Johnsonomyia szadziewskii, Jaschhof, 2024

Jaschhof, Mathias, 2024, New taxa and new records of Winnertziinae and Porricondylinae (Diptera: Cecidomyiidae) from Germany, European Journal of Taxonomy 953, pp. 1-134 : 6-8

Johnsonomyia szadziewskii sp. nov.

urn:lsid:zoobank.org:act:04D870AA-91F7-4BB1-90C0-DB0A1DEC05F3

Fig. 1

Diagnosis

Morphology

Males of J. szadziewskii sp. nov. differ from those of congeneric species by several morphological characters in combination, as follows. The palpus is of ordinary size, i.e., not unusually thick ( Fig. 1A ); Rs is darkly tinted and thus markedly darker than other veins; the subtrapezoid ninth tergite has a nearly straight, unmodified posterior margin (↓ 1, Fig. 1C ); and the gonostylus, which is slightly flattened and markedly thicker basally than apically, has a slight swelling with microtrichia subapically below the apical tooth (↓ 2, Fig. 1D ). Females and preimaginal stages of J. szadziewskii are unknown.

DNA barcode

CO1 sequences (640‒658bp) of two of the three specimens detailed below were allocated to two BINs, BOLD:AEO8882 (holotype) and BOLD:AEM8765 (paratype ZSM-HYM-25591). Reexamination of the respective specimens failed to find morphological distinctions in support of the genetic clustering (distance 6.73%).A search in BOLDʼs BIN Database retrieved no further results for these BINs (accessed 25 Aug. 2023). CO1 sequences of J. palpata are unknown, and thus unavailable for comparison with J. szadziewskii sp. nov.

Etymology

This species is named in honor of Ryszard Szadziewski, professor emeritus of the University of Gdansk, Poland, and specialist taxonomist of Ceratopogonidae and other nematoceran Diptera .

Type material

Holotype

GERMANY • ♂; Bavaria, Lower Franconia, Rauhenebrach ; 49°91′82″ N, 10°56′03″ E; elev. 366 m; 12 Jul. 2019; LandKlif and J. Müller leg.; Malaise trap; BOLD GBDTA10278-21 ; ZSM-DIP-42307-B06 .

Paratypes

GERMANY • 1 ♂; Bavaria, Germaringen ; 47°96′30″ N, 10°67′62″ E; elev. 650 m; 16 Jul. 2019; LandKlif and J. Müller leg.; Malaise trap; ZSM-DIP-42307-B05 • 1 ♂; Bavaria, Weilheim, Pähl, Hartschimmelhof ; 47°93′87″ N, 11°18′63″ E; 20 Jun.‒12 Jul. 2020; D. Doczkal and K. Grabow leg.; Malaise trap; nutrient-poor meadow; BOLD GBCEC001-21 ; ZSM-HYM-25591 .

Other characters

Male

BODY LENGTH. 3.5 mm.

HEAD. Genal setae 15‒17, not clustered. Eye bridge dorsally 6‒7 ommatidia long. Scape concolorous with flagellum, with 1‒2 setae; pedicel slightly brighter, glabrous. Fourth flagellomere ( Fig. 1B ) with neck 1.1 × as long as node; node with whorl of subbasal setae intermingled with short hair-like translucent sensilla, a dense crenulate whorl of sensory hairs medially, microtrichia only basally (not illustrated). Palpus longer than head height, with 4 setose segments, first to third segments with sparse short hair-shaped translucent sensilla, first and second segments slightly thicker than third and fourth, fourth segment longest of all ( Fig. 1A ).

WING. Shorter than body. Length about 3.0 mm. Length / width ratio 2.9.

LEGS. Tarsomeres 2‒5 brighter than other segments. Claws slightly bent, untoothed. Empodia vestigial.

TERMINALIA ( Fig. 1D ). Gonocoxal synsclerite broader than long; ventral emargination deeply U-shaped, basally occupied by thin membrane devoid of vestiture; ventral bridge glabrous, its central portion darkly pigmented (presumably indicating presence of ninth sternite); medial bridges with conspicuously dense cover of short setae; posterior portions of dorsal apodemes strongly sclerotized and pigmented, anterior portions thick, with indistinct contours terminally, slightly longer than distance separating them. Gonostylus in ventral view 2.2 × as long as broad, with pointed apical tooth of moderate size. Tegmen roughly triangular; parameral apodemes strongly, remaining portions moderately sclerotized; apical portion slightly constricted, its surface uneven due to covering with tiny scales or knobs. Aedeagal apodeme thick, longer than tegmen, its apical and basal portions weakly contoured, with indistinct membranous, apparently funnel-shaped broadening apically. Both cerci and hypoproct densely microtrichose, cerci glabrous or with single seta posteriorly, hypoproct glabrous ( Fig. 1C , microtrichia not illustrated).

Differential diagnosis

In J. palpata , the only other European species of the genus, all four palpal segments were described as very robust and equally thick ( Mamaev 1966: fig. II.4), which clearly differs from the condition found in J. szadziewskii sp. nov. As a further distinction, the gonostylus of J. palpata was illustrated as evenly, strongly tapered towards the apex ( Mamaev 1966: fig. II.5; Spungis 1985: fig. 4.1). Mamaev (1968: fig. 4.2) described the ninth tergite of J. palpata as possessing a pair of microtrichose lobes at the posterior margin, while the ninth tergite of the new species is unmodified. In my opinion, it is more likely that those lobes constitute the distal portions of the cerci rather than a part of the ninth tergite (see the situation in J. szadziewskii , Fig. 1C ), which would render this putative difference irrelevant. Nearctic Johnsonomyia , especially J. fusca Felt, 1908 and J. rubra Felt, 1908 (type species), are generally similar to J. szadziewskii , although their terminalia differ in several details ( Jaschhof 2016b). Two species from the Russian Far East described as Johnsonomyia and later associated with Haplusia , H. pallida ( Mamaev, 1966) and H. obscuripes ( Mamaev, 1968) , differ from the species discussed above in that certain leg segments are decorated by apical clusters of dense, dark setae ( Mamaev 1966: fig. II.7).

Distribution

Ryszard Szadziewski (in litt., 6 Aug. 2021) provided me with sketches of the head and the terminalia of the male supposed to represent the only Polish record published of J. palpata ( Szadziewski 1976) . As is now obvious, the specimen was misidentified and actually belongs to the new species described here. Accordingly, J. szadziewskii sp. nov. is known from both Germany and Poland, and the only European occurrence of J. palpata is Latvia ( Spungis 1985). Since the westernmost distributions known of J. palpata, Kauguri and Dārzini in Latvia ( Spungis 1985), are only 450 km away from Toruń in Poland, the easternmost distribution known of J. szadziewskii , it is possible that the ranges of both species overlap.

Figures

Fig. 1. Johnsonomyia szadziewskii sp. nov., ♂♂. A. Head, lateral view, holotype (ZSM-DIP-42307-B06). B. Fourth flagellomere, lateral view, holotype. C. Ninth tergite, hypoproct and cerci, dorsal view, paratype (ZSM-HYM-25591). D. Terminalia, ventral view, holotype. Scale lines: A = 0.50 mm; B‒D = 0.05 mm. The numbered arrows indicate diagnostic characters (see text).