Schizomyia nodosa Felt

Kolesik, Peter & Gagné, Raymond J., 2020, A review of the gall midges (Diptera: Cecidomyiidae) of Indonesia: taxonomy, biology and adult key to genera, Zootaxa 4847 (1), pp. 1-82 : 63-65

Schizomyia nodosa Felt

[ Figs 37 a–p]

Schizomyia nodosa Felt, 1921b: 144 .

Material examined. Syntypes, male, two females, one pupa and three larvae were reared from Basilicum polystachyon (L.) Moench (as Moschosma polystachum [error for polystachyum] Benth). collected iv-1914 at Semarang, Java, Felt #a2099. The series is on three slides and uncleared. The male is entire, mounted laterally, with shrunken terminalia; the slide contains additionally a cecidomyiine male with tricircumfilar antennae, ignored by both Felt and us here. The females are missing some wings and tarsi, antennae are shrunken but appear entire, ovipositors are extended and visible. The pupa is partially damaged. Of the three larvae, one is entire with the terminal segment filled with debris, one consisting only of a head and a spatula, and one is parasitized with only the spatula observable.

Description. Adult. Wing R 5 bowed at distal third, joining C at wing apex, R 1 shorter than wing half, R S rudimentary, M 4 and Cu 1 forming fork. Palpus 4-segmented [ Fig. 37m ]. First tarsomere with small, straight ventro-apical lobe [ Fig. 37j ]. Tarsal claws simple, thin, bent at distal third, longer than empodia [ Fig. 37i ].

Male. Wing length 1.5 mm, width 0.6 mm. Flagellomeres 12, vaguely trinodal, circumfila strongly bowed [ Fig. 37k ], gonocoxite with triangular ventroapical lobe, bearing long setae at apex, gonostylus twice as long as wide, bent and blunt distally, uniformly setulose, tooth on gonostylus not properly visible on available specimen [ Fig. 37h ].

Female. Wing length 1.7 mm (1.7–1.8), width 0.6 mm. Flagellomeres 11 in both antennae of both available females, first and second fused, all with short necks, progressively shortened, with last flagellomere abruptly so, circumfila appressed to node [ Figs 37n, p ]. Ovipositor long, thin, flexible, with small dorsobasal lobe [ Fig. 37l ]; needle-like part about 6x longer than seventh sternite, bearing minute, medially appressed cerci visible, each with a single lateral seta [ Fig. 37o ].

Pupa. Length 1.8 mm. Antennal bases not produced, face without horns [ Fig. 37e ]; prothoracic spiracle long, about 10x longer than basal width, trachea ending at apex [ Fig. 37f ]; abdominal segments anterodorsally with large spiny spicules, otherwise mostly evenly covered with short spicules, on each side of terga a pair of closely set asetose papillae [ Fig. 37g ].

Larva. Length 2.1 mm. Spatula bilobed, lateral papillae comprising one pair of setose papillae and one triplet of two setose and one asetose papillae [ Fig. 37c ]; head with antennae 1.5x longer than wide at base, apodemes longer than head capsule [ Fig. 37b ]; cuticle of rounded verrucae throughout [ Fig. 37d ].

Remarks. The reduced number of flagellomeres to 11 in both females of S. nodosa is odd for this genus so might only be an aberration in this series. See under the heading of Schizomyia and under S. laporteae for characters that separate the three species of Schizomyia in Indonesia.

Biology. This species causes a flower gall on musk basil, Basilicum polystachyon (Lamiaceae) , described by DvLR & DvL (1926, gall No. 1324, Fig. 947 [ Fig. 37a ]). The calyx and the corolla are inflated, spheroid, about 5 mm across and have a rough surface. Anthers are atrophied but the pistil is swollen, inside of which a larva lives in a small cavity. Often all the flowers of an inflorescence are infected.

Geographical distribution. This species was found in Java ( Felt 1921b; DvLR & DvL 1926) at the following localities. Kemantran, near Tegal, ix-1909 ; Semarang , vii-1910 ; iv-1914 ; Tirto, near Pekalongan , vi-1911 ; Kuripan, near Pekalongan , vii-1911 ; Jrakah, near Semarang , viii-1912 ; Sayung, near Semarang , xi-1912 .

Figures

FIGURES 37a–p. Schizomyia nodosa: a, gall on Basilicum polystachyon (Fig. 947 of DvLR & DvL (1926)); b–d, larva: b, head (ventral); c, spatula with adjacent papillae; d, cuticle of 7th abdominal segment (ventrolateral); e–g, pupa: e, anterior segments (ventrolateral); f, prothoracic spiracle; g, 2nd abdominal tergum (dorsolateral); h–k, male: h, terminalia (lateral); i, tarsal claw and empodium; j, first tarsomere; k, 3rd flagellomere; l–p, female: l, postabdomen (lateral, arrow marks dorsobasal lobe); m, palpus; n, 3rd flagellomere; o. cerci; p, antenna.