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The egg parasitoid Mesocomys trabalae Yao, Yang, and Zhao is used as a biocontrol agent against the emerging defoliator pest Caligula japonica Moore in East Asia. It has been proven that the eggs of Antheraea pernyi Guérin-Méneville can be used as a factitious host for the mass production of M. trabalae. We examined the parasitic behavior and morphological characteristics of the developmental stages of M. trabalae reared on A. pernyi eggs. The parasitic behavior of M. trabalae encompasses 10 steps, involving searching, antennation, locating the oviposition site, drilling, probing, detecting, oviposition, host feeding, grooming, and resting, with the oviposition step further divided into 3 stages. We determined that the parasitoid released an egg during the second stage of the oviposition step, while her body remained in a relatively static state. Among all the steps in parasitic behavior, probing occupied the longest time, accounting for 26.33% of the entire parasitism process. It was followed by oviposition (15.88%), drilling (15.10%), antennation (13.09%), detecting (10.79%), host feeding (10.02%), and the remaining steps, each occupying less than 5.00% of the total time in steps. The pre-emergence of adult M. trabalae comprised of 4 stages: egg (0–1 day), larva (2–6 days), prepupa (7–11 days), pupa (12–20 days), followed by the development into an adult, and it usually took 20–22 days to develop from an egg into an adult at 25°C. This study advances our understanding of the biology of Mesocomys parasitoids and their mass-rearing for use in augmentation programs. [ABSTRACT FROM AUTHOR]

Kriechbaumerella dendrolimi (Hymenoptera, Chalcididae) is a dominant pupal parasitoid species of various significant pine caterpillars, including Dendrolimus houi Lajonquiere (Lepidoptera, Lasiocampidae), with great potential for utilization. So far, the mass rearing of K. dendrolimi has been successfully established using Antheraea pernyi (Lepidoptera, Saturniidae) pupae as alternative hosts and released in the forest to suppress D. houi populations. However, the outcome is still expected to be improved due to lower parasitism rates, which might be related to the autonomous immune function of A. pernyi pupae. In our study, we investigated the effects of K. dendrolimi parasitization on the immune responses of A. pernyi pupae by measuring the expression of key immune factors: superoxide dismutase (SOD), polyphenol oxidases (PPOs), Attacin, Lysozymes (LYSs), and serine proteases (PRSSs). Our results show that parasitization significantly upregulated these immune factors, with distinct temporal patterns observable between 4 and 48 h post-parasitization. This upregulation highlights a robust immune response, adapting over time to the parasitic challenge. These findings suggest that specific immune mechanisms in A. pernyi pupae are activated in response to K. dendrolimi, shedding light on potential targets for enhancing host resistance. Metabolomic analyses complemented these findings by illustrating the broader metabolic shifts associated with the immune response. Specifically, Attacin was significantly upregulated twice, hypothesizing that the parasitoid's venom contains at least two parasitic factors. Metabolomics analysis revealed a significant metabolite difference within parasitized A. pernyi pupae. The highest number of differential expression metabolites (DEMs) was observed at 16 h post-parasitism (1184 metabolites), with fewer DEMs at 8 h (568 metabolites) and 32 h (693 metabolites), suggesting a close relationship between parasitism duration and the number of DEMs. These fluctuations reflected the fundamental process of immune interaction. KEGG enrichment results showed that the DEMs were mainly enriched in energy metabolism and immune-related pathways, indicating that parasitism is a process of continuous consumption and immune interaction in the host. These DEMs could also become future targets for regulating the immune functions of A. pernyi pupae and could provide reference data for optimizing mass-rearing techniques. [ABSTRACT FROM AUTHOR]

Kriechbaumerella dendrolimi (Hymenoptera, Chalcididae) is a dominant pupal parasitoid species of various significant pine caterpillars, including Dendrolimus houi Lajonquiere (Lepidoptera, Lasiocampidae), with great potential for utilization. So far, the mass rearing of K. dendrolimi has been successfully established using Antheraea pernyi (Lepidoptera, Saturniidae) pupae as alternative hosts and released in the forest to suppress D. houi populations. However, the outcome is still expected to be improved due to lower parasitism rates, which might be related to the autonomous immune function of A. pernyi pupae. In our study, we investigated the effects of K. dendrolimi parasitization on the immune responses of A. pernyi pupae by measuring the expression of key immune factors: superoxide dismutase (SOD), polyphenol oxidases (PPOs), Attacin, Lysozymes (LYSs), and serine proteases (PRSSs). Our results show that parasitization significantly upregulated these immune factors, with distinct temporal patterns observable between 4 and 48 h post-parasitization. This upregulation highlights a robust immune response, adapting over time to the parasitic challenge. These findings suggest that specific immune mechanisms in A. pernyi pupae are activated in response to K. dendrolimi, shedding light on potential targets for enhancing host resistance. Metabolomic analyses complemented these findings by illustrating the broader metabolic shifts associated with the immune response. Specifically, Attacin was significantly upregulated twice, hypothesizing that the parasitoid’s venom contains at least two parasitic factors. Metabolomics analysis revealed a significant metabolite difference within parasitized A. pernyi pupae. The highest number of differential expression metabolites (DEMs) was observed at 16 h post-parasitism (1184 metabolites), with fewer DEMs at 8 h (568 metabolites) and 32 h (693 metabolites), suggesting a close relationship between parasitism duration and the number of DEMs. These fluctuations reflected the fundamental process of immune interaction. KEGG enrichment results showed that the DEMs were mainly enriched in energy metabolism and immune-related pathways, indicating that parasitism is a process of continuous consumption and immune interaction in the host. These DEMs could also become future targets for regulating the immune functions of A. pernyi pupae and could provide reference data for optimizing mass-rearing techniques.

Detection of sex pheromones of insects relies on the antennae. The female pheromone signal transmission in the male antennae ultimately initiates the courtship and mating behaviors of males. To investigate the proteins and metabolites involved in this neural transduction, integrative proteomics and metabolomics analysis including tandem mass tag (TMT) proteomic quantification and liquid chromatography tandem mass spectrometry (LC/MS)-based metabolomics was adopted for comparing proteomic and metabolic changes between the antennae of male moths following stimulation by females and the non-stimulated males of Antheraea pernyi (Guérin-Méneville, Lepidoptera: Saturniidae) in this study. A total of 92 differentially expressed proteins (DEPs) containing 52 upregulated and 40 downregulated proteins and 545 differentially expressed metabolites (DEMs) including 218 upregulated and 327 downregulated metabolites were identified from the antennae of female-stimulated male moths based on the proteome and metabolome data, respectively. Bioinformatics analysis was performed for the 45 DEPs and 160 DEMs, including Gene Ontology (GO), Clusters of Orthologous Groups (COG), and Kyoto Encylopaedia of Genes and Genomes (KEGG) enrichment analysis and Human Metabolome Database (HMDB) annotation. A number of DEPs and DEMs related to neural transmission of female pheromone signals in the male antennae of A. pernyi were screened, including tyrosine hydroxylase, cryptochrome-1, tachykinin, arylalkylamine N -acetyltransferase, cadherin-23, glutathione S -transferase delta 3, tyramine, tryptamine, n-oleoyl dopamine, n-stearoyl dopamine, and n-stearoyl tyrosine. The altered expression levels of those proteins or metabolites were speculated involved in regulating the neuron activity for enhanced transmission of neural impulses and continuous perception, reception, and transduction of female pheromone signals. Our findings yielded novel insights into the potential mechanisms in the antennae of male A. pernyi responding to female attraction. [ABSTRACT FROM AUTHOR]

Toll-interacting protein (Tollip) participates in multiple biological processes. However, the biological functions of Tollip proteins in insects remain to be further explored. Here, the genomic sequence of tollip gene from Antheraea pernyi (named Ap-Tollip) was identified with a length of 15,060 bp, including eight exons and seven introns. The predicted Ap-Tollip protein contained conserved C2 and CUE domains and was highly homologous to those tollips from invertebrates. Ap-Tollip was highly expressed in fat body compared with other determined tissues. As far as the developmental stages were concerned, the highest expression level was found at the 14th day in eggs or the 3rd day of the 1st instar. Ap-Tollip was also obviously regulated by lipopolysaccharide, polycytidylic acid or 20E in different tissues. In addition, the interaction between Ap-Tollip and ubiquitin was confirmed by western blotting and pull-down assay. RNAi of Ap-Tollip significantly affected the expression levels of apoptosis and autophagy-related genes. These results indicated that Ap-Tollip was involved in immunity and development of A. pernyi. [ABSTRACT FROM AUTHOR]

For a half-century, the commercial wild silkworm, Antheraea pernyi, has been protected by coumaphos, which is an internal organophosphorus insecticide used to kill the potential parasitic fly larvae inside. Knowledge about the detoxification genes of A. pernyi as well as the detoxification mechanism for this species remains severely limited. In this study, we identified 281 detoxification genes (32 GSTs, 48 ABCs, 104 CYPs, and 97 COEs) in the genome of this insect, which are unevenly distributed over 46 chromosomes. When compared to the domesticated silkworm, Bombyx mori, a lepidopteran model species, A. pernyi has a similar number of ABCs, but a greater number of GSTs, CYPs, and COEs. By transcriptome-based expression analysis, we found that coumaphos at a safe concentration level significantly changed the pathways related to ATPase complex function and the transporter complex in A. pernyi. KEGG functional enrichment analysis indicated that protein processing in the endoplasmic reticulum was the most affected pathway after coumaphos treatment. Finally, we identified four significantly up-regulated detoxification genes (ABCB1, ABCB3, ABCG11, and ae43) and one significantly down-regulated detoxification gene (CYP6AE9) in response to coumaphos treatment, suggesting that these five genes may contribute to detoxification of coumaphos in A. pernyi. Our study provides the first set of detoxification genes for wild silkworms from Saturniidae and highlights the importance of detoxification gene repertoire in insect pesticide tolerance. [ABSTRACT FROM AUTHOR]

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Antheraea pernyi is one of the most famous edible and silk-producing wild silkworms of Saturniidae. Structural cuticular proteins (CPs) are the primary component of insect cuticle. In this paper, the CPs in the genome of A. pernyi were identified and compared with those of the lepidopteran model species Bombyx mori, and expression patterns were analyzed based on the transcriptomic data from the larval epidermis/integument (epidermis in the following) and some non-epidermis tissues/organs of two silkworm species. A total of 217 CPs was identified in the A. pernyi genome, a comparable number to B. mori (236 CPs), with CPLCP and CPG families being the main contribution to the number difference between two silkworm species. We found more RR-2 genes expressed in the larval epidermis of fifth instar of A. pernyi than B. mori, but less RR-2 genes expressed in the prothoracic gland of A. pernyi than B. mori, which suggests that the hardness difference in the larval epidermis and prothoracic gland between the two species may be caused by the number of RR-2 genes expressed. We also revealed that, in B. mori, the number of CP genes expressed in the corpus allatum and prothoracic gland of fifth instar was higher than that in the larval epidermis. Our work provided an overall framework for functional research into the CP genes of Saturniidae. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chouioia cunea is a generalist pupal endoparasitoid. Native to Eurasia, the parasitoid has been mass‐reared on an alternative lepidopteran host (Antheraea pernyi) to successfully control the exotic invasive lepidopteran pest Hyphantria cunea in China. To solicit more accessible hosts, this study evaluated the potential of an easily cultured coleopteran beetle (Tenebrio molitor) as a substitute for rearing C. cunea through comparing the relative performance of the parasitoids reared from both alternative hosts on H. cunea. RESULTS: Compared with those reared from A. pernyi, the parasitoids reared from T. molitor (i.e., T. molitor vs. A. pernyi groups) performed equally well in terms of parasitism rate (94.4 vs. 88.9%), number of offspring produced per parasitized host (278 vs. 286), and female body length (1.334 vs. 1.351 mm), hind‐tibia length (0.322 vs. 0.324 mm) and number of mature oocytes in the ovarioles (171 vs. 187), or even better based on offspring pre‐emergence time (16.0 vs 16.9 days) and percentages of emerged offspring (99.8 vs. 99.1%) and female offspring (97.1 vs. 91.3%). Flight performance testing indicated that young C. cunea adults emerged from T. molitor had a similar percentage of actively flying wasps (76.9 vs. 72.9%) and a lower percentage of inactive wasps (2.3 vs. 10.6%) when compared to those reared from A. pernyi. CONCLUSION: Given the remarkable adaptability of C. cunea and the vast availability of T. molitor as a common resource insect worldwide, this indigenous parasitoid could be mass‐reared on T. molitor to improve the prospect of biological control of H. cunea in its invaded regions. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract Background Cocoonase is a serine protease present in sericigenous insects and majorly involved in dissolving of sericin protein allowing moth to escape. Cocoon structure is made up of sericin protein which holds fibroin filaments together. Cocoonase enzyme hydrolyzes sericin protein without harming the fibroin. However, until date, no detailed characterization of cocoonase enzyme and its presence in wild silk moth Antheraea mylitta has been carried out. Therefore, current study aimed for detailed characterization of amplified cocoonase enzyme, secondary and tertiary structure prediction, sequence and structural alignment, phylogenetic analysis, and computational validation. Several computational tools such as ProtParam, Iterative Threading Assembly Refinement (I-TASSER), PROCHECK, SAVES v6.0, TM-align, Molecular Evolutionary Genetics Analysis (MEGA) X, and Figtree were employed for characterization of cocoonase protein. Results The present study elucidates about the isolation of RNA, cDNA preparation, PCR amplification, and in silico characterization of cocoonase from Antheraea mylitta. Here, total RNA was isolated from head region of A. mylitta, and gene-specific primers were designed using Primer3 followed by PCR-based amplification and sequencing. The newly constructed 377-bp length sequence of cocoonase was subjected to in silico characterization. In silico study of A. mylitta cocoonase showed 26% similarity to A. pernyi strain Qing-6 cocoonase using Blastp and belongs to member of chymotrypsin-like serine protease superfamily. From phylogenetic study, it was found that A. mylitta cocoonase sequence is closely related to A. pernyi cocoonase sequence. Conclusions The present study revealed about the detailed in silico characterization of cocoonase gene and encoded protein obtained from A. mylitta head region. The results obtained infer the presence of cocoonase enzyme in the wild silkworm A. mylitta and can be used for cocoon degumming which will be a valuable and cost-effective strategy in silk industry.

To study the effect of truncated ApEGF on wound healing in vitro, scratches were made in HaCaT cell cultures, which were then allowed to re-epithelialize for 48 h at 37 °C in the presence or absence of ApEGF. Therefore, rapid treatment is required to recover damaged skin tissues, and wound healing using appropriate wound treatments is essential. Compared to the control group, the truncated ApEGF group exhibited significant wound healing on day 3, and by day 15, the wounds in the truncated ApEGF group had fully healed. Keywords: wound healing; Antheraea pernyi; epidermal growth factor; prokaryotic expression; re-epithelialization EN wound healing Antheraea pernyi epidermal growth factor prokaryotic expression re-epithelialization 975 13 11/17/22 20221101 NES 221101 1. [Extracted from the article]

The M14 family metal carboxypeptidase genes play an important role in digestion and pathogenic infections in the gut of insects. However, the roles of these genes in Antheraea pernyi (Guérin-Méneville, 1855) remain to be analyzed. In the present study, we cloned a highly expressed M14 metal carboxypeptidase gene (ApMCP1) found in the gut and discovered that it contained a 1,194 bp open reading frame encoding a 397-amino acid protein with a predicted molecular weight of 45 kDa. Furthermore, 14 members of the M14 family metal carboxypeptidases (ApMCP1–ApMCP14) were identified in the A. pernyi genome, with typical Zn_pept domains and two Zn-anchoring motifs, and were further classified into M14A, M14B, and M14D subfamilies. Expression analysis indicated that ApMCP1 and ApMCP9 were mainly expressed in the gut. Additionally, we observed that ApMCP1 and ApMCP9 displayed opposite expression patterns after starvation, highlighting their functional divergence during digestion. Following natural infection with baculovirus NPV, their expression was significantly upregulated in the gut of A. pernyi. Our results suggest that the M14 family metal carboxypeptidase genes are conservatively digestive enzymes and evolutionarily involved in exogenous pathogenic infections. [ABSTRACT FROM AUTHOR]

Background: Caligula japonica, commonly known as Japanese giant silkworm (JGS), is a serious defoliating pest of fruit and forest trees in East Asia. To develop eco-friendly and cost-effective control methods for this pest, we evaluated the potential for biological control of JGS using its egg parasitoid Anastatus gansuensis reared on the Chinese oak silkworm (COS) Antheraea pernyi. We compared the reproductive traits and population increase potential of the parasitoid on JGS and COS eggs, as well as its functional response to host egg densities and mutual interference at different parasitoid densities., Results: Anastatus gansuensis was confirmed to be strictly synovigenic, with most eggs maturing post-emergence, and produced <1% male offspring on both host eggs. Although A. gansuensis females reared from COS eggs had longer longevity and oviposition period, and higher fecundity and net reproductive rate compared to those reared from JGS eggs, the parasitoid had a higher intrinsic rate of increase on JGS than COS eggs. The parasitoid exhibited a type II functional response to increasing host densities, with mutual interference among foraging female wasps occurred at higher parasitoid densities., Conclusion: Our results indicate a high potential for biological control of JGS using A. gansuensis. The parasitoid can be efficiently reared on COS eggs and used against JGS. It may be essential to provide food for emerging adult parasitoids allowing time for egg maturation prior to the rearing or augmentative release of the parasitoid. Some mutual interference at high parasitoid rearing densities likely reduces per capita parasitization efficiency of A. gansuensis. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

For a half-century, the commercial wild silkworm, Antheraea pernyi, has been protected by coumaphos, which is an internal organophosphorus insecticide used to kill the potential parasitic fly larvae inside. Knowledge about the detoxification genes of A. pernyi as well as the detoxification mechanism for this species remains severely limited. In this study, we identified 281 detoxification genes (32 GSTs, 48 ABCs, 104 CYPs, and 97 COEs) in the genome of this insect, which are unevenly distributed over 46 chromosomes. When compared to the domesticated silkworm, Bombyx mori, a lepidopteran model species, A. pernyi has a similar number of ABCs, but a greater number of GSTs, CYPs, and COEs. By transcriptome-based expression analysis, we found that coumaphos at a safe concentration level significantly changed the pathways related to ATPase complex function and the transporter complex in A. pernyi. KEGG functional enrichment analysis indicated that protein processing in the endoplasmic reticulum was the most affected pathway after coumaphos treatment. Finally, we identified four significantly up-regulated detoxification genes (ABCB1, ABCB3, ABCG11, and ae43) and one significantly down-regulated detoxification gene (CYP6AE9) in response to coumaphos treatment, suggesting that these five genes may contribute to detoxification of coumaphos in A. pernyi. Our study provides the first set of detoxification genes for wild silkworms from Saturniidae and highlights the importance of detoxification gene repertoire in insect pesticide tolerance.

The Antheraea Pernyi silk gland protein originates from natural organisms and synthesized by tussah silk glands and has widely potential biomaterial applications due to the superior biocompatibility. This study investigates the Antheraea Pernyi silk gland protein-based drug-loaded bio-hydrogels for bioengineered tissue fabricated by using an eco-friendly method without the harsh extracting process and the usage of toxic chemicals. The drug-loaded bio-hydrogels exhibited a porous structure and interconnected pore walls. The swelling ratio and water absorption of drug-loaded bio-hydrogels were, respectively, above 95% and 1.5 × 103%. The cumulative release of drug loaded hydrogels all reached more than 90% within 4 h, and this indicates the potential of drug-loaded hydrogels as future drug-carrying biomaterials. RSC96 Schwann cells cultured on drug-loaded hydrogels for 72 h under cell culture medium show no toxic effects and more pro-proliferative effects. The results suggest the suitability of drug-loaded bio-hydrogels as natural biopolymer for the potential in vitro RSC96 cell culture platform and other biomaterial applications. [ABSTRACT FROM AUTHOR]

The pupal diapause of univoltine Antheraea pernyi hampers sericultural and biotechnological applications, which requires a high eclosion incidence after artificial diapause termination to ensure production of enough eggs. The effect of pupal diapause termination using 20-hydroxyecdysone (20E) on the eclosion incidence has not been well-documented in A. pernyi. Here, the dosage of injected 20E was optimized to efficiently terminate pupal diapause of A. pernyi, showing that inappropriate dosage of 20E can cause pupal lethality and a low eclosion incidence. The optimal ratio of 20E to 1- month-old pupae was determined as 6 μg/g. Morphological changes showed visible tissue dissociation at 3 days post-injection (dpi) and eye pigmentation at 5 dpi. Comprehensive transcriptome analysis identified 1,355/1,592, 494/203, 584/297, and 1,238/1,404 upregulated and downregulated genes at 1, 3, 6, and 9 dpi, respectively. The 117 genes enriched in the information processing pathways of “signal transduction” and “signaling molecules and interaction” were upregulated at 1 and 3 dpi, including the genes involved in FOXO signaling pathway. One chitinase, three trehalase, and five cathepsin genes related to energy metabolism and tissue dissociation showed high expression levels at the early stage, which were different from the upregulated expression of four other chitinase genes at the later stage. Simultaneously, the expression of several genes involved in molting hormone biosynthesis was also activated between 1 and 3 dpi. qRT-PCR further verified the expression patterns of two ecdysone receptor genes (EcRB1 and USP) and four downstream response genes (E93, Br-C, βFTZ-F1, and cathepsin L) at the pupal and pharate stages, respectively. Taken together, these genes serve as a resource for unraveling the mechanism underlying pupal-adult transition; these findings facilitate rearing of larvae more than once a year and biotechnological development through efficient termination of pupal diapause in A. pernyi in approximately half a month. [ABSTRACT FROM AUTHOR]

Antheraea pernyi is one of the most famous edible and silk-producing wild silkworms of Saturniidae. Structural cuticular proteins (CPs) are the primary component of insect cuticle. In this paper, the CPs in the genome of A. pernyi were identified and compared with those of the lepidopteran model species Bombyx mori, and expression patterns were analyzed based on the transcriptomic data from the larval epidermis/integument (epidermis in the following) and some non-epidermis tissues/organs of two silkworm species. A total of 217 CPs was identified in the A. pernyi genome, a comparable number to B. mori (236 CPs), with CPLCP and CPG families being the main contribution to the number difference between two silkworm species. We found more RR-2 genes expressed in the larval epidermis of fifth instar of A. pernyi than B. mori, but less RR-2 genes expressed in the prothoracic gland of A. pernyi than B. mori, which suggests that the hardness difference in the larval epidermis and prothoracic gland between the two species may be caused by the number of RR-2 genes expressed. We also revealed that, in B. mori, the number of CP genes expressed in the corpus allatum and prothoracic gland of fifth instar was higher than that in the larval epidermis. Our work provided an overall framework for functional research into the CP genes of Saturniidae.

In insects, melanism plays important roles in defense, immunoreactions, and body color. The underlying molecular mechanisms of melanism in different insects are diverse and remain elusive. In contrast to another silkworm, Bombyx mori , the Chinese oak silkworm, Antheraea pernyi , produces melanic pupae under natural environmental conditions. DOPA and dopamine synthesis are crucial for melanin formation. Disruption of these processes reportedly influences body colors in many insects. Most research focuses on newly emerged pupae, and the larval process preceding pupation remains unknown. Due to the large size and long pupation period in A. pernyi , the entire process was studied at least every 12 h. The expression patterns of tyrosine hydroxylase (TH) and DOPA decarboxylase (DDC), which are involved in DOPA and dopamine synthesis in the epidermis, were evaluated during larval–pupal metamorphosis. We also performed RNA interference (RNAi) and used enzyme inhibitors to examine morphological changes. The amino acid sequences of TH and DDC share 90.91% and 86.64% identity with those of B. mori. TH and DDC expression was upregulated during the 48–72 h period prior to pupal emergence, especially at 60 h. RNAi of TH and DDC induced partial melanism in some pupae. The inhibitors 3-iodo-tyrosine (3-IT) and L-α-methyl-DOPA (L-DOPA) influenced pupal melanization. Different concentrations of inhibitors led to pupal deformity and even mortality. Four different monoamines, only DOPA and Dopamine synthezed from Tyrosine will be influenced by TH and DDC inhibitor. These results indicate that TH and DDC are key genes associated with pupal melanization during larval–pupal transformation in A. pernyi. Overall, our results suggest that TH and DDC expression alterations in a particular stage can affect body color, setting the molecular basis for artificial control of pupal melanization. [ABSTRACT FROM AUTHOR]

Simple Summary: Japanese giant silkworm (JGS), Caligula japonica Moore, is an emerging defoliator pest of forest and fruit trees in East Asia, causing severe economic losses. In this study, we used eggs of the Chinese oak silkworm (COS), Antheraea pernyi Guérin-Méneville, as an alternative host to rear the dominant JGS egg parasitoid, Anastatus japonicus Ashmead. We showed that A. japonicus could be efficiently reared on COS eggs. Furthermore, A. japonicus reared from COS eggs had a high biological control potential against JGS. This study provides useful information on the demography, parasitism rate, and rearing methods of A. japonicus on COS eggs and the basis for developing a cost-effective biological control program against JGS using A. japonicus. Japanese giant silkworm (JGS), Caligula japonica Moore, is an emerging defoliator pest of forest and fruit trees in East Asia, causing severe economic losses. To develop a cost-effective biological control program against JGS, we used eggs of the Chinese oak silkworm (COS) Antheraea pernyi Guérin-Méneville as an alternative host to rear the most dominant JGS egg parasitoid Anastatus japonicus Ashmead. We compared the demographic parameters and total parasitism (killing) rates of A. japonicus parasitizing JGS and COS eggs using an age-stage, two-sex life table method. The results showed that A. japonicus performed differently on these two different hosts. Anastatus japonicus reared from COS eggs had a higher fecundity (369.7 eggs per female) and a longer oviposition period (35.9 days) on the COS than JGS eggs (180.9 eggs; 24.0 days). Consequently, A. japonicus parasitizing COS eggs had a higher intrinsic rate of increase (r = 0.1466 d−1), finite rate of increase (λ = 1.1579 d−1) and net reproductive rate (R0 = 284.9 offspring) than those parasitizing JGS eggs (r = 0.1419 d−1, λ = 1.1525 d−1, R0 = 150.0 offspring). The total net parasitism rate (the number of parasitized hosts in which the parasitoids successfully developed) of A. japonicus parasitizing COS eggs was 284.9, significantly higher than that of A. japonicus parasitizing JGS eggs (150.0), while the net non-effective parasitism rate (the number of parasitized hosts in which the parasitoids failed to develop) of the former (0.0) was significantly lower than that of the latter (9.6). These results suggest that A. japonicus can be efficiently reared on the alternative (or factitious) COS eggs, and the reared parasitoids have a high biological control potential against the target JGS. [ABSTRACT FROM AUTHOR]

Uranium (U) is one of the heavest metals in nature, which has been mainly used in atomic energy industrial system, but its toxic effects on most organisms are largely remained unknown especially in insects. Antheraea pernyi pupae were injected with uranyl acetate, which concentrations were 6.25mM, 12.5mM, 25mM. Changes in malondialdehyde (MDA) and reduced glutathione (GSH) and activities of superoxide dismutase (SOD), and catalase (CAT) as well as their corresponding mRNA levels in the fat bodies of the pupae were evaluated. As a result, we found that the contents of MDA were increased at 4 h and then decreased compared with control. And, the contents of GSH were decreased gradually. However, the activities of catalase were inhibited and the trend of SOD activity changes was down-regulation in a time-dependent manner with higher concentration treatments. The changing trends in the mRNA levels of these enzymes were not always consistent with those of enzymatic activities. The fat body of A. pernyi, as an important antioxidant tissue, can increase the expression of oxido-reductas system enzymes by promoting the expression of SOD, CAT, GST and glutathione peroxidase (GSH-Px) to improve the body’s response to heavy metal stimulation injury. Our results collectively support a relationship between uranyl acetate and alterations in the levels of antioxidant enzymes in A. pernyi fatbodies. The activities and expression of reactive oxygen species (ROS) enzymes can be used as a biomarker for detection of heavy metal contamination. [ABSTRACT FROM AUTHOR]

In insects, melanism plays important roles in defense, immunoreactions, and body color. The underlying molecular mechanisms of melanism in different insects are diverse and remain elusive. In contrast to another silkworm, Bombyx mori, the Chinese oak silkworm, Antheraea pernyi, produces melanic pupae under natural environmental conditions. DOPA and dopamine synthesis are crucial for melanin formation. Disruption of these processes reportedly influences body colors in many insects. Most research focuses on newly emerged pupae, and the larval process preceding pupation remains unknown. Due to the large size and long pupation period in A. pernyi, the entire process was studied at least every 12 h. The expression patterns of tyrosine hydroxylase (TH) and DOPA decarboxylase (DDC), which are involved in DOPA and dopamine synthesis in the epidermis, were evaluated during larval–pupal metamorphosis. We also performed RNA interference (RNAi) and used enzyme inhibitors to examine morphological changes. The amino acid sequences of TH and DDC share 90.91% and 86.64% identity with those of B. mori. TH and DDC expression was upregulated during the 48–72 h period prior to pupal emergence, especially at 60 h. RNAi of TH and DDC induced partial melanism in some pupae. The inhibitors 3-iodo-tyrosine (3-IT) and L-α-methyl-DOPA (L-DOPA) influenced pupal melanization. Different concentrations of inhibitors led to pupal deformity and even mortality. Four different monoamines, only DOPA and Dopamine synthezed from Tyrosine will be influenced by TH and DDC inhibitor. These results indicate that TH and DDC are key genes associated with pupal melanization during larval–pupal transformation in A. pernyi. Overall, our results suggest that TH and DDC expression alterations in a particular stage can affect body color, setting the molecular basis for artificial control of pupal melanization.

Antheraea pernyi (Guérin-Méneville 1855) is an important resource for silk, food, and biohealth products; however, exogenous pathogens largely affect the commercial application potential of this species. Since the gut is a key organ for the digestion and absorption of nutrients as well as for immune defense, we used comparative transcriptome analysis to screen for a gut-specific molecular tool for further functional research in A. pernyi. In total, 3,331 differentially expressed genes (DEGs) were identified in the gut compared with all other pooled tissues of A. pernyi, including 1,463 upregulated genes in the gut. Among these, we further focused on a lipopolysaccharide-induced tumor necrosis factor-α factor (LITAF) gene because of its high gut-specific expression and the presence of a highly conserved SIMPLE-like domain, which is related to the immune response to pathogenic infections in many species. The cDNA sequence of ApLITAF was 447-bp long and contained a 243-bp open reading frame encoding an 80-amino acid protein. Immune challenge assays indicated that ApLITAF expression was significantly upregulated in the gut of A. pernyi naturally infected with nucleopolyhedrovirus (NPV) or fed leaves infected with the gram-negative bacterium Escherichia coli (Migula 1895) and the gram-positive bacterium Bacillus subtilis (Ehrenberg 1835). Cell transfection showed that ApLITAF localized to the lysosome. Collectively, these results suggested that ApLITAF played a role in the immune response of A. pernyi and could facilitate the future research and breeding application in this species. [ABSTRACT FROM AUTHOR]

The cell line NISES-AnPe-428 (AnPe), derived from the Chinese oak silkworm Antheraea pernyi, was characterized for its permissiveness and productivity for six different nucleopolyhedrovirus (NPV) species. These NPVs included homologous Antheraea pernyi NPV (AnpeNPV) and heterologous Autographa californica multiple NPV (AcMNPV), Bombyx mori NPV (BmNPV), Hyphantria cunea MNPV (HycuMNPV), Spodoptera exigua MNPV (SeMNPV), and Lymantria dispar MNPV (LdMNPV), representing viruses that had been isolated from insect species belonging to five different families (Saturniidae, Noctuidae, Bombycidae, Arctiidae, and Lymantriidae). We found that AnPe cells supported productive replication of AnpeNPV, AcMNPV, BmNPV, HycuMNPV, and SeMNPV to varying degrees. Upon infection with SeMNPV, a subset of AnPe cell population in the culture underwent apoptosis, while remaining cells produced limited amounts of progeny virions and polyhedra. AnPe cells were refractory to LdMNPV infection and failed to support replication of viral DNA, indicating that viral replication was restricted at or prior to the step of viral DNA replication. These results indicated that AnPe cells have the potential to provide excellent systems for studying the molecular mechanisms underlying cellular permissiveness for NPV replication and host-range determination of NPVs. [ABSTRACT FROM AUTHOR]

To evaluate the wound-healing effect of Antheraea pernyi epidermal growth factor (ApEGF), we performed the sequence analysis, cloning, and prokaryotic expression of cDNA from the ApEGF gene, examined the transcriptional changes, and investigated the wound-healing effect of this protein in cells and rat epidermis. Primers were designed based on available sequence information related to the ApEGF gene in a public database, and part of the ApEGF sequence was obtained. The full-length cDNA sequence of ApEGF was obtained using inverse PCR. The gene sequence fragment of ApEGF was 666 bp in length, encoding 221 amino acids, with a predicted protein mass of 24.19 kD, an isoelectric point of 5.15, and no signal peptide sequence. Sequence homology analysis revealed 86.1% sequence homology with Bombyx mori, 92.7% with Manducal sexta, 92.6% with Trichoplusia ni, and 91.8% with Helicoverpa armigera. ApEGF was truncated and then subjected to prokaryotic expression, isolation, and purification. Truncated ApEGF was used for wound-healing experiments in vitro and in vivo. The results showed that after 48 h, transforming growth factor (TGF)-β1 had 187.32% cell growth effects, and the ApEGF group had 211.15% cell growth compared to the control group in vitro. In rat epidermis, truncated ApEGF showed a significantly better healing effect than the control. This result indicated that ApEGF, which exerted a direct wound-healing effect, could be used in wound-healing therapy.

This study reports the first complete mitochondrial genome of Antheraea pernyi Guérin-Méneville 1855 (Lepidoptera: Saturniidae) strain Dingzhou_1, a silkworm resource serving silk production in North Korea. The mitochondrial genome is circular with 15,573 bp in length encoding 37 typical mitochondrial genes (13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes). The 553-bp A + T-rich region harbors a repeat region composed of 6 ∼ 38 bp tandem repeat units, as found in other known inbred strains from Chinese populations. The phylogenetic analysis clustered Dingzhou_1 from North Korea together with Chinese Liaoning population, suggesting that oak silkworm in North Korea might be introduced from her neighbor China Liaoning.

The Antheraea Pernyi silk gland protein originates from natural organisms and synthesized by tussah silk glands and has widely potential biomaterial applications due to the superior biocompatibility. This study investigates the Antheraea Pernyi silk gland protein-based drug-loaded bio-hydrogels for bioengineered tissue fabricated by using an eco-friendly method without the harsh extracting process and the usage of toxic chemicals. The drug-loaded bio-hydrogels exhibited a porous structure and interconnected pore walls. The swelling ratio and water absorption of drug-loaded bio-hydrogels were, respectively, above 95% and 1.5 × 103%. The cumulative release of drug loaded hydrogels all reached more than 90% within 4 h, and this indicates the potential of drug-loaded hydrogels as future drug-carrying biomaterials. RSC96 Schwann cells cultured on drug-loaded hydrogels for 72 h under cell culture medium show no toxic effects and more pro-proliferative effects. The results suggest the suitability of drug-loaded bio-hydrogels as natural biopolymer for the potential in vitro RSC96 cell culture platform and other biomaterial applications.

In this paper, extracts from male zooid of Antheraea pernyi (EMZAP) were investigated for their antiobesity activity in C57BL/6 male mice. Mice were randomly divided into 4 groups and fed on basal control group diet (Control Group), high-fat diet (Model Group), high-fat diet containing high dose of EMZAP (High Group), and high-fat diet containing low dose of EMZAP (Low Group), respectively. The levels of serum lipid, antioxidant capacity, body weight, and adipose weight were measured. The levels of expression of genes involved in cholesterol metabolism were also determined by Real-Time PCR. The results showed that EMZAP could reduce body weight and epididymal adipose weight of mice on fed high-fat diet, and also decrease serum lipid levels in mice with induced obesity. Treatment with EMZAP also produced significant amelioration of lipid accumulation and improved the antioxidant capacity in the liver. EMZAP reduced the expression of HMG-CoA reductase (HMG-CoA-R) and increased the expression of cholesterol 7-alpha hydroxylase (CYP7A1) and LDL receptor (LDLR). But it has no obvious effect on the expression of LXR-. According to the above results, EMZAP had good anti-obesity attributes and improvement in conditions arising out of cholesterol accumulation. [ABSTRACT FROM AUTHOR]

The present study for the first time describes the complete mitochondrial (mt) genome of Antheraea pernyi Guérin-Méneville 1855 strain Luhong, a genetic lethal mutant exhibiting especially red skin color. The mt genome is 15,563 bp in length that is the smallest among the sequenced A. pernyi inbred strains. This genome displays an identical genomic component and gene order to other six known A. pernyi mt genomes. The mt genome-based phylogenetic analysis clustered Luhong with four strains exhibiting yellow skin color, consistent with the traditional view that all of them belonged to the yellow blood lineage.

Japanese giant silkworm (JGS), Caligula japonica Moore, is an emerging defoliator pest of forest and fruit trees in East Asia, causing severe economic losses. To develop a cost-effective biological control program against JGS, we used eggs of the Chinese oak silkworm (COS) Antheraea pernyi Guérin-Méneville as an alternative host to rear the most dominant JGS egg parasitoid Anastatus japonicus Ashmead. We compared the demographic parameters and total parasitism (killing) rates of A. japonicus parasitizing JGS and COS eggs using an age-stage, two-sex life table method. The results showed that A. japonicus performed differently on these two different hosts. Anastatus japonicus reared from COS eggs had a higher fecundity (369.7 eggs per female) and a longer oviposition period (35.9 days) on the COS than JGS eggs (180.9 eggs; 24.0 days). Consequently, A. japonicus parasitizing COS eggs had a higher intrinsic rate of increase (r = 0.1466 d−1), finite rate of increase (λ = 1.1579 d−1) and net reproductive rate (R0 = 284.9 offspring) than those parasitizing JGS eggs (r = 0.1419 d−1, λ = 1.1525 d−1, R0 = 150.0 offspring). The total net parasitism rate (the number of parasitized hosts in which the parasitoids successfully developed) of A. japonicus parasitizing COS eggs was 284.9, significantly higher than that of A. japonicus parasitizing JGS eggs (150.0), while the net non-effective parasitism rate (the number of parasitized hosts in which the parasitoids failed to develop) of the former (0.0) was significantly lower than that of the latter (9.6). These results suggest that A. japonicus can be efficiently reared on the alternative (or factitious) COS eggs, and the reared parasitoids have a high biological control potential against the target JGS.

The Chinese oak silkworm, Antheraea pernyi , has not only been semi-domesticated as an important economical insect but also used for genetic research. The female moths of A. pernyi employ a pheromone blend containing (E , Z)-6,11-hexadecadienal (E 6, Z 11-16:Ald), (E , Z)-6,11-hexadecadienyl acetate (E 6, Z 11-16:OAc), and (E , Z)-4,9-tetradecadienyl acetate (E 4, Z 9-14:OAc). While its biosynthesis pathway is largely unknown. By deep sequencing and de novo assembly of sex pheromone gland (PG) transcriptome, we identified 141 candidate genes that are putatively related to pheromone biosynthesis, degradation, and chemoreception in A. pernyi. Gene expression patterns and phylogenetic analysis revealed that two desaturases (AperDES1 and 2), two fatty acid reductase (AperFAR1 and 2), and three acetyltransferase genes (AperACT1 , 2 and 3) showed PG-biased or specific expression and were phylogenetically related to genes known to be involved in pheromone synthesis in other species. Furthermore, two carboxylesterases (AperCOE6 and 11) and two chemosensory protein (AperCSP1 and 6) were also expressed specifically or predominantly in the PGs, which might be related to sex pheromone degradation and transportation, respectively. Based on these results, the sex pheromone biosynthesis and metabolic pathway was proposed in A. pernyi. This study provides some crucial candidates for further functional elucidation, and may be used for interfering sexual communication in other Saturniidae pests. [ABSTRACT FROM AUTHOR]

Silk protein fibroin (SF)-based matrices from non-mulberry, and mulberry silkworms are used for different applications in regenerative medicine. Silk fiber spun by the wild non-mulberry silkworm Antheraea pernyi (Ap) is also a promising biomedical material, due to the presence of the inherent tripeptide sequence of Arginine-Glycine-Aspartic acid (RGD) on the protein fibroin sequences. However, SF derived from the Ap cocoons still lacks exploitation in the healthcare field due to its poor solubility in the conventional solvents. This work addresses the application of green chemistry principles, namely the use of ionic liquids (ILs, 1-butyl-imidazolium acetate) and renewable resources such as Antheraea pernyi silk fibroin (ApSF) and chitin (Ch), for the fabrication of sponges from the blends of ApSF and Ch (APC). The formation of β-sheet in different contents during ApSF/Ch/IL was acquired by exposing gels to methanol/water and ethanol/water. The sponges were then obtained by freeze-drying. This approach promotes the formation of both stable and ordered ApSF/Ch-based sponges. The developed sponges show the suitable porosity and interconnectivity, appreciable swelling degree, and tuneable viscoelastic compressive properties for tissue engineering applications. Collectively, the structural properties of these ApSF/Ch-based sponges make them promising candidates for biomedical applications, namely cartilage regeneration.

Antheraea pernyi is a semi‐domesticated lepidopteran insect species valuable to the silk industry, human health, and ecological tourism. Owing to its economic influence and developmental properties, it serves as an ideal model for investigating divergence of the Bombycoidea super family. However, studies on the karyotype evolution and functional genomics of A. pernyi are limited by scarce genomic resource. Here, we applied PacBio sequencing and chromosome structure capture technique to assemble the first high‐quality A. pernyi genome from a single male individual. The genome is 720.67 Mb long with 49 chromosomes and a 13.77‐Mb scaffold N50. Approximately 441.75 Mb, accounting for 60.74% of the genome, was identified as repeats. The genome comprises 21,431 protein‐coding genes, 85.22% of which were functionally annotated. Comparative genomics analysis suggested that A. pernyi diverged from its common ancestor with A. yamamai ~30.3 million years ago, and that chromosome fission contributed to the increased chromosome number. The genome assembled in this work will not only facilitate future research on A. pernyi and related species but also help to progress comparative genomics analyses in Lepidoptera. [ABSTRACT FROM AUTHOR]

BACKGROUND Trichogramma dendrolimi has been widely used in augmentative biocontrol of lepidopteran pests in China. In mass production of T. dendrolimi using Antheraea pernyi eggs as substitutive hosts, which are large in size, as clutch size is a parameter of importance to produce high quality parasitoids. Here, we aimed to determine the optimal clutch size for the bisexual Wolbachia‐uninfected line (TdB) and Wolbachia‐infected thelytokous line (TdT) of T. dendrolimi reared on A. pernyi eggs. RESULTS: A medium clutch size of 42.75 to 62.27 for TdB and 52.93 to 57.14 for TdT was optimal to maximize fitness‐correlated traits of parasitoid individual. The optimal clutch sizes with maximized parameters included adult emergence rate, adult body size, adult longevity, fecundity, and sum of fecundity of all females per brood were 58.31 (86.00%), 42.75 (231.11 μm), 50.92 (2.69 days), 62.27 (150.89 eggs), and 83.25 (7926.33 eggs) for TdB and 57.14 (94.54%), 52.93 (236.97 μm), 53.64 (2.62 days), 56.80 (161.01 eggs), and 70.10 (8579.71 eggs) for TdT. The TdT had a shorter adult longevity, longer development time, and higher adult emergence rate than did its non‐infected bisexual counterpart. CONCLUSION: A medium brood size in a A. pernyi egg host was optimal to produce offspring parasitoids with higher fitness parameters for both bisexual Wolbachia‐uninfected and thelytokous Wolbachia‐infected lines of T. dendrolimi. The determination of optimal clutch size for T. dendrolimi will provide the reference for the quality control of T. dendrolimi production and improvement of the field performance of the wasps. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND: Chouioia cunea Yang (Hymenoptera: Eulophidae) is a parasitic wasp and natural enemy of several lepidopteran pests during their pupal stage. The volatiles from pupae of three hosts, Hyphantria cunea (Arctiidae), Antheraea pernyi (Saturniidae) and Lymantria dispar (Erebidae), were analyzed and compared to elucidate the chemical cues used by C. cunea to locate its hosts. RESULTS: The attraction of C. cunea to H. cunea pupae has no obvious association with the types of plant leaves consumed by H. cunea before pupation. C. cunea exhibited the strongest attraction to the pupae of H. cunea, followed by those of A. pernyi and L. dispar based on behavioral experiments. Gas chromatography‐mass spectrometry and GC‐electroantennography (GC‐EAD) analyses showed that these three host pupae consisted of essentially the same active volatile components but at different relative amounts. Active components derived from these pupae by GC‐EAD were alkanes from C12 to C27, and C. cunea showed different levels of attraction to different single compounds. CONCLUSION: Host location by C. cunea primarily depends on common compounds emanating from the pupae of several host species. The relative amount of each component varies across host species, guiding host preferences by C. cunea. Optimal blends of several components were identified. Understanding the chemical cues used by C. cunea to locate its host could increase the possibility of developing attractants for parasitic wasps and subsequently increasing the parasitism rate of C. cunea on various hosts. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Chinese oak silkworm (Antheraea pernyi) and mulberry silkworm (Bombyx mori) are economically important insects used for silk production and food resource. Entomopathogenic nematodes (EPNs) from the families of Steinernematidae and Heterorhabditidae are beneficial organisms currently considered in biological control. In this paper, we evaluated survival of two silkworm species exposed to four Steinernema species which are widely applied in pest control. The results showed that among four Steinernema species, S. bicornutum and S. feltiae did not have an effect on the larval survival to the two silkworm species, whereas S. carpocapsae and S. glaseri did have an effect. Each Steinernema species poses no threat to hatchability of eggs, pupation rate, larval durations and cocoon shell ratio. [ABSTRACT FROM AUTHOR]

In insects, trehalose accumulation is associated with the insulin/insulin-like growth factor signalling (IIS) pathway. However, whether insulin-like peptide is involved in the regulation of the trehalose metabolism during diapause termination remains largely unknown. This study assessed whether insulin-like peptide (ApILP) enhances the trehalose catabolism in the pupae of Antheraeapernyi during their diapause termination process. Injection of 10 μg of bovine insulin triggered diapause termination and synchronous adult eclosion in diapausing pupae. Moreover, treatment with bovine insulin increased the expression of trehalase 1A (ApTre-1A) and trehalase 2 (ApTre-2), as well as the activity of soluble and membrane-bound trehalase, resulting in a decline in trehalose levels in the haemolymph. Silencing ApILP via RNA interference significantly suppressed the expression of ApTre-1A and ApTre-2, thus leading to an increase in the trehalose concentration during diapause termination. However, neither injection with bovine insulin nor ApILP knockdown directly affected trehalase 1B (ApTre-1B) expression. Moreover, overexpression of the transcription factor forkhead box O (ApFoxO) induced an increase in trehalose levels during diapause termination; however, depletion of ApFoxO accelerated the breakdown of trehalose in diapausing pupae by increasing the expression of ApTre-1A and ApTre-2. The results of this study help to understand the contributions of ApILP and ApFoxO to the trehalose metabolism during diapause termination.

Aprostocetus brevipedicellus, a eulophid gregarious egg parasitoid of lepidopterous pests, is a potential biological control agent for the control of many forest pests. A dominant factitious host, Antheraea pernyi, has been widely used for mass rearing several parasitoids in China. However, whether A. pernyi eggs are suitable for A. brevipedicellus rearing remains unclear. Here we evaluated A. brevipedicellus parasitism and fitness of their offspring on A. pernyi eggs with five different treatments, including manually-extracted, unfertilized and washed eggs (MUW), naturally-laid, unfertilized and washed eggs (NUW), naturally-laid, unfertilized, and unwashed (NUUW) eggs, naturally-laid, fertilized and washed eggs (NFW), and naturally-laid, fertilized and unwashed eggs (NFUW). The results showed that A. brevipedicellus could parasitize host eggs in all treatments but significantly preferred MUW eggs to other treatments. Moreover, A. brevipedicellus preferred unfertilized eggs to fertilized eggs and parasitized more washed eggs than unwashed. The pre-emergence time of parasitoid offspring emerging from fertilized eggs was shorter than that from unfertilized eggs. More parasitoid offspring emerged from unwashed eggs than that from washed eggs. The offspring emergence rate was high (>95%) and also female-biased (>85%) among all egg treatments. The egg load of female parasitoid offspring emerging from MUW and NUW eggs was 30–60% higher than the remaining treatments. Overall, MUW eggs of A. pernyi are the most suitable for the mass production of A. brevipedicellus.

The Chinese oak silkworm is commonly used in pupal diapause research. In this study, a long photoperiod was used to trigger pupal diapause termination. Genes encoding three hormones, namely prothoracicotropic hormone (PTTH), ecdysis triggering hormone (ETH), and eclosion hormone (EH), were studied. Additionally, ecdysteroids (mainly 20-hydroxyecdysone, 20E) were quantified by HPLC. Pupal diapause stage was determined by measuring respiratory intensity. The pupae enter a low metabolic rate, which starts approximately 1 month after pupal emergence. ApPTTH expression showed a small increase at 14 days and then a larger increase from 35 days under the long photoperiod treatment. A similar pattern was observed for the titer of 20E in the hemolymph. However, ApETH expression later increased under the long photoperiod treatment (42 days) just before eclosion. Moreover, ApEH expression increased from 21 to 35 days, and then decreased before ecdysis. These results suggest that hormone-related gene expression is closely related to pupal development. Our study lays a foundation for future diapause studies in A. pernyi.

Serpin is a broadly distributed superfamily of proteins that have a crucial role in regulating various immune reactions. Herein we identified a serpin-10 gene from Antheraea pernyi that encodes a 1557 amino acid residue protein with a predicted molecular weight of 58.76 kDa. Recombinant Apserpin-10 protein was expressed in a prokaryotic expression system (Escherichia coli) and the purified protein was used to prepare rabbit anti-Apserpin-10 polyclonal antibodies. Quantitative real-time polymerase chain reaction and western blot analysis indicate that Apserpin-10 was transcribed in all the tissues examined, including haemolymph, malpighian tubules, fat body, silk gland, integument and mid gut; the greatest expression level of Apserpin-10 was recorded in the fat body and haemocytes. The comparison of different developmental stages showed that Apserpin-10 transcript level was highest in 5th instar larvae, while the lowest expression was recorded at the egg stage. We also investigated the expression patterns of Apserpin-10 in fat body and haemocyte samples, following administration of heat-inactivated gram-positive bacteria (Micrococcus luteus), gram negative bacteria (Escherichia coli), a fungus (Beauveria bassiana) and virus (nuclear polyhedrosis virus, NPV). A substantial up-regulation of Apserpin-10 expression was recorded following pathogen challenge in both the tissues tested. Further the knock down of Apserpin-10 led to down regulation of antimicrobial peptide genes. Altogether, our results indicate that Apserpin-10 is involved in the innate immunity of A. pernyi.

Here, we report the complete mitochondrial (mt) genome of Antheraea pernyi Qing_6, an improved strain serving silk production and edible insect resource for 50 years in Northeast China. The circular mt genome spans 15,572 bp in length and contains 37 typical coding genes (13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes). Its A + T-rich region is 552 bp in size exhibiting identical sequence with the first modern improved strain Qinghuang_1. Comparison analysis identified only 12 variable sites (5 substitutions and 7 indels) between Qing_6 and Qinghuang_1. The phylogenetic analysis also clustered Qing_6 and Qinghuang_1 together first, which was in line with the breeding history of the two strains.

Four species of Anastatus Motschulsky (Hymenoptera, Eupelmidae, Eupelminae) are newly reported as egg parasitoids of the Japanese giant silkworm, Caligula japonica Moore and, as an alternate laboratory host, the Chinese oak silk moth, Antheraea pernyi (Guérin-Méneville) (Lepidoptera, Saturniidae) in China. The four species, A. fulloi Sheng & Wang, 1997, A. gansuensis Chen & Zang, sp. nov., A. japonicus Ashmead, 1904, and A. meilingensis Sheng, 1998, were reared initially from eggs of C. japonica collected in Gansu, Jilin and Liaoning provinces and subsequently cultured in the laboratory on eggs of A. pernyi. An illustrated key to differentiate females of the four species, and males of some of the species is provided. Key features are illustrated, both sexes of the new species are described, and diagnoses of females of the other species are given. [ABSTRACT FROM AUTHOR]

Trichogramma parasitoids are biological control agents of a large number of lepidopterous pests. Mass production of these Trichogramma parasitoids is carried out on different factitious host eggs where the cost for mass rearing is high and the production efficiency is low. Therefore, efficient means and techniques for mass production of these parasitoids are needed. Host eggs of Chinese oak silkworm, Antheraea pernyi, not only proved effective for the mass production of a single Trichogramma species but also showed great potential for simultaneously producing two different Trichogramma species through multiparasitism. Here, we evaluated the outcomes of multiparasitism between Trichogramma chilonis and T. leucaniae reared on the eggs of two factitious hosts, Antheraea pernyi and Corcyra cephalonica. Our study indicated that parental wasps of both Trichogramma species reared on A. pernyi performed outstandingly in all aspects of multiparasitism on A. pernyi eggs. In contrast, significantly low parasitism rates for parental wasps reared on C. cephalonica and subsequently low emergence rates for their offspring were recorded for multiparasitism on A. pernyi eggs. Parental wasps reared on different host eggs significantly affected the emerged offspring numbers for both Trichogramma species per A. pernyi egg. Significantly high numbers of offspring for specific species of Trichogramma emerged per A. pernyi egg when the parental wasps of that species were reared on A. pernyi eggs compared to the other species reared on C. cephalonica eggs. The present study concluded that rearing host species had a great impact on the performance of parental wasps in the multiparasitism of Trichogramma parasitoids on A. pernyi eggs and clearly confirmed that T. chilonis and T. leucaniae parasitoids can be massively produced on A. pernyi eggs through multiparasitism. Our results provide useful information about rearing hosts, which could provide two different Trichogramma species in the field at a time for the suppression of pest populations. [ABSTRACT FROM AUTHOR]

Highlights • The cuticle transcriptome profiles of Antheraea pernyi larvae between ApNPV-infected and control groups were compared. • The differentially expressed genes (DEGs) were analyzed by GO and KEGG analysis. • The DEGs related to chitin metabolism of Antheraea pernyi were characterized. Abstract Baculovirus causes liquefaction of insect cuticle to enhance the dissemination of progeny virions away from the host cadavers for increasing viral transmission rates. Antheraea pernyi nucleopolyhedrovirus (ApNPV) infects A. pernyi larvae with circular pus blotches formed in cuticle in the early stage of liquefaction. To investigate the formation mechanism of those pus blotches, the transcriptome profile changes of the cuticles between ApNPV-infected and non-infected A. pernyi larvae were analyzed using RNA-Seq. The transcriptome was de novo assembled using the Trinity platform. Comparison of gene expression levels revealed that a total of 2990 and 4427 unigenes were up- and down-regulated respectively in ApNPV-infected cuticle, of which 2620 and 1903 differentially expressed genes (DEGs) could be enriched in different GO terms and KEGG pathways. In this study, we focused on chitin metabolism related DEGs, and screened 10 genes involved in chitin synthesis and degradation with down-regulated trends, indicating that the chitin metabolism pathway was inhibited by ApNPV infection, which may promote liquefaction of A. pernyi cuticle. Besides, we also identified a large number of DEGs involved in immune related pathways via KEGG analysis, indicating that intense immune responses occurred in A. pernyi cuticle. Our research findings will serve as a basis for further researching the molecular mechanisms underlying cuticle liquefaction of A. pernyi induced by ApNPV infection. [ABSTRACT FROM AUTHOR]

Trichogramma parasitoids are important biological control agents for insect pest management. However, efficient means for mass production of Trichogramma parasitoids are needed, particularly for T. ostriniae, which often fail to form emergence holes on host eggs of Chinese oak silkworm, Antheraea pernyi, because of the hard chorion. In the present study, we evaluated the possibilities to enhance adult emergence of T. ostriniae by utilizing emergence holes made by T. dendrolimi during multiparasitism on host eggs of A. pernyi and other biological parameters such as pre-emergence time, parasitism rate, and emergence rate of the two parasitoids, which were also evaluated between the two parasitism regimes of multi- and monoparasitism. Our data showed that multiparasitism on host eggs of A. pernyi significantly facilitated the emergence of adult T. ostriniae. Generally, both Trichogramma species favored parasitizing A. pernyi eggs, with multiple parasitoid adults emerged per host egg. The overall performance of T. dendrolimi was similar between the two parasitism regimes, although a significantly higher number of unemerged adults were found in the multiparasitized eggs than in the monoparasitized. For T. ostriniae, significantly more adults emerged, and a higher emergence rate was recorded on host eggs multiparasitized with T. dendrolimi than that on monoparasitized. Furthermore, significantly fewer unemerged adults were found in multi- than monoparasitized host eggs. The results of this study provided useful information on the feasibility of mass production of T. ostriniae via multiparasitism with T. dendrolimi on large eggs of A. pernyi. [ABSTRACT FROM AUTHOR]

[Display omitted] • First 3D reconstruction of larval and adult brains of representatives of the Saturniidae family. • In both Saturniidae species the overall architecture of the brain is the same in larvae and adults. • Both Saturniidae species show significant sexual dimorphism in the size of the antennal lobes. • The structure of brain neuropils is virtually identical in Saturniidae and Sphingidae. • There are significant differences in the brain neuropiles architecture between moths and butterflies. We present a detailed analysis of the brain anatomy of two saturniid species, the cecropia silk moth, Hyalophora cecropia , and the Chinese oak silk moth, Antheraea pernyi , including 3D reconstructions of the major brain neuropils in the larva and in male and female adults. The 3D reconstructions, prepared from high-resolution optical sections, showed that the corresponding neuropils of these saturniid species are virtually identical. Similarities between the two species include a pronounced sexual dimorphism in the adults in the form of a male-specific assembly of markedly enlarged glomeruli forming the so-called macroglomerular complex. From the reports published to date, it can be concluded that the neuropil architecture of saturniids resembles that of other nocturnal moths, including the sibling family Sphingidae. In addition, compared with previous anatomical data on diurnal lepidopteran species, significant differences were observed in the two saturniid species, which include the thickness of the Y-tract of the mushroom body, the size of the main neuropils of the optic lobes, and the sexual dimorphisms of the antennal lobes. [ABSTRACT FROM AUTHOR]

Insect pheromone biosynthesis activating neuropeptide (PBAN) controls the synthesis and actuating of sex pheromones of female adult. In the current examination, the full-length cDNA encoding the PBAN receptor was cloned from the pheromone gland (PG) of Antheraea pernyi (AntpePBANR). The AntpePBANR displayed the characteristic seven transmembrane areas of the G protein-coupled receptor (GPCR) and was closely related to the PBANR from Bombyx mori and Manduca sexta in the phylogenetic tree. The AntpePBANR expressed in mammalian cell lines were enacted by AntpePBAN in a concentration-dependent manner. AntpePBANR activation resulted in the calcium mobilization but did not activate the cAMP elevation pathway. Cells expressing AntpePBANR were profoundly responsive to Antpe-γ-SGNP (suboesophageal ganglion neuropeptides) and Antpe-DH (diapause hormone), different individuals from FXPRLamide (X = T, S or V) family in A . pernyi . Deletion of residues in the C-terminal hexapeptide (FSPRLamide) proved that P, R and L played the key parts in initiating the AntpePBANR, the amination to the last C terminal residues which can also likewise impact the activation of AntpePBAN receptor altogether. The mRNA of the AntpePBANR gene demonstrated the most noteworthy transcript levels in pheromone gland followed by fat body. [ABSTRACT FROM AUTHOR]