Groveriella baltica Spungis & Jaschhof

Jaschhof, Mathias, 2017, Catochini, Strobliellini and Acoenoniini revisited: a taxonomic review of the small tribes of the Micromyinae (Diptera: Cecidomyiidae), Zootaxa 4250 (3), pp. 275-295 : 287-288

Groveriella baltica Spungis & Jaschhof

Fig. 7A–C

Groveriella baltica is known from Sweden, Estonia and Latvia, where a total of six males were found in the past ( Spungis & Jaschhof 2000; Jaschhof & Jaschhof 2009). Recent intensive collecting of Micromyinae in Sweden produced more specimens of this species, altogether seven males and five females. The females serve here to complement the male descriptions published earlier ( Spungis & Jaschhof 2000; Jaschhof & Jaschhof 2009).

Female description. Body size 2.8–5.1 mm. Head. Flagellomeres 22–25; nodes slightly more rounded compared with male, provided with, among other vestiture, sensory hairs arising from hooded alveoli, the latter scattered ( Fig. 7A ) or arranged in a line or girdle (arrow-marked in Fig. 7B ). Neck of fourth flagellomere same length as node or slightly longer; node with numerous hair-shaped translucent sensilla, one whorl of short setae basally, superior to it sensory hairs with hooded alveoli, one whorl of large setae medially ( Fig. 7A–B ). All palpal segments with translucent sensilla. Thorax. Antepronotal seta absent. Ovipositor ( Fig. 7C ) made up of structures posterior to seventh abdominal segment, short, about 1.5 times longer than seventh segment; all of eighth, ninth and tenth segments and cerci well developed, with normal setae of various sizes; gonocoxa 8 stout; sternite 9 (genital fork) sclerotized; basi- and disticercus indistinctly separated by pale double-seam. Two small, globular spermathecae, sclerotized, without membranous windows ( Fig. 7C ).

Discussion of female characters. Groveriella baltica is to my knowledge the only Micromyinae in which female flagellomeres have sensory hairs arising from hooded alveoli; those are otherwise confined to males where they are interlinked to form crenulate whorls (see, for example, Fig. 8D ). Presence of hooded alveoli in female Groveriella might be another differentiator from Strobliella . The double-seam separating the cerci is a conspicuous trait of G. baltica that might have merit in taxonomy, either for differentiating between the two species of Groveriella or as another distinction to Strobliella .

Material studied. Sweden: 4 males, 2 females (CEC406–411), Småland, Nybro, Bäckebo, Grytsjön NR, mixed old-growth taiga, 12 Aug.–6 Oct. 2014, MT, MCJ (in SDEI) ; 1 male, 1 female (CEC412–413), Öland, Mörbylånga, Stora Dalby forest NR, mixed broadleaf forest, 9 Aug.–3 Oct. 2015, MT, MCJ ; 1 female (CEC417), Mörbylånga, Vickleby ädellövskog NR, mixed broadleaf forest, MT, MCJ; 1 male, 1 female (CEC414–415), Öland, Borgholm, Lindreservatet NR, mixed broadleaf forest, 2 Oct.–23 Nov. 2015, MT, MCJ; 1 male (CEC416), Borgholm, Skepparsäng NR, mixed broadleaf / coniferous forest, 24 Aug.–1 Oct. 2015, MT, MCJ (all in NHRS). Estonia: 1 male (CEC418), Tartumaa, Maiorg near Annikoru, 25 Sep.–10 Oct. 2010, MT, O. Kurina & EMTP (in SDEI) .

Figures

FIGURE 7 A – C. Groveriella baltica, females (from Sweden). A: Fourth flagellomere, lateral. B: Fourth flagellomere, lateral. C: Ovipositor, lateral. Scales for A – B, 0.05 mm, for C, 0.1 mm.

FIGURE 8 A – E. Strobliella intermedia, males. A: Genitalia, ventral (specimen from Slovak Republic). B: Gonostylus, ventral (specimen from Sweden). C: Gonostylus, ventral (specimen from Sweden). D: Fourth flagellomere, lateral (specimen from Slovak Republic). E: Acropod of foreleg, lateral (specimen from Slovak Republic). Scales for A – D, 0.05 mm, for E, 0.025 mm.