Review Article |
Corresponding author: Dandan Zhang ( zhdd61@163.com ) Academic editor: Bernard Landry
© 2019 Kai Chen, Qingming Liu, Jianhua Jin, Dandan Zhang.
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.
Citation:
Chen K, Liu Q, Jin J, Zhang D (2019) Revision of the genus Emphylica Turner, 1913 based on morphology and molecular data (Lepidoptera, Crambidae, Pyraustinae). ZooKeys 836: 113-133. https://doi.org/10.3897/zookeys.836.32796
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Moths of the genus Emphylica Turner, 1913 resemble species of Achyra Guenée, 1849, Loxostege Hübner, 1825 and Sitochroa Hübner, 1825 in having a conical frons. In order to examine the monophyly of Emphylica, and its relationship to other genera with a conical frons, a molecular phylogenetic framework is reconstructed based on sequence data of COI, 16S rRNA, 28S rRNA, EF-1α and Wg gene regions. The results robustly support the monophyly of Emphylica. Achyra + (Loxostege + Sitochroa) is in a sister position to Emphylica. A new species, E. crassihamata sp. n., is described from Southern China and two new combinations, E. diaphana (Caradja & Meyrick, 1934), comb. n. and E. cruoralis (Warren, 1895), comb. n., are proposed. An identification key based on males is provided for all Emphylica species. The adult habitus and genitalia of all species are figured.
Achyra, China, conical frons, Loxostege, molecular phylogeny, new combinations, new species, Sitochroa
Emphylica was established by
The frons of pyraustine species is usually flat or round, seldom projecting conically. Based on current knowledge, only the Australian genus Emphylica Turner, the genus Achyra Guenée with a worldwide distribution, the mainly Holarctic genera Loxostege Hübner and Sitochroa Hübner, as well as the New World genera Hahncappsia Munroe, Neohelvibotys Munroe and Helvibotys Munroe have a conical frons. These genera (except Emphylica) were considered closely related to each other based on external characters (
While examining pyraustine collections from southern China and Southeast Asia, Loxostege diaphana Caradja & Meyrick, 1934, Pyrausta cruoralis (Warren, 1895) and an undescribed species, all resembling Emphylica xanthocrossa in the conical frons and the relatively small wingspan (less than 20 mm), attracted our attention. Further studies based on the genitalic characters suggested that the two described species definitely did not belong to their current genera and these three species were closely related to Emphylica. In order to evaluate the generic placement of these species, the phylogenetic relationships of Emphylica and potentially related genera, Achyra, Loxostege, and Sitochroa, were studied based on genetic data. The taxonomic composition and morphology of Emphylica are redefined.
In total eleven species of five genera were included for molecular phylogenetic analysis (Table
Taxon | Voucher | Locality | GenBank accession number | References | ||||
COI | 16S | 28S | EF1-α | Wg | ||||
Pseudebulea fentoni | SYSULEP0074 | Hunan | MG739570 | MG739582 | MG739605 | MG739594 | MK506279 | Chen et al. 2018; present study |
Emphylica crassihamata | SYSULEP0190 | Guangdong | MK506732 | MK506755 | MK506767 | MK506744 | MK506728 | present study |
Emphylica crassihamata | SYSULEP0191 | Hunan | MK506733 | MK506756 | MK506768 | MK506745 | MK506727 | present study |
Loxostege deliblatica | SYSULEP0200 | Xinjiang | MK506734 | MK506757 | MK506769 | MK506746 | MK506726 | present study |
Loxostege sticticalis | SYSULEP0227 | Xinjiang | MK506735 | MK506758 | MK506770 | MK506747 | MK506725 | present study |
Achyra massalis | SYSULEP0242 | Shanxi | MK506736 | MK506759 | MK506771 | N/A | MK506724 | present study |
Sitochroa verticalis | SYSULEP0257 | Xinjiang | MK506737 | MK506760 | MK506772 | MK506748 | MK506723 | present study |
Sitochroa palealis | SYSULEP0258 | Xinjiang | MK506738 | MK506761 | MK506773 | MK506749 | MK506722 | present study |
Emphylica diaphana | SYSULEP0263 | Fujian | MK506739 | MK506762 | MK506774 | MK506750 | MK506719 | present study |
Emphylica diaphana | SYSULEP0264 | Guangdong | MK506740 | MK506763 | MK506775 | MK506751 | MK506720 | present study |
Emphylica xanthocrossa | SYSULEP0307 | Western Australia | MK506741 | MK506764 | MK506776 | MK506752 | MK506730 | present study |
Emphylica cruoralis | SYSULEP0377 | Tibet | MK506742 | MK506765 | MK506777 | MK506753 | MK506721 | present study |
Sitochroa umbrosalis | SYSULEPT014 | Fujian | MK506743 | MK506766 | MK506778 | MK506754 | MK506731 | present study |
Total DNA was extracted from two legs and sometimes in addition from the abdomen of the dry specimens using the TIANGEN DNA extraction kit following the manufacturer’s instructions. The nucleotide sequences of two mitochondrial genes, cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (16S rRNA), and three nuclear genes, 28S ribosomal RNA (28S rRNA), Elongation factor-1 alpha (EF-1α) and Wingless (Wg) were selected for study. Primers used in this study are as follow: LCO/Nancy for COI and LepWg1/LepWg2 for Wg (
The sequences were aligned using Clustal W (
Morphological analysis. The specimens studied, including the types of the newly described species, are deposited in the Museum of Biology, Sun Yat-sen University, Guangzhou (SYSBM), except for those held at the following institutions: the Insect Collection of the College of Life Sciences, Nankai University (
The concatenated dataset of five genes consisted of 2873 nucleotide positions (658 for COI, 466 for 16S, 612 for 28S rRNA, 753 for EF-1α and 384 for Wg). Both BI and ML analyses of the concatenated dataset inferred congruent topologies with only subtle differences in posterior probability and bootstrap values probability (Fig.
The results of the current phylogenetic analyses support that the undescribed species (here named as E. crassihamata sp. n.) should be placed in Emphylica, and that E. diaphana comb. n. should be transferred from Loxostege to Emphylica and E. cruoralis comb. n. should be transferred from Pyrausta to Emphylica. Emphylica xanthocrossa and E. crassihamata + E. cruoralis form a sister group, although with low support in the ML analysis (BS = 40).
Pairwise distances of the barcoding region (COI) are given in Table
Pairwise distances of the COI barcode region based on Kimura-2-parameter model (intraspecific distances are highlighted in bold).
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | ||
1 | LEP0190 Emphylica crassihamata | ||||||||||||
2 | LEP0191 Emphylica crassihamata | 0.000 | |||||||||||
3 | LEP0263 Emphylica diaphana | 0.083 | 0.083 | ||||||||||
4 | LEP0264 Emphylica diaphana | 0.079 | 0.079 | 0.008 | |||||||||
5 | LEP0307 Emphylica xanthocrossa | 0.066 | 0.066 | 0.081 | 0.075 | ||||||||
6 | LEP0377 Emphylica cruoralis | 0.040 | 0.040 | 0.077 | 0.074 | 0.063 | |||||||
7 | LEP0200 Loxostege deliblatica | 0.108 | 0.108 | 0.112 | 0.112 | 0.086 | 0.096 | ||||||
8 | LEP0227 Loxostege sticticalis | 0.102 | 0.102 | 0.087 | 0.085 | 0.083 | 0.090 | 0.076 | |||||
9 | LEP0242 Achyra massalis | 0.100 | 0.100 | 0.092 | 0.096 | 0.098 | 0.089 | 0.090 | 0.083 | ||||
10 | LEP0257 Sitochroa verticalis | 0.123 | 0.123 | 0.112 | 0.108 | 0.104 | 0.116 | 0.090 | 0.087 | 0.116 | |||
11 | LEP0258 Sitochroa palealis | 0.092 | 0.092 | 0.106 | 0.102 | 0.085 | 0.094 | 0.073 | 0.086 | 0.090 | 0.058 | ||
12 | LEPT014 Sitochroa umbrosalis | 0.123 | 0.123 | 0.129 | 0.122 | 0.118 | 0.120 | 0.089 | 0.102 | 0.112 | 0.060 | 0.056 | |
13 | LEP0074 Pseudebulea fentoni | 0.133 | 0.133 | 0.144 | 0.141 | 0.135 | 0.146 | 0.147 | 0.144 | 0.148 | 0.155 | 0.137 | 0.159 |
Emphylica Turner, 1913: 159. Type species: Emphylica xanthocrossa Turner, 1913, by monotypy.
Species of Emphylica have a conical frons (Figs
Head. Frons conical. Vertex with moderately raised scales projecting between antennae. Labial palpus slightly upwardly curved, approximately twice as long as diameter of eye; first segment with white scales at base; second segment obliquely directed upward; third segment long, porrect. Maxillary palpus prominent, curved upward. Proboscis well developed, with creamy white scales at base. Antenna in male with cilia shorter than or as long as width of corresponding flagellomeres. Thorax. Dorsal side whitish brown to brown; ventral side whitish to pale yellow. Legs unmodified, hindleg with basal inner spur longer than apical inner spur, approximately three times as long as basal outer spur. Wings. Forewing elongate-triangular, costa straight to near apex, then slightly arched to apex; apex sharp; termen weakly arched, oblique to tornus; dorsum straight; upperside usually with reddish or pale brown scales; frenulum hook in male well developed, retinaculum made up a tuft of curved bristles from below base of discal cell. Hindwing broad, fan-shaped; terminal margin usually brown; frenulum simple in male, with 2 acanthae in female. Wing venation as in Fig.
All of the Chinese material has been collected during the night at light. Host information is currently unavailable.
(Fig.
1 | Wingspan usually less than 15 mm (Fig. |
E. xanthocrossa Turner, 1913 |
– | Wingspan usually larger than 17 mm. Uncus not concave distally, ductus ejaculatorius originating from the anterior end of the phallus | 2 |
2 | Ground colour of the wings whitish (Fig. |
E. diaphana (Caradja & Meyrick, 1934), comb. n. |
– | Ground colour of the wings reddish brown or yellow. Uncus trapezoid, ventral sella not reaching ventral margin of valva (Figs |
3 |
3 | Basal 2/3 of forewing predominantly reddish brown (Fig. |
E. cruoralis (Warren, 1895), comb. n. |
– | Basal 2/3 of forewing yellow, sprinkled with reddish brown scales (Fig. |
E. crassihamata sp. n. |
Loxostege diaphana Caradja & Meyrick, 1934: 164.
CHINA, Fujian: 1♂, Letu rain forest, Hexi, Nanjing, 24.90N, 117.22E, alt. 270 m, 10.VII.2014, leg. Zhang Dandan, genitalia slide no. SYSU1040, molecular voucher no. SYSU-LEP0263; Guangdong: 1♂, Sanyue Reserve, 24.03N, 111.57E, alt. 272 m, 6.VII.2013, leg. Chen Xiaohua, genitalia slide no. SYSU1041, molecular voucher no. SYSU-LEP0264; Hainan: 1♂, Mt. Limushan, 5.V.2011, leg. Zhang Dandan and Yang Lijun; Chongqing: 1♀, Daheba, Mt. Jinfoshan, alt. 800–850 m, 15.VII.2010, leg. Du Xicui and Song Lifang, genitalia slides no. SYSU0969; 1♂, Daheba, Mt. Jinfoshan, alt. 800–850 m, 16.VII.2010, leg. Du Xicui and Song Lifang, genitalia slides no. SYSU0965.
Emphylica diaphana resembles other Emphylica species in the conical frons and the scale-like setae of the sella. It can be best distinguished from its congeners by the whitish ground colour suffused with pale brown scales on both wings, the dark brown lines at termen, in male genitalia by the triangular, distally narrowly-rounded uncus bearing only few short setae and the long, strongly sclerotized ventral sella usually projecting beyond the ventral margin of the valva. In female genitalia of E. diaphana, the antrum is strongly sclerotized, shorter than the length of the anterior apophysis, slightly wider than the ductus bursae; the maximal length of the signum is approximately 2/3 as long as the diameter of the corpus bursae; the two opposing angles of the signum without carinae are well-developed, almost as long as the other two. In E. xanthocrossa the antrum is broad, lightly sclerotized, no more than twice as wide as the ductus bursae; the two opposing angles of the signum without carinae are fairly short; in E. crassihamata the antrum is longer than the anterior apophysis, in E. cruoralis the antrum is as long as the anterior apophysis and the signum of both species is small (less than half of the diameter of the corpus bursae).
(Figs
(Fig.
This species was formerly placed in the genus Loxostege, probably based on the conical frons. However, genitalia traits of Loxostege moths, e.g. the cylindrical uncus with dense, scale-like setae, the few hair-like setae of the dorsal sella, the ventrobasally directed ventral sella and the usually coiled ductus bursae, are different in Emphylica diaphana. Although in appearance the wing colour and pattern of this species are somewhat dissimilar to those of other Emphylica species, the genitalia traits agree with the diagnostic characters of Emphylica xanthocrossa Turner, the type species. Moreover, according to the molecular phylogeny, this species was inferred as terminal lineage within Emphylica, rather than in Loxostege. Consequently, this species is considered as correctly placed in Emphylica.
Type material. Holotype ♂ (Fig.
In appearance, E. crassihamata resembles E. cruoralis in the reddish brown subterminal band, but can still be recognized by the predominantly yellow basal 2/3 of the forewing sprinkled with reddish brown scales and the presence of a faint antemedial line on the forewing and postmedial lines on both wings. In male genitalia it differs from E. diaphana and E. xanthocrossa by the distally rounded, moderately setose uncus, the pointed and recurved dorsal process of the sacculus, and the long and slender phallus, which is longer than the length of the valva; from E. cruoralis it differs by the wider distal uncus, the small triangular, strongly sclerotized process near the distal sacculus as well as the hook-like ventral sella. In female genitalia, the sclerotized antrum is approximately 1.5× as long as the anterior apophysis whereas in E. cruoralis the sclerotized antrum is as long as the anterior apophysis.
(Figs
(Fig.
The specific name is derived from the Latin crassi- = thick and hamata = hook-like, referring to the thick, hook-like ventral sella.
(Fig.
Syllythria cruoralis Warren, 1895: 471.
Pyrausta cruoralis
(Warren, 1895):
Type material. Lectotype (here designated) ♂: INDIA, Meghalaya: Khasis, Mar.1894, Nat. Coll., Pyralidae
INDIA, Meghalaya: 7♂ (Fig.
Emphylica cruoralis resembles E. crassihamata in the reddish brown subterminal band and the saffron fringe. The differences between the two species are provided in the diagnosis of E. crassihamata. In appearance, E. cruoralis can be best recognized within the genus by the yellow postmedial band of the forewing, in male genitalia by the narrow trapezoid uncus with hair-like setae at distal third, the large, thumb-shaped, weakly sclerotized process of the ventral valva near the distal sacculus as well as the triangular ventral sella overlaid by a folded, distally blunt process. In female genitalia, it resembles E. crassihamata except for the less sinuate distolateral antrum and the relatively shorter and wider antrum anteriorly.
(Figs
(Fig.
This species was formerly placed in the genus Pyrausta. However, both the molecular phylogeny and the genital traits suggested that it should be placed in Emphylica. According to the male genitalia (Fig.
Emphylica xanthocrossa Turner, 1913: 159.
Type material. Holotype, ♀: AUSTRALIA, Northern Territory: P[ort]. Darwin, Nov.[19]08, leg. F.P. Dodd, genitalia slide no. P232 (
(
Female genitalia of Emphylica spp., ventral views 20 E. diaphana, Chongqing (genitalia slide no. SYSU0969) 21 E. crassihamata, Hunan (genitalia slide no. SYSU0957) 22 E. cruoralis, Tibet (genitalia slide no. ZDD12100) 23 E. xanthocrossa, Queensland (genitalia slide no. ANIC18162). Scale bar: 1.0 mm.
Emphylica xanthocrossa resembles E. crassihamata and E. cruoralis in the saffron fringe, the conical frons and the U-shaped juxta. It can be best distinguished from its congeners by the smaller wingspan (less than 15 mm), the triangular saffron spot on the forewing costa postmedially, the smoky brown subterminal margin of the hindwing, in male genitalia by the distally concave uncus, the spinulose ventral sella, the absence of a dorsal process on the sacculus, the larger juxta, the broad and slightly sinuate phallus and the ductus ejaculatorius originating from the middle of the phallus. In female genitalia, the antrum is moderately sclerotized, bottle-shaped, the two opposing angles of the signum without carinae are short, whereas in E. diaphana, E. crassihamata and E. cruoralis the antrum is strongly sclerotized and the two opposing angles of the signum without carinae are almost as long as the other two.
(Figs
Based on the molecular phylogeny, the clade Achyra + (Loxostege + Sitochroa) is a sister group to Emphylica. All these four genera have a similar conical frons. Species of Achyra can be distinguished from Emphylica in male genitalia by the narrow triangular uncus laterally set with dense hair-like setae, the dense simple setae of the sella and in female genitalia by the presence of a second signum and the broad base of the ductus seminalis. Species of Loxostege differ from Emphylica in male genitalia by the cylindrical uncus set with scale-like setae, the few simple setae of the sella and in female genitalia by the long and coiled ductus bursae with a sclerotized base. Species of Sitochroa are best distinguished from Emphylica in male genitalia by the ventral sella with two hook-like, basally curved processes and the strongly sclerotized process extending from the phallus apically, and in female genitalia by the twisted sclerite near the posterior end of the ductus bursae. Hahncappsia, Neohelvibotys and Helvibotys, mainly distributed in the Nearctic and Neotropical regions, are not included in the current phylogenetic analysis. External characters of these three genera are similar to those of Achyra, Loxostege and Sitochroa (Munroe, 1976a). The morphological details were provided by
The monophyly of Emphylica is robustly supported by the results of the molecular analysis. Four species can be recognized as members of Emphylica based on the series of morphological characters provided above in the diagnosis of the genus. According to the tree topology (Fig.
Emphylica is recorded for the first time from outside Australia. The current study shows that Emphylica species occur in Southern China, the northwest of India and the north of Australia. There is as yet no record of Emphylica species in Indochina and the Malay Archipelago. Noteworthily, there are three Pyrausta spp., probably congeneric with Emphylica, recorded in Borneo (see http://www.pyralidsofborneo.org/index.php?cruoralis; http://www.pyralidsofborneo.org/index.php?sp4-17; http://www.pyralidsofborneo.org/index.php?sp5-10). The specimen identified as P. cruoralis is very similar to E. cruoralis in wing pattern, but with much narrower yellow bands on both wings. The wing pattern of another specimen identified as P. sp4 is almost the same as the former specimen, but the wingspan is similar to that of E. xanthocrossa. The last specimen identified as P. sp5 also has yellow bands of both wings similar to those of E. cruoralis. Unfortunately, the frons of these specimens cannot be observed, and no image of genitalia or genetic data can be accessed. Considering the similarity in the wing pattern, it would not be a surprise if these three taxa turn out to be congeneric with Emphylica species.
We would like to express our grateful thanks to Dr Andreas Zwick, Mr Youning Su (both CSIRO, NRCA, Australia) and Prof. Houhun Li (