Research Article |
Corresponding author: Hong-Xing Li ( lhx5340@163.com ) Academic editor: Mike Wilson
© 2019 Hong-Xing Li, Lin Yang Yang, Xiang-Sheng Chen.
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:
Li H-X, Yang L, Chen X-S (2019) Taxonomic study of the genus Malaxa Melichar, with descriptions of two new species from China (Hemiptera, Fulgoroidea, Delphacidae). ZooKeys 861: 43-52. https://doi.org/10.3897/zookeys.861.32777
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Two new species of the delphacid genus Malaxa Melichar, 1914, M. hamuliferum sp. nov. and M. tricuspis sp. nov., are described and illustrated from southwest China (Yunnan and Hainan), providing the genus with eleven species in total. A key is provided to distinguish the seven Chinese species in the genus.
Bamboo planthopper, Fulgoromorpha, morphology, oriental region, taxonomy
The genus Malaxa Melichar, 1914 (Hemiptera, Auchenorrhyncha, Fulgoroidea, Delphacidae) falls within the tribe Tropidocephalini in the subfamily Delphacinae and is easily recognized from other members in this tribe by the very long antennae, and by the tegmina often with blackish brown markings (
Species of Malaxa from China with reported plant associations feed on bamboo. Specimens have been collected on leaves of bamboo in several genera, including Bambusa, Indocalamus, Fargesia and Phyllostachys (
Herein, two new species: Malaxa hamuliferum sp. nov. and M. tricuspis sp. nov. are described and illustrated from Hainan and Yunnan province, China. A key to species of Malaxa from China is provided.
The morphological terminology and measurements follow
The type specimens of the new species are deposited in the Institute of Entomology, Guizhou University, Guiyang, China (IEGU).
Malaxa
Melichar, 1914: 275;
Malaxa acutipennis Melichar, 1914.
Description from
1 | Postclypeus yellow; tegmina with apical veins Cu1 and M3 diverging apically, posterior half of apical tegmina dark brown (see |
M. semifusca |
– | Postclypeus with basal half blackish brown; tegmina with apical veins Cu1 and M3 fused, first and second apical cells hyaline | 2 |
2 | Anal segment of male without process; aedeagus with phallobase | 3 |
– | Anal segment of male with a long process; aedeagus without phallobase | 4 |
3 | Genae with basal half dark brown, apical half yellowish white; tegmina mostly hyaline; pygofer with 3 medioventral processes very distinct; genital styles with inner margin without process (see |
M. bispinata |
– | Genae all dark brown; tegmina with basal half most yellow, apical half most dark brown; pygofer with medioventral processes not distinct; genital styles with inner margin with large process medially, hook-like (Figs |
M . hamuliferum sp. nov. |
4 | Genae dark brown; in posterior view, process of anal segment of male situated in middle of ventral margin ( |
M. hunanensis |
– | Genae mostly dark brown but apical with small part yellow; in posterior view, process of anal segment of male situated on left side of ventral margin | 5 |
5 | Genital styles with apex not forked; aedeagus with three processes (Figs |
M. tricuspis sp. nov. |
– | Genital styles with apex forked; aedeagus with two processes | 6 |
6 | Area between lateral carinae of pronotum dark brown; two branches of outer apical angle of genital styles subequal; aedeagus with a small spine situated near basal third, directed caudally (see |
M. delicata |
– | Area between lateral carinae of pronotum mostly yellow; two branches of outer apical angle of genital styles unequal; aedeagus with a small tooth situated near middle, directed right (see |
M. fusca |
Holotype: ♂, China: Yunnan, Yingjiang County (24°44'N, 97°33'E), on bamboo, 17 August 2018, Hong-Xing Li; paratypes, 5♂♂, 10♀♀, same data as holotype, Hong-Xing Li and Qiang Luo.
The specific name is derived from the Latin word “hamulus” and the postfix “-ferus”, referring to the middle of genital styles with large process, hook-like.
Body length including tegmina: male 3.9–4.1 mm (N = 10); female 4.8–5.0 mm (N = 5); tegmen length: male 3.4–3.6 mm (N = 10); female 4.0–4.4 mm (N = 5).
The salient features of the new species include the following: aedeagus with phallobase broad basally, apical third narrowing abruptly, and genital styles with large process at middle, hook-like.
Coloration. General color pale yellowish brown, with dark brown to black markings, shiny (Figs
Malaxa hamuliferum sp. nov. 5 head and thorax, dorsal view 6 same 7 face 8 tegmen 9 male genitalia, posterior view 10 same, lateral view 11 pygofer, ventral view 12 anal segment and aedeagus, lateral view 13 genital style, posterior view 14 same, left lateral view. Scale bars: 0.5 mm (5–8); 0.2 mm (9–14).
Head and thorax. Vertex (Figs
Male genitalia. Anal segment of male small, ring-like (Fig.
Bamboo.
Southwest China (Yunnan).
This species is similar to Malaxa semifusca Yang & Yang, 1986 but differs from it by: (1) frons and genae black, clypeus with basal half black (frons with apical third, genae with ventral half and clypeus yellow in M. semifusca); (2) anal segment of male without process (anal segment with left lateroapical process small and obtuse in M. semifusca); (3) aedeagus with phallobase without tooth at apex (aedeagus with phallobase incomplete, apex membraneous, with several teeth along margin and around apex in M. semifusca).
Holotype: ♂, China: Hainan, Wanning County (18°55'N, 110°20'E), on bamboo, 6 May 2017, Hong-Xing Li; paratypes, 6♂♂, 8♀♀, same data as holotype.
The specific name is derived from the Latin word “tricuspis”, referring to aedeagus with three small processes.
Body length including tegmina: male 3.5–3.7 mm (N = 7); female 4.1–4.3 mm (N = 8); tegmen length: male 3.0–3.2 mm (N = 7); female 3.5–3.8 mm (N = 8).
The salient features of the new species include the following: left lateroapical process of anal segment stout and twisted, tapering apically; aedeagus with three small processes.
Coloration. General color pale yellowish brown, with dark brown to black markings, shiny (Figs
Malaxa tricuspis sp. nov. 15 head and thorax, dorsal view 16 same 17 face 18 tegmen 19 male genitalia, posterior view 20 same, lateral view 21 pygofer, ventral view 22 anal segment and aedeagus, lateral view 23 aedeagus 24 genital style, left lateral view. Scale bars: 0.5 mm (15–18); 0.2 mm (19–22); 0.1 mm (23, 24).
Head and thorax. Vertex (Figs
Male genitalia. Anal segment of male small, ring like, left lateroapical process stout and twisted, tapering to apex (Fig.
Bamboo.
Southwest China (Hainan).
This species is similar to Malaxa fusca Yang & Yang, 1986 but differs from it by: (1) anal segment of male with left lateroapical process twisted but not S-like, not swelled subapically (anal segment with left lateroapical process twisted, S-like, swelled subapically in M. fusca); (2) aedeagus with stout process at base, a spine at basal third and with small tooth at apical third (aedeagus with small process at base and with a spine near middle in M. fusca); (3) genital styles with apical half narrowing abruptly, not forked at apex (genital styles with outer angle forked at apex, inner branch longer than outer one in M. fusca).
This species is also similar to M. delicata Ding & Yang, 1986 but differs from it by: (1) anal segment of male with left lateroapical process twisted near base (anal segment with left lateroapical process twisted near apex in M. delicata) (2) aedeagus with stout process at base, a spine at basal third and with small tooth at apical third (aedeagus with process at base and with small spine at basal third in M. delicata); (3) genital styles with outer angle not forked at apex (genital styles with outer angle forked at apex, two branches subequally long in M. delicata).
The Malaxa species distributed in China with common type characters: body slender and elongate, often with blackish brown markings; antennae cylindrical, very long, surpassing apex of clypeus, basal segment shorter than the second segment (0.40–0.56: 1); tegmina apically rounded, leading margin straight; anal tube of male either simple or with 1–2 processes; opening of pygofer usually bearing two broad lamellate medioventral processes, between them a V-like emargination; genital styles broad in basal half, forked or with process at apex; aedeagus with or without phallobase, phallus tubular, curved C-like and directed segmental venter. Based mainly on the characters of the morphological and male genitalia, we also found obvious differences between the Chinese Malaxa and the type species M. acutipennis, which agrees
The authors are grateful to collectors for the specimens. This work is supported by the National Natural Science Foundation of China (No. 31472033, 31160163), the Program of Science and Technology Innovation Talents Team, Guizhou Province (No. 20144001), the Program of Excellent Innovation Talents, Guizhou Province (No. 20154021), and the Youth Science and Technology Talent Development Project in the Education Department of Guizhou Province (Grant No. qianjiaohe KY zi [2017]103).