Antheraea castanea Jordan, 1910, the neglected "pseudomuga" silkmoth (Lepidoptera, Saturniidae)

Antheraea castanea Jordan, 1910, the neglected "pseudomuga" silkmoth (Lepidoptera, Saturniidae) Zhengyang Liu1, Changxiong Hu2, Muyang He3 1 Zhangdian District, Zibo, Shandong Province 255000, China 2 Sericultural and Apicultural Research Institute, Yunnan Academy of Agricultural Sciences, Mengzi, Yunnan Province 661101, China 3 Xiangximeilin, Anyuan District, Pingxiang, Jiangxi Province 337000, China https://zoobank.org/75BD9E13-71DD-480E-922E-D41E021A9DD2 Corresponding author: Zhengyang Liu ([email protected]) Academic editor: Matthias Seidel ♦ Received 4 March 2025 ♦ Accepted 9 October 2025 ♦ Published 4 November 2025 Abstract This study reports the first complete life history of Antheraea castanea Jordan, 1910. Samples collected from the southeastern borders of Yunnan and Tibet were reared on specific species within the family Lauraceae, confirming that A. castanea is univoltine in captivity. The complete mitochondrial genome sequences of A. castanea and Antheraea youngi Watson, 1915, both belonging to the subgenus Antheraeopsis Wood-Mason, 1886, are provided. Genomic and morphological evidence demonstrates that A. castanea is the sister group to all other Antheraeopsis spp. This finding strongly supports the hypothesis that this subgenus originated in the southeastern regions of the Himalayas, making A. castanea a key taxon for understanding the evolutionary history of the genus Antheraea Hübner, 1819. Given its long-standing neglect in sericulture, we recommend increased attention to A. castanea in future studies— particularly to prevent misidentification with the muga silkmoth, Antheraea assamensis (Helfer, 1837), which shares similar habitats. Key Words Antheraeopsis, complete mitochondrial genome, India, Lauraceae, life history, morphology, muga, phylogeny, sericulture, Tibet, wild silkmoth, Yunnan, zoogeography Introduction The famous muga silkmoth, Antheraea assamensis (Helfer, 1837), is one of the most economically important species in Northeast India (e.g., Peigler 1993, 2020). The sericulture of this species in Assam was reported in early literature (e.g., Hugon 1837), and it remains a current hot topic in saturniid studies. As one of the three clades constituting the genus Antheraea Hübner, 1819 (Nässig 1991), the muga subgenus Antheraeopsis Wood-Mason, 1886, is restricted to subtropical and tropical Asia. Kitching et al. (2018) listed 12 currently accepted species. Based on their type localities, these include Sichuanese Antheraea chengtuana Watson, 1923; Taiwanese Antheraea formosana Sonan, 1937; Andamanese Antheraea rudloffi Brechlin, 2002; Sumatran Antheraea brunnea van Eecke, 1921; Bornean Antheraea youngi Watson, 1915; Javan Antheraea rubiginea Toxopeus, 1940; Palawan Antheraea sahi Nässig & Treadaway, 1998; and Philippine Antheraea paniki Nässig & Treadaway, 1998. However, Antheraea inthanonensis Paukstadt & Paukstadt, 2013, and Antheraea tenasserimensis Paukstadt & Paukstadt, 2013, from Thailand are very close to A. assamensis in terms of morphology and barcoding—we believe they are better treated as different subspecies or even synonyms. Another species, originally collected in the Meghalayan Khasi Hills, was named Antheraea castanea Jordan, 1910, but it has not been discussed by Indian authors except for Gupta (2000). Naumann et al. (2008) confirmed that Antheraea mezops Bryk, 1944, which is typically from Burmese Kambaiti, is a junior synonym of A. castanea. All Chinese specimens in our hands were captured only in the rain-rich broadleaf forests at elevations of ca. 1200–2200 m in Mêdog, Tibet (Fig. 1B), Dtsch. Entomol. Z. 72 (2) 2025, 303–315|DOI 10.3897/dez.72.151952 Copyright Zhengyang Liu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. dez.pensoft.net Zhengyang Liu et al.: Life history and phylogeny of Antheraea castanea304 as well as in the Nujiang, Baoshan (Figs 1A, 4G), Dehong, Pu’er, and Honghe regions of Yunnan. It has not been found in Xishuangbanna, which borders Laos and has relatively low altitudes. This aligns with the opinion of Paukstadt and Paukstadt (2008): the samples from Laos identified as A. castanea in Brosch et al. (1999) were determined incorrectly. The giant moths of A. castanea are beautifully castaneous, as suggested by the etymology of its specific name. Our observations show that these adults emerge from May to August in the wilds of Tibet and Yunnan, which corresponds with the Burmese records provided by Racheli (2008), and are possibly univoltine in nature (see also Sections 3 and 4 of Results). Recently, material from the border between Vietnam and Yunnan has been correctly identified by local entomologists (e.g., Lien et al. 2014; Wu 2017: 150–151). In summary, A. castanea should be seen as a montane and summer-flying species endemic from northeastern India (and southeastern Tibet) to northern Myanmar, through western and southern Yunnan, extending to northwestern Vietnam but seemingly excluding Laos. Irungbam and Irungbam (2019) mentioned a Bhutanese distribution of A. castanea but provided no supporting specimens. However, due to the similarity between adults and partial habitat overlap, A. castanea was previously misidentified as a subspecies or synonym of A. assamensis (e.g., Bryk 1944; Holloway 1987; d’Abrera 2012: 126–127; Kumar et al. 2016). Alternatively, specimens of the former were erroneously attributed to the latter (e.g., Seitz 1926–1928: 55B; Villiard 1969: 78; Yang et al. 2015: Figure 1. Living adults of Antheraea castanea; dates indicate photography dates. A. ♂, Gaoligong Mountains, Baoshan, Yunnan, 2214 m, 22 June 2025 (the moth was photographed locally); B. ♀ No. 6, Mêdog County, Nyingchi, Tibet, 2182 m, 06 July 2025 (the moth was captured locally and sent to Kunming, Yunnan, for photography). Scale bars: 3 cm. Dtsch. Entomol. Z. 72 (2) 2025, 303–315 dez.pensoft.net 305 533; Yi et al. 2015: 35). Furthermore, Paukstadt et al. (1998) corrected the erroneous combination “A. castanea youngi,” which had previously been misapplied to the Thai A. assamensis (e.g., Nässig et al. 1996; Lampe 2010: 274), as stated by Peigler (2010). Compared to other Antheraeopsis populations, several characteristics of A. castanea male genitalia are autapomorphic (Paukstadt et al. 1999), in addition to its uniquely pointed forewing apex (Bouvier 1936: 161). It is possible that A. castanea is the sister group to all other species within Antheraeopsis. Since past studies based on adult specimens and shorter COI sequences have not addressed this issue, dedicated research on the previously unknown preimaginals of A. castanea would help to clarify its phylogenetic position. Additionally, this would allow higher-quality genomes to be incorporated into phylogenetic analyses. Materials and methods Collection and rearing This paper utilizes the eggs from a total of six wild-caught ♀♀ A. castanea for subsequent life history studies. Data for the moths are as follows: No. 1, Lüchun County, Honghe, Yunnan, 1288 m, 18 July 2023; No. 2, same location, 19 July 2023; No. 3, Jinping County, Honghe, Yunnan, 1387 m, 19 June 2024; No. 4, same location, 29 June 2024; No. 5, same location, 2 July 2024; No. 6, Mêdog County, Nyingchi, Tibet, 2182 m, 27 June 2025. Among them, the eggs of ♀♀ Nos. 1–4 and 6 were reared by Liu ZY in Wuhua District, Kunming, Yunnan (1920 m); ♀♀ Nos. 1–5 were reared by Hu CX in Mengzi, Honghe, Yunnan (1285 m); and ♀ No. 3 was reared by He MY in Anyuan District, Pingxiang, Jiangxi (112 m). The samples used for morphological description are those of Liu ZY, with the following terminology abbreviations: L1–5 = 1st–5th larval instars; T1–3 = 1st–3rd thoracic segments; A1–10 = 1st–10th abdominal segments. The dimensional data described in the Results are based on measurements of single samples (n = 1). The general equipment used includes a vernier caliper INSIZE 1108-150C 0–150 mm/0.01 mm (± 0.02 mm) (general lengths); a thermohygrometer BENETECH GM1365 (± 2 RH%; ± 0.3 °C) (humidity and temperatures); a NIKON D5500 with a LAOWA 60 mm f/2.8–22 lens (Figs 1, 3, 4A–F, 5); and a SIGMA 10–20 mm f/4–5.6 lens (Fig. 4G). One unhatched A. castanea ovum (surface-dried and sputter-coated) was used for scanning electron microscope (SEM) imaging with a ZEISS GEMINISEM 360 (Fig. 2). Molecular sequencing and phylogenetic analysis One contribution of this study is the provision of two new complete mitochondrial genome (CMG) sequences. The tissue was ground in liquid nitrogen, followed by DNA extraction using 1 ml of preheated (65 °C) CTAB buffer with 2% β-mercaptoethanol and 50 µl of proteinase K (20 mg/ml). DNA was purified by chloroform–isoamyl alcohol (24:1) extraction, isopropanol precipitation, and RNase A treatment. Nucleic acid concentration was measured using INVITROGEN QUBIT 3.0 with the QUBIT dsDNA HS Assay Kit, and integrity was assessed by 1% agarose gel electrophoresis. For library preparation (using the VAHTS Universal Plus DNA Library Prep Kit for Illumina-ND617), we followed the ILLUMINA DNA Prep Protocol (#1000000025416), which included enzymatic fragmentation, end repair with 3′ adenylation, adapter ligation, PCR amplification, and product purification using VAZYME DNA Clean Magnetic Beads. Paired-end sequencing was carried out on an ILLUMINA NOVASEQ 6000 platform using libraries that passed quality control. The samples used are as follows: • Antheraea castanea: An L1 larva from ♀ No. 3 (see above), hatched from ovum on 2 July 2024. It was killed on 5 July 2024 and preserved in 95% (± 5%) ethanol at −18 °C until 13 January 2025 for sequencing. • Antheraea youngi: A ♂ adult from Trus Madi Entomology Camp, Keningau, Sabah, Malaysia, 1183 m, captured and killed on 6 February 2023, then stored dry in a triangular envelope at room temperature. Thoracic muscles were extracted for sequencing on 13 January 2025. The CMG assemblies were performed using SPADES 3.15.4 (Prjibelski et al. 2020), then annotated with MITOS2 (Donath et al. 2019) and manually curated for accuracy. The corresponding high-throughput files are accessible in NCBI BioProject PRJNA905660. OGDRAW (Greiner et al. 2019) was used to draw the linear map, followed by manual visual optimization with AFFINITY PHOTO 2 (Fig. 6). We followed the suggestion of Liu (2024) to use CMGs rather than the 13 protein-coding genes (PCGs) to construct the first phylogenetic tree (Suppl. material 1: tree S1). In addition to our new sequences, this dataset includes 39 other species of Saturniidae, with two taxa from Bombycidae and one from Lasiocampidae selected as outgroups (Suppl. material 1: table S1). Sequence alignment was performed using MAFFT 7 (Katoh et al. 2019) with default settings, and phylogenetic inference was conducted using IQ-TREE 2 (Minh et al. 2020) under the best-fit model GTR + F + I + R5, chosen according to BIC (Kalyaanamoorthy et al. 2017), with ultrafast bootstrap (1,000 replications) (Hoang et al. 2018). For the second tree (Suppl. material 1: tree S2), we selected COI barcodes for 10 Antheraeopsis spp. (based on the complete list of 12 species provided by Kitching et al. 2018, excluding the uncertain A. inthanonensis and A. tenasserimensis). Three to five sequences for each species (from or close to the type locality) were downloaded from BOLD Systems 4 (v4.boldsystems.org) (Suppl. material 1: table S2) and added to the above CMG dataset. The alignment and tree generation were performed using the same software and parameters. The resulting complete topologies of the two maximum likelihood (ML) trees were preliminarily visualized with ITOL 6 (Letunic and Bork 2021), followed by manual color and layout design using AFFINITY PHOTO 2 (Fig. 7). dez.pensoft.net Zhengyang Liu et al.: Life history and phylogeny of Antheraea castanea306 To improve clarity, we created an approximate current distribution map for Antheraeopsis spp. (Fig. 7). It is primarily based on logical inferences from our phylogenetic analysis, supplemented by specimens from China, Vietnam, and Borneo in our collection. Additionally, records from all available literature listed in the References were consulted, with preference given to those from dedicated taxonomic studies (e.g., Brechlin 2001; Paukstadt and Paukstadt 2008). In this work, we do not comment on the taxonomic handling of other Antheraeopsis taxa by Kitching et al. (2018) aside from A. castanea. Results 1. Immature stages of A. castanea from southeastern Yunnan (based on offspring of ♀ No. 3) 1.1. Ovum (Figs 2, 3A): The overall shape is tri-axial ellipsoid (2.65*2.22*1.68 mm), with a grayish chorion covered by dark brown glue. The micropylar rosette is composed of polygonal imprints left by follicle cells. Crowned aeropyles are dispersed across the external surface, except in and immediately around the micropylar zone. 1.2. L1 (Fig. 3B, C): The shiny red-brown head capsule is 1.28 mm wide, with long white bristles anteriorly. The cervacoria is gray. The ground color from T1 to A10 is yellow, vivid dorsally and pale ventrally. Each of T2–A8 has two black transverse stripes, one anterior and one posterior, to the segmental transverse row of subdorsal and dorsal scoli. Additionally, a black stripe decorates each segmental junction from T1 to A8. The dorsal midline T2–A8 is dark in color. The prothoracic shield is black, with forward-pointing and curved primary setae at the anteromarginal position (borne on the tactile dorsal and subdorsal scoli). Most other scolus bases are the same yellowish color as the surrounding integument; they bear gray, slightly curved primary setae. However, the lateral and subdorsal scoli of T1– A1, the subdorsal scoli of A9, and the dorsal scoli of A10 show more melanin at their bases and hairs, with the melanin extending into the surrounding areas. A pair of dorsal scoli are fused medially on A8. The sclerites of the legs T1–3 are smooth and dark brown, while the prolegs A3–6 are pale yellow, the same color as the venter. The lateral plate of proleg A10 and the postcentral area of the anal shield are black. 1.3. L2 (Fig. 3D, E): The width of the head capsule is 2.12 mm, and its color is the same as in L1, but the cervacoria has changed to light ochre. The integument is generally yellowish-green, and the black transverse stripes present in the previous instar are now absent. The dorsal midline from T2 to A8 is dark green. In the lateral view, the subdorsal scoli of A1–9 are connected by a horizontal olive-green stripe. In some individuals, a similar but very faint stripe connects the dorsal scoli from T2 to A8, though it is absent in others. The black prothoracic shield is divided by a light yellow midline. All primary setae of non-(sub)ventral scoli are black, with the longest ones appearing on the tactile dorsal and subdorsal scoli of T1. Additionally, all lateral, subdorsal, and dorsal scoli have a bluish-purple base. The lateroproximal area of each dorsal scolus from T2 to A9 displays a metallic silvery zone, though it has not fully developed yet. All spiracles are brown in color but paler on A8. The brown legs of T1–3 are lighter than in L1, and a subcircular black spot has developed on each proleg A3–6. The plantar lateral surfaces are light brown. For the late period, its greenish hue from T1 to A10 becomes more pronounced. The bluish-purple warts appear more vivid, with enhanced metallic silver zones. A supraspiracular yellow band begins to develop, extending from A1 to A10. Each segment from A2 to A7 is adorned with an oblique dark green subspiracular stripe. 1.4. L3 (Fig. 3F, G): The head capsule measures 3.69 mm in width, with coloration similar to L2. The previously distinct dark dorsal midline observed during L1–2 has nearly disappeared. The supraspiracular yellow band present in L2 becomes more conspicuous, while most other integumentary areas transition to green. All non- (sub)ventral scolus bases turn pinkish-purple except for the persistently blue dorsal scoli of A10. The dorsal silvery spots become more lustrous. The proximal areas of the coxae T1–3 and the lateral integument of T1 exhibit brighter yellowish tones. Several black dots develop on the lateral areas of prolegs A3–6, each bearing a seta. The lateral plate of proleg A10 appears subtriangular, yellow superiorly and black inferiorly, surrounded by a light brown fleshy “ring”. The postcentral black patch on the anal shield shrinks into a “V-shape”, flanked by brown fleshy margins. A transverse row of yellow hairs appearing on the anterior region of each A1–8. Short and crossed white setae emerge at the dorsal junctions of A2/A3, A3/A4, A4/A5, A5/A6, and A6/A7. All spiracles except the white one on A8 turn black, and their inferior oblique stripes (visible only on A2–7) become more distinct compared to L2. 1.5. L4 (Fig. 3H): Despite little change in coloration from the previous instar, the head capsule width increased to 5.23 mm. The cervacoria is pale wine-colored. The paired black spots on the prothoracic shield during L2–3 completely disappear, replaced by bright yellow-green pigmentation that intensifies along the anterior margin of T1 and on the coxae T1–3. The supraspiracular yellow band becomes strikingly vivid, edged with light brown from A3 to A9 (increasingly prominent posteriorly, but not visible on A3–6 in some individuals). The subspiracular oblique stripes present in L2–3 are very inconspicuous or even disappear. All lateral, subdorsal, and dorsal scoli develop mulberry-colored bases except those on T1, which appear light ochre. The short and crossed white setae Dtsch. Entomol. Z. 72 (2) 2025, 303–315 dez.pensoft.net 307 observed in L3 now additionally appear at the A1/A2 junction, while the transverse yellow setal rows on the anterior zones of A1–8 become more developed, with clubbed tips. The pattern on A10 resembles that of L4, but the lateral plate turns completely green, with a darker peripheral “ring”. The “V-shaped” postcentral black spot on the anal shield splits centrally into two parts, fading from black to brown, with its central area replaced by bright green. 1.6. L5 (Fig. 3I–R): This is the mature instar, with a head capsule 7.57 mm wide. The overall coloration of the head capsule is pale brownish-red, with dark brown processes on the lateral areas. While superficially similar to L4, several distinct morphological changes are evident. The overall green integument has become lighter in the dorsal area while simultaneously darkening ventrally, resulting in a more pronounced countershading effect. All scoli that possessed a mulberry-colored base in the previous instar have now shifted to a vivid purple. Furthermore, the warts T1, previously light ochre during L4, are now a distinct lemon-yellow, and this yellow pigmentation is intensified across the entire anterior region of this segment—including the coxae but excluding the cervacoria—giving it a brighter and more vivid appearance. Notably, the majority of the yellow setae located on the anterior zones of A1–8, which were described in L4 as “having clubbed tips,” have now reverted to pointed tips. 1.7. Pupa (Fig. 4B–F): The pupal case is dark brown, except for a translucent ‘window’ between the compound eyes. The medial margins of the antennae do not meet along the ventral midline, and both the maxillae and the legs T1–2 are visible. Spiracle T1 appears as a narrow gap at the boundary between T1/T2; the spiracles A2–7 are well developed, but the spiracle A8 is likely a remnant. A pair of forewing tubercles is located on the dorsolateral regions of T2. The male genital pore appears as a navel-like scar on the midventral A9. The terminal A10 bears pointed cremaster hooks. 1.8. Cocoon (Fig. 4A): The freshly spun cocoons appear white in a relatively dry environment (ca. 50–70% RH), but after full oxidation (100% RH, 48 h), they turn light brown. The upper terminal end of the cocoon features a peduncle that wraps around the host plant, with the pupal head oriented upward and the exit side completely sealed. Cocoons are enclosed by surrounding leaves for protection. 2. Immature stages of A. castanea from southeastern Tibet (based on offspring of ♀ No. 6) Although SEM observation was not conducted, the external morphology, size, and coloration of the eggs are nearly identical to those of the specimens from Yunnan (see also Section 1.1). The L1–3 caterpillars are also generally consistent with the descriptions provided in Sections 1.2–1.4. However, several notable differences were observed: in the Tibetan population, all bluish-purple scolus bases—which are present in Yunnan L2 larvae—are bright aquamarine. Except on T1, these warts exhibit a distinctive yellow upper portion and a pinkish lower portion throughout L3–5. Another conspicuous distinction is the presence of more or less shiny, clubbed setae on all major scoli in L4–5 (Fig. 5A, B), a feature not observed in Yunnan larvae. Furthermore, the dorsal yellow hairs with clubbed tips, which were documented in Yunnan L4 larvae, are consistently present in both L4 and L5 of the Tibetan lineage. The larvae from Yunnan exhibit a darker appearance in the head capsule and legs T1–3 during L2–5 compared to those from Tibet. Furthermore, the brownish areas on A10 in L4–5 are also darker in the Yunnan population than in the Tibetan one (Fig. 5C, D) (see also Sections 1.5 and 1.6). The pupae and cocoons both conform to the descriptions provided in Sections 1.7 and 1.8. 3. Rearing report of A. castanea from southeastern Yunnan (based on offspring of ♀ No. 3) During the summer rearing of 2023, all L1 larvae of Liu ZY perished within one week after feeding on Camphora officinarum (Lauraceae) and Cinnamomum burmannii (Lauraceae). In contrast, Hu CX successfully reared a few individuals to L2 using the latter plant but did not continue observations. In the summer of 2024, the three authors re-evaluated these two plants, and all tested larvae once again died during L1. Liu ZY subsequently offered Quercus yunnanensis (Fagaceae), Alnus nepalensis (Betulaceae), and Liquidambar formosana (Altingiaceae) to 21 newly hatched L1 individuals, all of which completely rejected these Figure 2. Chorion of Antheraea castanea, SEM. A. The anterior pole, whose central area is the micropylar zone; B. Micropylar rosette; C. Aeropyle crowns. Scale bars: 100 μm (A); 20 μm (B); 10 μm (C). dez.pensoft.net Zhengyang Liu et al.: Life history and phylogeny of Antheraea castanea308 Figure 3. Ova and L1–5 of Antheraea castanea from southeastern Yunnan. A. Ova; B, C, E. On host plant Litsea populifolia; D, F–R, R. On host plant Camphora septentrionale; B. L1, lateral view; C. L1, dorsal view; D. L2, lateral view; E. L2, dorsal view; F. L3, lateral view; G. L3, head and T1–3, anterolateral view; H. L4, lateral view; I. L5, lateral view; J. L5, dorsal view; K. L5, subdorsal scolus of A2, apicolateral view; L. L5, dorsal scolus of A2, apicolateral view; M. L5, dorsal scoli of A8 (medially fused), apical view; N. L5, leg T3, lateral view; O. L5, head and T1–2, anterolateral view; P. L5, A10, dorsal view; Q. L5, A10, lateral view; R. L5, spinning the external part [floss] of cocoon, dorsal view. Scale bars: 1 mm (K); 2 mm (L, M); 3 mm (A, N); 1 cm (D, E); 5 mm (B, C, G, O–Q); 1.5 cm (F, H, I, J, R). Dtsch. Entomol. Z. 72 (2) 2025, 303–315 dez.pensoft.net 309 options. Ultimately, after accepting Litsea populifolia (Lauraceae) and Camphora septentrionale (Lauraceae) (rearing under conditions of 16.5–25.8 °C with ca. 70.6– 90.4% RH), nine individuals successfully spun cocoons. However, three of these died during the pre-pupation, while the remaining six pupae are all male. L1 caterpillars live independently on the undersides of leaves without integumentary contact with others, though 2–4 individuals may occasionally be found on the same leaf. When at rest, they typically assume a “J”- shaped posture. During L2–5, larvae are still generally solitary, residing either on the undersides of leaves or at the branches. As with most saturniids, supplementary water is essential for larval development. The larvae of L4–5 usually detach their legs T1–3 (sometimes including prolegs A3–4) from the vegetation, and during L2–5 they were consistently observed orienting their heads toward the side with higher illuminance. After feeding ended [liquid defecation], larvae all spun cocoons on host plants. The scoli of the whole larval stage have no visible exocrine secretion, without irritation to human skin. When the mature larvae are attacked, they will Figure 4. Cocoon and pupa of Antheraea castanea from southeastern Yunnan. A. Cocoon, spun and stored in a dry environment, lateral view; a: peduncle; b: the exit side; B–F. Pupa ♂; B. a: lateral view; b: ventral view; c: dorsal view; C. Head and T1–2, ventrolateral view; D. T1–2, dorsolateral view; a: spiracle T1; b: forewing tubercle; E. ventral view; a–c: A8–10 (the genital pore is located at the center of A9); F. Cremaster on the tip of A10, dorsal view; G. The habitat in Gaoligong Mountains, Baoshan, Yunnan Province, China, 2214 m, 24 ♂♂ were collected here on 21 June 2024 and 21–23 June 2025 by Liu ZY. Scale bars: 1 mm (F); 1.5 mm (E); 3 mm (C. D); 8 mm (B); 1 cm (A). dez.pensoft.net Zhengyang Liu et al.: Life history and phylogeny of Antheraea castanea310 shake T1–A3 from side to side, sometimes clicking the mouthparts to make noise. The developmental calendar is as follows (1 ♂, fed on C. septentrionale in 2024): 20 June, oviposited; 01 July, hatched into L1; 06 July, 1st pre-ecdysis; 07 July, molted into L2; 12 July, 2nd pre-ecdysis; 13 July, molted into L3; 17 July, 3rd pre-ecdysis; 18 July, molted into L4; 25 July, 4th pre-ecdysis; 27 July, molted into L5; 12 August, feeding ended and spun cocoon. On 28 May 2025, the moth emerged from its cocoon. 4. Rearing report of A. castanea from southeastern Tibet (based on offspring of ♀ No. 6) Based on the rearing experience in 2023–2024 (see also Section 3), during the summer of 2025, a total of 99 L1 larvae (from 137 eggs) were reared on C. septentrionale and Litsea rubescens (the only available L. populifolia had died and was therefore unusable), under conditions of 17.8–26.4 °C with ca. 66.3–87.4% RH. The latter host was more readily accepted by newly hatched caterpillars than the former. Compared with the L1 group reared on L. rubescens, those provided with C. septentrionale exhibited higher mortality and slower developmental progression, invariably failing to reach the L2. Therefore, all surviving larvae were ultimately reared on L. rubescens. Ultimately, seven mature larvae spun cocoons directly on this host plant, whereas the remainder left the vegetation, yielding a total of 35 cocoons. The period from initial oviposition to the spinning of the last cocoon extended from 27 June to 24 August. As of 19 September, no adult emergence had been recorded. Other biological traits observed during the larval stage were consistent with the corresponding descriptions provided in Section 3. 5. Phylogenetic Analysis on A. castanea and Antheraeopsis The CMG sequence lengths are 15,325 bp for A. castanea (GenBank accession number: PV136007) and 15,307 bp for A. youngi (GenBank accession number: PV136008) (Fig. 6). In the CMG-based phylogeny, all Antheraeopsis nodes received maximal support, whereas certain nodes in the CMG + COI topology showed lower support (Fig. 7). The two results form a single topology, indicating that the subgenus Antheraeopsis is composed of three major species groups. The CMG + COI tree shows a monophyletic group of four species [((A. assamensis + A. rudloffi) + A. chengtuana) + A. formosana] is distributed across the mainland of Southeast Asia and its northern tropical and subtropical territories (the “cool colors” in Fig. 7), i.e., the assamensis-group. Meanwhile, another lineage occupies Sundaland and the Philippines (the “warm colors” in Fig. 7), known as Figure 5. Mature larvae of Antheraea castanea from southeastern Tibet, on host plant Litsea rubescens. A. L5, lateral view; B. L5, dorsal scolus of A4, lateral view; C. L5, head and T1–3, anterolateral view; D. L5, A10, dorsolateral view; Scale bars: 2 mm (B); 5 mm (C, D); 1.5 cm (A). Figure 6. Linear map of the CMGs of Antheraea castanea (top) and Antheraea youngi (bottom). Dtsch. Entomol. Z. 72 (2) 2025, 303–315 dez.pensoft.net 311 the youngi-group, which contains five species [((A. paniki + A. sahi) + (A. youngi + A. brunnea)) + A. rubiginea]. A. castanea is the sister taxon to these two clades. Discussion Although the caterpillars from Honghe, Yunnan, and Mêdog, Tibet, exhibit some morphological differences, we currently do not propose to treat them as separate species—specifically, we refrain from resurrecting the name A. mezops for the former population or naming the latter as a new species. This decision is based on several factors: no life-history data are available from Meghalaya, western Yunnan, or northern Myanmar, and the genitalia of the Tibetan moths require further study, as no males have yet been obtained from field collection or rearing experiments. Moreover, even if the two were to be classified as distinct subspecies or species, they would still represent the closest known sister lineages within the subgenus Antheraeopsis, and these differences are not supported by reliable diagnostic characters in the imaginal external morphology, at least in females. Technically, any potential future taxonomic revisions would not affect the current discussion, which treats material from Yunnan and Tibet as a monophyletic group under the name A. castanea. Regier et al. (2005) described the eggshell of A. rubiginea (originally as “A. youngi from Java,” then corrected by Paukstadt and Paukstadt (2010)) as “the aeropyle crowns were uniformly distributed across the eggshell except immediately surrounding the region of the micropyle at the anterior pole.” Kumar and Kamble (2008) stated that “all the aeropyles of A. assamensis were covered with a cupshaped structure, and the terminals of this structure have many finger-like projections.” Our observations on A. castanea confirm that its aeropyle crown distribution pattern aligns with those of the two aforementioned species. Indian authors have published many morphological studies on the life history of A. assamensis (e.g., Jolly et al. 1979: 122–126; Goswami and Singh 2012; Kakati et al. 2012), while Lampe (2010: 274) and Wu (2017: 135–144) have illustrated the immature stages of the Thai and Chinese populations, respectively. Recently, Veenakumari et al. (2011) found some wild larvae of A. rudloffi from the southern Andaman. We have reared materials from Yunnan and Hainan, which we temporarily refer to as A. assamensis, as their larvae appear nearly indistinguishable from the caterpillars of A. chengtuana from Ya’an, Sichuan, and A. assamensis from Mêdog, Tibet (reared by Liu ZY in 2022 and 2025, respectively). The preimaginal A. formosana from Taiwan are also documented in several works (e.g., Lin et al. 1993; Wang 1994: 51–57; Wang and Heppner 1994; Peigler and Wang 1996: 240–245). Paukstadt and Paukstadt (2001) provided a complete life cycle of the Javanese A. rubiginea (originally as “A. youngi,” corrected by Paukstadt and Paukstadt (2010)). Additionally, van Eecke (1929) figured a mature larva of A. brunnea from Sumatra and provided a brief description. In all the compared specimens, L1 consistently exhibited a shiny black or blackish-brown head capsule, yellow dorsal coloration with black transverse stripes on T1, and a lateral black spot at the base of each proleg on A3–6. Despite variations in dorsal scolus coloration (ranging from black to light gray), these larvae are macroscopically indistinguishable. In comparison, A. castanea has a red-brown head capsule with an almost entirely black dorsum T1 and no black markings on the prolegs A3–6. Moreover, in L2–3 of Antheraeopsis, as known in the past, a continuous dark green stripe runs along each side (divided along the dorsal and ventral midlines), connecting the dorsal scoli from T2 to A8. Nässig (1991) identified this as a subgeneric synapomorphy; however, in A. castanea, it appears indistinct. For L4–5, morphological features that could identify specific populations are no longer discernible except for A. castanea from Tibet, which has characteristic clubbed setae. However, we currently know that the “yellow-green lateral plate of proleg A10 is ringed by a black or dark brown zone (mature larva)” is exhibited by all members of Antheraeopsis—it may actually function as an eyespot playing a role in defensive warning. This feature is not present in any other known Antheraea Figure 7. Intrasubgeneric phylogeny of the subgenus Antheraeopsis and current distribution. The stripes on the map (at the leftmost) indicate “uncertain ranges.” The phylogenetic tree on the left is the CMG result (Suppl. material 1: tree S1), and the one on the right is based on CMG + COI (Suppl. material 1: tree S2); the tree scale is only for the CMG result. The colors of the map correspond to the colors of the taxa on the phylogenetic trees.