Pseudolycoriella tuakana, Köhler, 2019

Köhler, Arne, 2019, The genus Pseudolycoriella Menzel & Mohrig, 1998 (Diptera, Sciaridae) in New Zealand, Zootaxa 4707 (1), pp. 1-69 : 31-32

Pseudolycoriella tuakana sp. n.

( Figs 30–34 )

urn:lsid:zoobank.org:act:NomenclaturalActs/ 9392599F-A28F-4DCC-B7AF-C558BCBCFCEB

Material studied. Holotype male. New Zealand: North Island , Manawatu-Wanganui, Tongariro NP, Mangawhero River Valley 3 km NE Ohakune, altitude 690 m, mixed podocarp/broadleaf forest, Malaise trap, 26.11– 28.12.2002, leg. M. & C. Jaschhof & U. Kallweit ( NZAC, SDEI-Dipt-0001194) . Paratype. 1♂ same locality and same date as holotype ( SDEI, SDEI-Dipt-0001337) .

Description. Male. Head. Head capsule brown. Eye bridge three facets wide, two facets at margin. Scape and pedicel slightly paler than the flagellomeres; fourth flagellomere 2.8–2.9 times longer than wide; necks of flagellomeres well differentiated; surface of flagellomeres rough with deep pits, sensilla of two different lengths, small ones and longer, curved sensilla; setae on the flagellomere as long as flagellomere width, slightly curved. Maxillary palp long and three-segmented, first palpomere longest, second one shortest; first palpomere with an inconspicuous patch of sensilla and two to four long bristles, one of these bristles longer and more robust, located on the outer side. Prefrons and clypeus bulging. Thorax brown, concolourous with head; laterally extensively brighter. Posterior pronotum bare. Anterior pronotum with five setae. Episternum 1 with three to four setae. Mesonotum with four to five robust lateral bristles; row of dorsocentral bristles well developed; anteriorly on the mesonotum a patch of nine closely arranged arcostichal setae ( Figs 33–34 ). Scutellum with three to four robust bristles and several minor setae. Katepisternum as long as high. Wing. Length 2.7–2.9 mm; width/length ratio 0.39–0.40. Membrane transparent, slightly shaded and without macrotrichia, anal area present; all posterior veins distinct, except faint stem of M, apical third of R 5 with macrotrichia on ventral and dorsal side; bM and r-m bare (the paratype bears on the right wing setae on r-m), R 1 1.0–1.1 times as long as R; c/w ratio 0.77–0.80; r-m 1.1–1.3 as long as bM. Haltere long and sooty brown; shaft longer than knob. Legs pale brown, mid and hind coxae slightly darker than fore coxae. Tibial organ surrounded by a circular border and slightly narrower than half width of tibial apex; tibial organ consists of an irregular row of bristles. Front tibia without robust bristles among the vestiture (the holotype bears on the left tibia one bristle among vestiture). Mid tibia without bristles among vestiture. Posteriodorsal row of bristles very inconspicuous, consisting of two to three bristles.All tibial spurs equal in length. Claws with robust teeth. Abdomen brown, slightly paler than thorax, with long, dark setae. Hypopygium ( Fig. 30 ). Gonocoxites wider than long, inner side of gonocoxites with medium sized setae, outer side with long setae; ventral, inner side of gonocoxites basally not fused. Gonostylus elongate and curved, 2.9–3.0 times longer than wide, apex slightly differentiated, inner side of gonostylus concave and with scattered microtrichia; apex with one medium-sized spine that is only slightly longer than the surrounding setae ( Figs 30 & 31 ); one whip-lash hair present. Tegmen of the typical ground plan of the Psl. jejuna complex, onion-shaped but elongated, apical contraction broad; dorsal folds well developed; parameral apodemes basally strongly sclerotized, median connected, posterior branches of the parameral apodemes nearly parallel and close.Area of teeth absent. Ejaculatory apodeme dark, broad, and short; base of ejaculatory apodeme very delicate, long, and broad. Posterior portion of gonocoxal apodeme medium sized and brown, medially joined. Anterior portion of gonocoxal apodeme of medium length and dark brown.

Body size: 3.0– 3.2 mm.

Female. Unknown.

Genetic distances. Both available COI sequences are identical and do not show any p-distance. The nearest neighbour is Psl. dagae , diverging by a minimum of 5.93%. Both available 28S sequences are identical. The nearest neighbour is Psl. dagae , diverging by a minimum of 0.11%.

Etymology. The Māori word tuakana means elder brother or elder sister. Thus, the epithet refers to the close relationship of the new species to Psl. jejuna .

Distribution. New Zealand.

Discussion. Superficially Psl. tuakana is identical to Psl. jejuna and they would be regarded as conspecific, if the genetic analysis did not show a considerable difference between the species ( Fig. 61 ). Given that both type specimens of Psl. tuakana originated from the same collection locality as Psl. jejuna the existence of one single species with two distinct genetic variants is highly unlikely. A subsequent closer examination revealed some slight morphological differences. Nevertheless, these have to be interpreted carefully in the light of the small number of specimens of Psl. tuakana , which does not enable a robust statistical analysis. Pseudolycoriella tuakana does not have any bristles among the vestiture on the mid tibia; while 21 out of 22 specimens of Psl. jejuna bear one to two (exceptionally three) bristles on the mid tibia. The spine on the gonostylus is shorter in Psl. tuakana ( Fig. 35a ) and therefore does not protrude from the surrounding setae as in Psl. jejuna . Another difference is the longer ejaculatory apodeme in Psl. jejuna ( Fig. 35c ). Nevertheless, there are exceptions: one specimen of Psl. jejuna (SDEI-Dipt-0000588) has an aberrant short ejaculatory apodeme ( Fig. 27 ). The following weaker differences have more auxiliary character. The number of arcostichal bristles on the mesonotum differs between the species. Pseudolycoriella jejuna has two to seven arcostichal bristles while Psl. tuakana has nine ( Figs 28, 29, 33, 34 & 36 ). The length to width ratio of the gonostylus of both species might show different median values, but a huge overlap has to be considered ( Fig. 35b ). Additionally, the tegmen of most Psl. jejuna specimens is more rounded while the tegmen of Psl. tuakana is more tapered.

Figures

FIGURE 61. Phylogenetic tree of the New Zealand Pseudolycoriella species inferred from Maximum Likelihood analysis based on three concatenated genes (COI, 16S, and 28S; total length 3,053 bp) applying the model GTR+F+R4. Ultrafast bootstrap values (UFBoot; 1,000 replicates) are given if these values are greater than or equal to 95%. Intraspecific UFBoot values are not specified. Pseudolycoriella species without available genetic data are also inserted and assigned to a species complex according to the morphological results.

FIGURES 25–36. Pseudolycoriella jejuna complex, Pseudolycoriella jejuna (Edwards) and Pseudolycoriella tuakana sp. n. 25. Psl. jejuna (SDEI-Dipt-0000583), hypopygium. 26. Psl. jejuna (SDEI-Dipt-0000603), gonostylus. 27. Psl. jejuna (SDEI- Dipt-0000583), tegmen with aberrant ejaculatory apodeme. 28. Psl. jejuna (SDEI-Dipt-0000603), mesonotum. 29. Psl. jejuna holotype, mesonotum. 30. Psl. tuakana holotype, hypopygium. 31. Psl. tuakana paratype, gonostylus. 32. Psl. tuakana paratype, tegmen. 33. Psl. tuakana holotype, mesonotum (lateral view). 34. Psl. tuakana paratype, mesonotum (lateral view). 35a. Comparison of the length of gonostylar spine of both species; values for holotypes are indicated by black asterisks. 35b. Comparison of the length-width ratio of gonostylus of both species; values for holotypes are indicated by black asterisks. 35c. Comparison of the length of ejaculatory apodeme of both species; values for holotypes are indicated by black asterisks. 36. Histogram of arcostichal bristles of both species. Abbreviations:AC = arcostichal bristles; DC = dorsocentral bristles.