Biodiversity Data Journal :
Taxonomic Paper
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Corresponding author: Makoto Tokuda (tokudam@cc.saga-u.ac.jp)
Academic editor: AJ Fleming
Received: 28 Apr 2021 | Accepted: 28 May 2021 | Published: 17 Jun 2021
© 2021 Hiroki Matsuda, Ayman Elsayed, Wanggyu Kim, Satoshi Yamauchi, Martin Libra, Naoto Kamata, Junichi Yukawa, Makoto Tokuda
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:
Matsuda H, Elsayed AK, Kim W, Yamauchi S, Libra M, Kamata N, Yukawa J, Tokuda M (2021) A new species of Pseudasphondylia (Diptera: Cecidomyiidae) associated with Magnolia kobus DC. var. borealis Sarg. (Magnoliaceae) in Japan. Biodiversity Data Journal 9: e68016. https://doi.org/10.3897/BDJ.9.e68016
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A gall midge species (Diptera: Cecidomyiidae) inducing leaf bud galls on Magnolia kobus var. borealis Sarg. (Magnoliaceae) was found in Hokkaido and northern Honshu, Japan.
Based on its morphology, the species is regarded as an undescribed species of the genus Pseudasphondylia Monzen (Cecidomyiinae, Cecidomyiidi, Asphondyliini). The species is herein described as Pseudasphondylia saohimea Matsuda, Elsayed and Tokuda sp. n. The new species is easily distinguishable from its congeners by the number of adult palpal segments and the shape of the male terminalia and larval spatula.
Asphondyliini, Asphondyliina, gall midge, molecular phylogeny
The genus Pseudasphondylia (Diptera: Cecidomyiidae: Asphondyliini) includes 11 species associated with various plant families (
In recent years, we found an undescribed species of asphondyliine gall midge that induces leaf bud galls on Magnolia kobus var. borealis Sarg. (Magnoliaceae) in Tomakomai, Hokkaido and Aomori Prefecture, Honshu, Japan. Based on morphological comparison, we concluded that the gall midge is a member of Pseudasphondylia. We describe the species as new to science and discuss the phylogenetic relationships amongst Japanese congeners on the basis of molecular analysis. We also compare its life history strategy with those of the Japanese congeners.
Leaf-bud galls on M. kobus var. borealis (Fig.
Gall midge specimens were mounted on slides in Canada balsam, following the technique outlined in
Morphological terminology basically follows
Genome DNA was extracted from 99.5% ethanol-preserved female gall midges reared from leaf galls of M. kobus var. borealis and of P. tominagai reared from flower bud galls of E. spinosus (
Besides the obtained sequence data, sequences of four species of Pseudasphondylia and four species of Asphondylia were downloaded from the GenBank and used as ingroup taxa: P. rokuharensis (LC538357), P. kiritanii (LC538356), P. matatabi (AB085873) (
Head (Fig.
Thorax (Fig.
Female abdomen (Fig.
Male abdomen (Fig.
Mature larva (Fig.
Pupa (Fig.
The specific name, saohimea, is derived from “Saohime”, a Japanese goddess of spring, because blooming of the host plant Magnolia kobus var. borealis is a symbolic event announcing the beginning of spring in northern Japan. Galls of P. saohimea become conspicuous on the host also in early spring.
Japan, Hokkaido and Honshu (Aomori Prefecture).
Pseudasphondylia saohimea is univoltine. Third instars and pupae were found in the galls in mid-May and adults emerged directly from the galls in mid- to late May. All mature galls collected in July were empty, indicating that no individuals had entered long-term diapause. In rearing conditions, adults emerged in the morning and mated around 11:00 h, suggesting that the gall midge is a diurnal species. The adults are supposed to oviposit into host buds. First instars were found in undeveloped bud galls in late September. They possibly overwinter in the undeveloped bud galls and develop to the second and third instars in the following spring.
Magnolia kobus var. borealis Sarg. (Magnoliaceae), “Kita-kobushi” in Japanese.
Pseudasphondylia saohimea induces hairy leaf bud galls on Magnolia kobus var. borealis (Magnoliaceae). The galled buds remain closed and indistinguishable in appearance from ungalled buds until the following spring and rapidly grow with bud burst. Mature galls are 2.7–6.0 mm in diameter and 5.1–13.7 mm in length (n = 45). Galls are multi-chambered and each chamber contains a single gall midge larva.
The following three species of hymenopteran parasitoids were reared from the mature galls: Pseudocatolaccus sp. (Pteromalidae) from Hokkaido and Aomori, Torymus sp. (Torymidae) from Hokkaido and Eurytoma sp. (Eurytomidae) from Aomori.
The new species is distinguishable from most of its other congeners in Japan by the number of palpal segments: three in the new species, but two in P. neolitseae and four in P. rokuharensis, P. kiritanii and P. tominagai. Although P. matatabi and P. elaeocarpi have three-segmented palpi, they are easily distinguished from the new species by their cerci which are shorter than the hypoproct. The larval spatula of the new species has four lobes of which the outer two are longer than the inner two. However, the larval spatula of P. neolitseae has only two lobes anteriorly and the other species have four lobes of which the inner two are longer than the outer two. In the pupa, five pairs of long abdominal spiracles are present in the new species, while only three pairs are present in P. rokuharensis, P. kiritanii, P. elaeocarpi and P. tominagai and four pairs in P. matatabi. The pupa of P. neolitseae, which has five pairs of abdominal spiracles, is otherwise similar to the new species, but it can be distinguished by dorsal abdominal spines that are markedly shorter than in P. saohimea.
In the key to the males of world Pseudasphondylia species in
Placement of Pseudasphondylia saohimea in the key to males of worldwide Pseudasphondylia (
5 | Tergites I–VII with 2–3 posterior rows of setae | 5’ |
Tergites I–VII with 1 posterior row of setae | P. elaeocarpi Tokuda & Yukawa | |
5' | Cerci shallowly separated ( |
P. matatabi (Yukawa & Kumazawa) |
Cerci deeply separated, each cercus oval (Fig. |
P. saohimea sp. n. |
In the ML tree (Fig.
Morphological examination and phylogenetic analysis clearly indicate that P. saohimea is distinct from its congeners in Japan, although phylogenetic relationships amongst Pseudasphondylia species were not revealed in the analyses, except for the sister group relationship of P. kiritanii and P. tominagai. Pseudasphondylia was hypothesised to be an ancient clade within the subtribe Asphondyliina (
Based on overwintering sites and larval stages, the life-history of gall midges is divided into two main types, of which each can be subdivided into two subtypes regardless of uni-, bi- or multivoltine (
As mentioned above, P. saohimea belongs to the univoltine type IIB, as does P. elaeocarpi (
Some Asphondyliini, other than Pseudasphondylia, have a life history pattern similar to that of P. saohimea. For example, females of Oxycephalomyia styraci (Shinji) oviposit into axillary overwintering buds of Styrax japonica Siebold and Zucc. (Styracaceae) and its larvae spend summer, autumn and winter as the first instar in the host buds; then, galls and larvae rapidly grow, coinciding with host bud burst (
Some large genera, such as Asphondylia, Contarinia, Dasineura and Lasioptera, are associated with various plant families, while others are restricted to particular plant genera, namely Caryomyia on Carya (Juglandaceae), Procontarinia on Mangifera (Anacardiaceae), Rabdophaga on Salix (Salicaceae) and Semudobia on Betula (Betulaceae) (
We thank R. J. Gagné for his critical reading of an early draft, T. Ichita, T. Minami and S. Sato for their help in searching galls and K. Matsuo for identification of parasitoids. This study was partly supported by JSPS Standard International Postdoctoral Research Fellowship (no. P19087; to Ayman K. Elsayed), European Research Council (GA669609; to Martin Libra) and JSPS Grant-in-Aid for Challenging Exploratory Research (Grant no. 26550087; to Naoto Kamata). Some materials used in this study were obtained through field surveys performed by the Board of Education of Mutsu City, Aomori Prefecture, to which our hearty thanks are extended.