-mediated knockdown of HvvATPaseG significantly reduced larval feeding, affected chitin biosynthesis, destroyed midgut integrity, damaged midgut peritrophic membrane, and retarded larval growth. The function of Malpighian tubules was damaged, the contents of glucose, trehalose, lipid, total soluble amino acids and protein were lowered and the fat bodies were lessened in the HvvATPaseG RNAi larvae, compared with those in the PBS- and dsegfp-fed beetles. In contrast, the amount of glycogen was dramatically increased in the HvvATPaseG depletion ladybirds. As a result, the development was arrested, pupation was inhibited and adult emergence was impaired in the HvvATPaseG hypomorphs. Our results demonstrated that G subunit plays a critical role during larval development in H. vigintioctopunctata.