Biodiversity Data Journal :
Single Taxon Treatment
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Corresponding author: Ayman Khamis Elsayed (ayman.khamis77@gmail.com)
Academic editor: Vladimir Blagoderov
Received: 23 Apr 2019 | Accepted: 08 Jul 2019 | Published: 29 Jul 2019
© 2019 Ayman Elsayed, 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:
Elsayed AK, Yukawa J, Tokuda M (2019) Pseudasphondylia tominagai, a new gall midge species (Diptera: Cecidomyiidae) inducing flower bud galls on Eleutherococcus spinosus (Araliaceae) in Japan. Biodiversity Data Journal 7: e35673. https://doi.org/10.3897/BDJ.7.e35673
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The genus Pseudasphondylia (Diptera: Cecidomyiidae: Asphondyliini: Asphondyliina) comprises ten Palearctic, Oriental and Australian species associated with various hosts belonging to at least ten plant families.
A new species, Pseudasphondylia tominagai Elsayed & Tokuda n. sp., that induces flower bud galls on Eleutherococcus spinosus (L.f.) S.Y.Hu (Araliaceae) is described. This species is considered to alternate between host plants seasonally. A key to males of known Pseudasphondylia species is provided.
Asphondyliini, Asphondyliina, host-alternation, taxonomic key
The genus Pseudasphondylia (Diptera: Cecidomyiidae: Asphondyliini: Asphondyliina), until now, comprised ten described species, eight of them in the eastern Palearctic, one in the Oriental and one in the Australian Region (
Amongst the ten previously described species, the life history has been surveyed for only five Japanese species. Pseudasphondylia neolitseae on Neolitsea sericea (Blume) Koidz. (Lauraceae), P. elaeocarpi on Elaeocarpus sylvestris var. ellipticus Hara (Elaeocarpaceae) and P. rokuharensis on Viburnum dilalatum Thunb. (Caprifoliaceae) are monophagous and univoltine (
The aim of the present study is to describe the new species of Pseudasphondylia found on E. spinosus. In addition, an identification key to males of Pseudasphondylia is provided and the possible life history pattern of the species is dicsussed.
Flower bud galls on E. spinosus (Fig.
Gall midge specimens were mounted on microscope slides in Canada balsam, following the technique outlined in
Morphological terminology mainly follows
The new species was compared to specimens of five Japanese congeners in KUEC.
Generic synopsis of Pseudasphondylia Monzen, 1955: see
Adult. Head (Fig.
Thorax: Anepisternum with 20–25 scales; anepimeron with 21–31 setae (n = 6); katepisternum bare. Lengths of leg parts as in Table
Sex |
Male (n=3) |
Female (n=4) |
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Mean |
Range |
Mean |
Range |
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Fore-leg |
Fumer |
770 |
760-780 |
719 |
685-740 |
Tibia |
787 |
780-790 |
748 |
730-770 |
|
Tarsomere I |
117 |
110-120 |
122 |
120-125 |
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Tarsomere II |
627 |
590-670 |
458 |
440-470 |
|
Tarsomere III |
307 |
300-310 |
194 |
180-210 |
|
Tarsomere IV |
203 |
190-210 |
125 |
115-140 |
|
Tarsomere V |
117 |
150-200 |
141 |
135-150 |
|
Mid-leg |
Fumer |
710 |
660-770 |
641 |
605-670 |
Tibia |
672 |
665-680 |
618 |
600-630 |
|
Tarsomere I |
107 |
105-110 |
120 |
120 |
|
Tarsomere II |
447 |
410-470 |
265 |
245-280 |
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Tarsomere III |
253 |
250-260 |
143 |
135-150 |
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Tarsomere IV |
160 |
150-170 |
96 |
90-100 |
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Tarsomere V |
145 |
140-150 |
131 |
120-140 |
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Hind-leg |
Fumer |
780 |
770-790 |
780 |
770-790 |
Tibia |
737 |
700-760 |
666 |
645-690 |
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Tarsomere I |
110 |
110 |
124 |
120-130 |
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Tarsomere II |
523 |
470-550 |
274 |
260-290 |
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Tarsomere III |
310 |
300-320 |
149 |
140-160 |
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Tarsomere IV |
197 |
190-210 |
106 |
100-110 |
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Tarsomere V |
167 |
140-200 |
136 |
130-140 |
Female abdomen (Fig.
Male abdomen: Tergites I–VII and sternites II–VI as for female; tergite VIII band-like, bare, with no discernible trichoid sensilla; sternites VII–VIII with anterior pair of trichoid sensilla, covered with scattered setae and scales, sternite VII width about as for VI, sternite VIII about 0.7 as wide as VII. Terminalia (Fig.
Third instar. Pale yellow, body strongly bowed backwards. Spatula (Fig.
Pupa (Fig.
Etymology: The species name, tominagai, honours Mr. A. Tominaga who collected the galls and reared the adults of this species.
Holotype: 1♂ (on slide): reared from flower bud gall on E. spinosus, collected in Misugi, Tsu City, Mie Prefecture, Japan, on 26.05.2018, emerged on 8.06.2018, A. Tominaga leg.
Paratypes: All paratypes (on slides) were reared from flower bud galls on E. spinosus in Japan by A. Tominaga. 4 larvae: galls collected in Misugi, Tsu City, Mie Prefecture on 26.05.2018, dissected on 26.05.2018; 4 larvae: galls collected in Higashi-Osaka City, Osaka Prefecture on 30.04.2018, dissected on 30.04.2018. 7 pupal exuviae, 5♀, 3♂: same data as holotype.
Distribution: Japan, Honshu: Osaka and Mie Prefectures.
Gall and life history: Pseudasphondylia tominagai induces flower bud galls on E. spinosus. The galled flower bud remains closed and reaches a diameter of 2.06–2.38 mm and length of 3.58–4.27 mm (n = 5) when matured. Larvae grow and pupate in the apical third of the galled bud. Third instars were found in the dissected galls in mid-April and adults emerged in late May.
Amongst the five known Pseudasphondylia species in Japan, P. tominagai can be separated easily from P. neolitseae, P. matatabi and P. elaeocarpi at least by the following characters: narrower wings (Fig.
Key to males of known Pseudasphondylia species |
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1 | Palpus with fewer than four segments | 2 |
– | Palpus with four segments | 6 |
2 | Palpus with three segments | 3 |
– | Palpus with two segments | P. neolitseae Yukawa |
3 | Empodia as long as tarsal claws | 4 |
– | Empodia distinctly longer than tarsal claws ( |
P. campanulata (Mani) |
4 | Gonostylus with dorsal setae | 5 |
– | Gonostylus without dorsal setae ( |
P. zanthoxyli Mo, Bu & Li |
5 | Tergites I–VII with two rows of posterior setae | P. matatabi (Yuasa & Kumazawa) |
– | Tergites I–VII with a single row of posterior setae | P. elaeocarpi Tokuda & Yukawa |
6 | Empodia as long as or slightly shorter than tarsal claws | 7 |
– | Empodia distinctly longer than tarsal claws ( |
P. diospyri Mo & Xu |
7 | Cerci shallowly separated | 8 |
– | Cerci deeply separated | 9 |
8 | Flagellomeres gradually becoming shorter from base to apex; hypoproct deeply notched ( |
P. rauwolfiae Coutin |
– | Flagellomeres equal in length; hypoproct shallowly notched ( |
P. philadelphi (Kovalev) |
9 | Each cercus wider than hypoproct, with rounded tips | 10 |
– | Each cercus narrower than hypoproct, with pointed tips | P. rokuharensis Monzen |
10 | Hypoproct deeply notched, slightly wider than each cercus | P. kiritanii Tokuda & Yukawa |
– | Hypoproct shallowly notched, narrower than each cercus | P. tominagai n. sp. |
In Pseudasphondylia tominagai, females of the overwintering generation lay eggs into flower buds of E. spinosus, which appear in March. Adult midges emerge from these flowers in late May when uninfested flower buds have already bloomed. Since we could not find any sign of larval presence in overwintering buds, we consider that P. tominagai possibly uses an alternative host plant from May to the following March.
In Diptera, the host-alternating habit has been known for only a few species of Asphondylia, such as A. gennadii (Marchal), A. yushimai Yukawa and Uechi, A. baca Monzen and A. sphaera Monzen (
We thank R. J. Gagné (Systematic Entomology Laboratory, USDA, Washington, DC, USA) for his valuable comments on the manuscript. We are grateful to Mr. A. Tominaga for collecting and rearing gall midge specimens of the new species. AKE is supported by JSPS International Research Fellowship no. P19087 (Graduate School of Science, The University of Tokyo, Japan).