Ctenosciara alexanderkoenigi Heller & Rulik 2016

Heller, Kai & Rulik, Bjoern, 2016, Ctenosciaraalexanderkoenigi sp. n. (Diptera: Sciaridae), an exotic invader in Germany?, Biodiversity Data Journal 4, pp. 6460-6460 : 6460

Ctenosciara alexanderkoenigi Heller & Rulik 2016 sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: ZFMK-TIS-2527968 ; recordedBy: Björn Rulik; individualCount: 1; sex: male; lifeStage: adult; preparations: slide; otherCatalogNumbers: ZFMK-DIP-00011896; Taxon: scientificName: Ctenosciaraalexanderkoenigi; genus: Ctenosciara; specificEpithet: alexanderkoenigi; scientificNameAuthorship: Heller & Rulik, 2016; Location: country: Germany; countryCode: DE; stateProvince: North-Rhine-Westphalia; county: Cologne; municipality: Bonn; locality: Museum Koenig ; verbatimElevation: 67 m; decimalLatitude: 50.721944; decimalLongitude: 7.113611; Event: samplingProtocol: Malaise trap; eventDate: 07/06/2014; startDayOfYear: 155; endDayOfYear: 159; year: 2014; month: 6; day: 7; habitat: museum´s garden; Record Level: institutionCode: ZFMK

Description

Head. Eye bridge 2-3 rows of facets. Antenna with scape and pedicel brightened. LW-index of 4th antennal flagellar segment 2.65; neck 0.35 × the segment width (Fig. 2d); some pale sensillae present. Transition of basal part to neck pronounced. Neck unicolour. Antennal setae shorter than segment width; of normal strength; sparse; salient. Palpus bright; with three palpomeres. First palpomere of normal shape; with 2 bristles; with only some sparse sensillae, or with delimited sensillary field. Second palpomere short oval. Third palpomere as long as first segment. Thorax. Colour reddish, bicolour. Notum partially brightened. Thoracic setae long and strong, or normal; black. Mesonotum with some weaker central bristles. Posterior pronotum bare. Mesothoracic sclerites bare. Legs. Colour yellow-white. Hind coxa of same colour as femur. Hairs on fore coxa black. Front tibia apically with a distinct, delimited comb (Fig. 2e). Tibial comb undivided, with 7-8 bristles. Setae of front tibial organ bright. Front tibial organ distinctly bordered. Tibial setae on hind legs weak, inconspicuous. Tibial spurs of equal length. Claws untoothed. Wing (Fig. 2f). Slightly darkened; of normal shape. Wing membrane without macrotrichia. Wing venation weak, with faint stM. M-fork of normal shape. R1 ending clearly before base of m-fork; posterior veins with macrotrichia; stM bare; CuA1 with and CuA2 without macrotrichia; bM bare; r-m with a few setae; bM:r-M 1.1; st-Cu:bM 0.7; R1:R 0.47; c:w 0.7. Halter dark; of normal length. Abdomen. Abdominal setae strong and dense; tergal setae black; sternal setae black. Hypopygium (Fig. 2a) brighter than abdomen; 0.62 (0.55-0.70) × longer than wide. Base of gonocoxite with normal, weak hairs; gonocoxites fused; inner margin of gonocoxite narrowly U-shaped; inner membrane of hypopygium bare; elongated setae on valves of hypopygium absent. Gonostylus (Fig. 2b) elongate; 3.6 × longer than wide; Inner margin straight, or convex; apex tapered. Apical tooth present; as long or longer than subapical megasetae; ca. 5.6 × longer than wide; strong. Megasetae present subapically; number of megasetae 5; thick; curved; in one group; Posososition of basalmost megaseta 36 (32-40) % from top. Tegmen (Fig. 2c) nearly as long as broad; equally rounded; central process absent. Length of ejaculatory apodeme about 15 % of hypopygium; Aeadeagal apical structure absent. Field with aedeagal teeth present. Measurements. Body size ca. 2.2mm. Hind tibia length 1.05 mm. Wing length 2.0 mm.

Diagnosis

This beautiful species is conspicuous among the European species of Ctenosciara by its eye-catching and contrasting coloration (Fig. 3). Ctenosciara lutea is also colorful, but more or less completely orange, whereas Ctenosciara hyalipennis and Ctenosciara exigua are bright brownish just like many other Sciaridae . The male hypopygium conforms to the simple structure of the other European species, although the megasetae are more prominent. The new species also differs from all other European species in having a completely bare stM and CuA2 and a continuous, undivided tibial comb. The similar New Zealand species Ctenosciara nigrostyla (Mohrig, 1999) differs in having a less colourful hypopygium and a straighter gonostylus with a shorter apical tooth.

Etymology

The new species is named in honour of the founder of the Koenig museum in Bonn, Alexander Koenig (1885-1940).

Distribution

Besides the holotype, the species also appears to be present in New Zealand as confirmed by matching COI sequences on BOLD. We have not studied that material as of yet which is deposited in the Biodiversity Institute of Ontario, Canada.

Taxon discussion

After having seen the conspicuously looking Ctenosciara specimen from the museum's garden in Bonn for the first time, we were convinced of having discovered a new species native to Europe. The yielded COI sequence showed a 7% distance on BOLD to the nearest neighbour from Australia and convinced us furthermore of having an unknown species. After submitting the sequence to BOLD, it was shown to be identical to two other also newly submitted sequences from New Zealand, sharing the same BIN BOLD:ACP7364. Initially having consulted the key to the New Zealand species ( Mohrig and Jaschhof 1999), we were inclined to identify our specimen as Ctenosciara nigrostyla Mohrig but a comparison with the type material in the collection of Werner Mohrig (Poseritz, Germany) revealed that the two species are in fact different. A worldwide DNA database like BOLD does not only help to distinguish new and cryptic species, but may also show distribution patterns. Usually more competitive continental species disperse on islands like New Zealand, but apparently the inverse case is also possible. It is a rare occurrence, that a species from the opposite end of the world is represented by a single specimen only and it is not yet clear, whether Ctenosciara alexanderkoenigi has a permanent population in Germany or if it was only introduced casually with plants or soil. Probably the species was recently introduced from the Australasian Region. If it was a permanent member of the European fauna, a striking species like this would likely have been found earlier.