Macarangamyia itiokai Elsayed & Tokuda, 2018

Elsayed, Ayman Khamis, Shimizu-Kaya, Usun, Itioka, Takao, Meleng, Paulus, Yukawa, Junichi & Tokuda, Makoto, 2018, A new genus and a new species of Schizomyiina (Diptera: Cecidomyiidae: Asphondyliini) inducing petiole galls on Macaranga bancana (Miq.) in Borneo, Malaysia, Zootaxa 4482 (1), pp. 188-196 : 193-194

Macarangamyia itiokai Elsayed & Tokuda sp. nov.

Head ( Fig. 2 ): Compound eye bridge 6–7 facets long. Fronto-clypeal setae 9–13 (n = 13). Mouthparts: palpi foursegmented, first ca. 40.3 µm (28–47 µm), second ca. 35.7 µm (31–42 µm), third ca. 50.9 µm (40–63 µm), fourth ca. 78.3 µm (60–90 µm) (n = 9); labrum with microtrichous edges; labium setose.

Thorax: Wing ( Fig. 5 ), length 1.79–1.96 mm in female (n = 4), 1.54–1.74 mm in male (n = 6); M3+4 and Cu very weak. Anepimeral setae 6–9 (n = 9); other pleural sclerites bare.

Female abdomen: Sternite VII about 3.3 times as long as preceding sternite. Ovipositor ( Fig. 8–9 ): the protrusible portion about as long as sternite VII.

Male abdomen: Terminalia ( Fig. 11 ): Gonocoxite about 2.2 times as long as width. Gonostylus with strong setae on the distal two thirds and unfused denticles covering most of the posterior margin. Cerci entirely microtrichous, setose. Hypoproct microtrichous. Parameres with several fine setae apically.

Full-grown larva: Sternal spatula broadened, length about 1.3 as long as width ( Fig. 13 ). All thoracic segments and abdominal segments with ventral field of spinules, except prothoracic segment and terminal abdominal segment.

Pupa ( Figs. 14–15 ): Antennal horns well-developed, each horn bidentate in the lateral view; two facial horns present, pointed; two lower facial papillae present between the facial horns, each with 24 to 43 µm (n = 6) long seta; two lateral facial papillae present on each side, each with very short seta; two pairs of cephalic papillae present, each pair consisting of one setose and one asetose papilla.. Prothoracic spiracle curved, about 135 to 165 µm (n = 7) in length, with trachea extending to the tip. Four dorsal papillae present on abdominal segment I–VII, only the outermost pair with setae. Abdominal segment VIII with only two setose papillae.

Etymology: This species is named in honor of Dr. Takao Itioka (Kyoto University, Japan) for his studies on the interactions between Macaranga spp., their symbiotic ants and other herbivorous insects in Borneo, Malaysia (e.g. Itioka et al. 2000; Itioka 2005; Shimizu-kaya & Itioka 2016).

Holotype: 1♂: Lambir Hills National Park , Borneo, Malaysia; collected on 26.vi.2013, Shimizu-kaya, U. leg., reared by Shimizu-kaya, U. from a petiole gall on M. bancana , deposited in FDSM.

Paratypes: All were collected and reared from petiole galls on M. bancana collected from Lambir Hills National Park, Borneo, Malaysia by Shimizu-kaya, U. Deposited in FDSM: 8♂, 3♀ & 6 pupal exuviae: collected on 26.vi.2013 ; 1♀ & 1 pupal exuviae: collected on 7.vii.2013. Deposited in KUEC: 10 pupal exuviae: collected on 26.vi.2013; 1 larva: collected on 7.vii.2013; 6♂, 4♀ & 3 pupal exuviae: collected on 1.iv.2014; 1♂: collected on 22.iv.2014.

Distribution: Lambir Hills National Park, Borneo, Malaysia.

Biology: Macarangamyia itiokai induces spheroid galls on petioles of M. bancana . Two or more swellings are frequently fused together (1.2–3.0 mm in length, 0.8–1.5 mm in diameter, n = 6) and contain 2–15 (n = 12) small larval chambers. Each larval chamber contains only one larva. The pupation takes place inside galls.

Remarks. The new genus, Macarangamyia is distinguishable among all other Asphondyliini genera by the presence of well-developed dorsal and ventral aedeagus slit that is usually tiny and unnoticeable in Asphondyliini , except in some Australian species, namely Schizomyia novoguineensis Kolesik (Kolesik & Butterill 2015) , Okriomyia flabellidentata Kolesik , O. schwarzi Kolesik (Kolesik 1998) and Eocincticornia malarskii Kolesik (Kolesik 1995) , and the presence of spiracles on the larval meso- and metathoracic segments, which are usually absent in Cecidomyiidi ( Gagné 1994), except for the larvae of Paracalmonia paucula Gagné that possesses spiracles only on metathorax (Gagné & Étienne 2009).

At present, only three genera of Schizomyiina are known from the Oriental region, i.e. Asphoxenomyia Felt , Luzonomyia Felt , and Schizomyia Kieffer ( Gagné & Jaschhof 2017) . Schizomyia is quite apart from Macarangamyia because female Schizomyia have needle-like ovipositors, while Asphoxenomyia and Luzonomyia are closer morphologically to Macarangamyia because of their short ovipositors. Macarangamyia can be distinguished from Asphoxenomyia as follows ( Felt 1927; Peter Kolesik, personal communication): Macarangamyia has four-segmented palpi, while Asphoxenomyia have one-segmented palpi; tarsal claws of Macarangamyia are simple, but toothed in Asphoxenomyia ; ovipositor of Macarangamyia with tiny cerci distally, but that of Asphoxenomyia with large cerci (about 1/4 as long as the protrusible portion). The ovipositor of Luzonomyia ( Fig. 16 ) is similar to the ovipositor of Macarangamyia, but the two genera can be separated from each other as follows: Macarangamyia has four-segmented palpi, while in Luzonomyia they are three-segmented; male flagellomeres of Macarangamyia have sinuous circumfila, but Luzonomyia has two connected rings of circumfila ( Fig. 17 ); anterior pair of trichoid sensilla is absent on the abdominal tergites of both sexes of Macarangamyia, but present only in the female of Luzonomyia ; Macarangamyia has a cylindrical aedeagus and broad gonostylus, but Luzonomyia with a broad aedeagus and pointed gonostylus ( Gagné 1969; Felt 1918).

The full-grown larva of Macarangamyia has a bidentate sternal spatula and elongated and tapered terminal abdominal segment. This feature is distinctly different from that of Schizomyia and rather similar to Bruggmannia Tavares , a Neotropical genus of Schizomyiina . However, Bruggmannia can be separated from Macarangamyia by many characters as follows according to the definition of Bruggmannia in Gagné (1994) : Macarangamyia has foursegmented palpi, well-developed labrum and labium, while Bruggmannia has three-segmented palpi, and a reduced labrum and labium; male flagellomeres of Macarangamyia have slight constrictions and short necks, in contrast to those of Bruggmannia , which have deep constrictions and long necks; ovipositor of Macarangamyia with strong setae dorsally and ventrally, but that of Bruggmannia only ventrally; aedeagus is cylindrical in Macarangamyia, but broad in Bruggmannia ; pupa of Macarangamyia has well-developed antennal and frontal horns and does not have abdominal dorsal spines, while that of Bruggmannia has undeveloped or weakly-developed antennal and frontal horns and two rows of dorsal spines; larva of Macarangamyia has a bidentate spatula, but Bruggmannia larva lacks a spatula. For these reasons we regard Macarangamyia as a new genus to science.

Figures

FIGURES 2–9. Macarangamyia itiokai n. sp. 2. Female head. 3. Dorsal view of the male terminal flagellomeres. 4. Ventral view of the female terminal flagellomeres. 5. Wing. 6. Tarsomere I. 7. Terminal tarsomere. 8. Terminal part of female abdomen. 9. Dorsolateral view of the terminal part of the ovipositor. Scale bars = 50 µm, except of figures 2, 5 and 8 = 200 µm.

FIGURES 10–12. Macarangamyia itiokai n. sp. 10. Terminal part of male abdomen, excluding male terminalia. 11. Male terminalia. 12. Ventral view of aedeagus. Scale bars = 50 µm.

FIGURES 13–15. Macarangamyia itiokai n. sp. 13. Larval spatula. 14–15. Pupal scanning electron micrographs 13. Scanning electron micrograph showing ventral view of head. 14. Scanning electron micrograph showing lateral view of anterior pupal segments. Scale bars = 100 µm, except of figure 13 = 50 µm.

FIGURES 16–17. Luzonomyia symphoremae Felt. 16. Ovipositor, the question mark indicates unclear and damaged part. 17. Dorsal view of male flagellomere V. Scale bars = 50 µm.