Research Article |
Corresponding author: Olavi Kurina ( olavi.kurina@emu.ee ) Academic editor: Burgert Muller
© 2022 Olavi Kurina, Aleksander Pototski.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kurina O, Pototski A (2022) Two new species of Phronia Winnertz, 1864 (Diptera, Mycetophilidae) from Taita Hills, Kenya. African Invertebrates 63(1): 89-103. https://doi.org/10.3897/afrinvertebr.63.86661
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Two new Phronia Winnertz, 1864 species—P. hannarostiae sp. nov. and P. ristoi sp. nov.—are described from Taita Hills in Kenya, representing the first named species of this genus in the African continent. The new species are morphologically similar to each other as well as to P. flobertae Matile – a species described from the Comoro Islands. These three species can be distinguished by details of the male terminalia, in particular by comparing the structures of the gonostyli. The new species are photographed and hand-drawn figures provided, and their taxonomy is discussed.
Afrotropical region, fungus gnats, Kenya, new species, Sciaroidea, Taita Hills, taxonomy
The genus Phronia Winnertz, 1864 was one of the first genera of fungus gnats (Diptera: Mycetophilidae) that was thoroughly studied in the 19th century. Namely, Henryk
As a member of the tribe Mycetophilini, the genus Phronia has anepisternum with strong bristles, whereas within the tribe, the distinguishing characters include bare anepimeron, short cubital fork, subcostal vein ending free and the costal vein extending at most very slightly beyond apex of R4+5 (e.g.
The current paper aims to describe two new species from Kenya, representing the first named Phronia species from the continental Africa.
The material was collected from Taita Hills in southern Kenya. The slopes of Taita Hills were formerly covered by moist montane forest of which only fragments are left, but these areas still accommodate a considerable diversity of species including endemic taxa (cf.
The material was collected by handpicking specimens from a ground level rock cavity (Fig.
The digital images of general habitus and terminalia were combined using the software LAS V.4.1.0. from multiple gradually focused images taken by a Leica DFC 450 camera attached to a stereomicroscope Leica 205C (see also
Phronia hannarostiae sp. nov. is closest morphologically to P. flobertae Matile, 1978 and P. ristoi sp. nov. but differs in characters of the male terminalia: gonocoxites anteroventrally with wide shallow incision; distal lobe of the ventral branch of the gonostylus elongated and stout; medial lobe of the ventral branch of the gonostylus sub-rounded with a strong long spine at dorsal margin medially; internal branch of the gonostylus bipartite, with ventral lobe apically widening, having combs of spines along posterior and dorsal margins, with dorsal lobe conical, having marginal lamellae; anterior branch of the gonostylus subrectangular, posteriorly somewhat widening, with four long setae subapically; aedeagal guides wide, narrower basally, rounded.
The species is named after Ms. Hanna Rosti (Helsinki, Finland), a PhD student of the University of Helsinki. Her study project includes research and conservation of nocturnal mammals of Taita Hills. She generously assisted and guided Mr. Risto Haverinen (Vantaa, Finland) and the junior author, collectors of the material, around the named area.
Male. Body length 3.1–3.2 mm (n = 4). Coloration. Head with vertex and frons brown, face and clypeus dark yellow, mouthparts yellow except palpus dark brown. Scape, pedicel and base of first flagellomere yellow, rest of flagellum brown. Thorax with scutum dull-yellow, having three longitudinal dull-brown strips, medial tapering posteriorly, ending before posterior margin; scutellum anteriorly brown, posteriorly yellowish to light brown; anepisternum, laterotergite and medial part of mediotergite brown, other thoracic lateral parts yellow. Thoracic setae brown. Wing hyaline, unmarked with slight yellowish tinge. Halter with stem yellow and knob brown. Legs yellow, hind coxa with lateral elongated brown macula, mid coxa with brown macula apically, hind femur entirely brown at apical fifth and brown dorsally at apical half, all tibiae with brown apical band, and tarsi yellow but seem darker because of dense brown setae. All setae on legs brown, tibial spurs brown. Abdomen brown, first 3–4 segments with large yellow anterolateral areas. Abdominal vestiture brown. Terminalia dark yellow. Head. Ocelli two, touching eye margins. Frontal furrow complete. Clypeus rectangular. Fourth flagellar segment about as long as wide, apical flagellar segment 2.2 times as long as wide basally. Flagellar segments with dense whitish setae about one third of segments’ width. Thorax. Scutum covered with setae, marginal setae stronger, two prominent prescutellar setae extending well over scutellum posteriorly. Scutellum with four strong marginal setae. Antepronotum with 4–5 strong and several weaker setae. Proepisternum with three strong and some weaker setae. Anepisternum with four strong setae at hind margin and several weak setae over surface. Katepisternum and anepimeron non-setose. Laterotergite setose with setae longer towards hind margin. Mediotergite non-setose. Wing. Length 2.88–3.00 mm, length to width 2.77–2.82. Sc, bm-m, m-stem and CuP non-setose, all other veins setose. C extending very slightly beyond apex of R4+5. Length of Sc measured from h 0.47 of r-stem. r-m about as long as m-stem. Posterior fork begins well beyond furcation of anterior fork, at the level of basal third of anterior fork, ratio of M2 to M4 2.7. Legs. Ratio of femur to tibia for fore, mid and hind legs: 1.11–1.29; 0.95–1.03; 0.84–0.93. Ratio of tibia to basitarsus for fore, mid and hind legs: 1.00–1.13; 1.30–1.48; 1.67–1.77. Fore tibia with a spur 2.25–2.57 times of tibial maximum width. Mid tibia with anterior spur 3.11–3.25 times and posterior spur 3.89–4.25 times of tibial maximum width. Hind tibia with anterior spur 2.55–3.22 times and posterior spur 3.27–3.89 times of tibial maximum width. Terminalia (Figs
Phronia hannarostiae sp. nov., male terminalia A terminalia, ventral view B terminalia, dorsal view with cerci detached C terminalia, lateral view D cerci and tergite IX E gonostylus, lateral view F gonostylus, internal view. Abbreviations: aed = aedeagus, aed gd = aedeagal guide, cer = cercus, gc = gonocoxite, gc pvm = posteroventral margin of gonocoxite, gst ab = anterior branch of gonostylus, gst db = dorsal branch of gonostylus, gst ibdl = dorsal lobe of internal branch of gonostylus, gst ibvl = ventral lobe of internal branch of gonostylus, gst vbdl = distal lobe of ventral branch of gonostylus, gst vbml = medial lobe of ventral branch of gonostylus, par = paramere, tg 9 = tergite IX. Scale bars: 0.1 mm.
Female. Unknown.
Holotype. Kenya • ♂; Taita-Taveta County, Taita Hills, Ngangao indigenous forest; 3.3642°S, 38.3410°E alt. 1930 m; 4 February 2022; A. Pototski & R. Haverinen leg.; hand-picked (pinned, terminalia in glycerin,
Matile provided figures of male terminalia of all described Afrotropical Phronia species from ventral view (
Phronia ristoi sp. nov. is closest to P. flobertae Matile, 1978 and P. hannarostiae sp. nov. but differs in characters of the male terminalia: gonocoxites anteroventrally with shallow U-shaped incision; distal lobe of the ventral branch of the gonostylus elongated, tapering, apically bent; medial lobe of the ventral branch of the gonostylus thumb-like, with a strong long sabre-like spine subapically; internal branch of the gonostylus bipartite, with ventral lobe conical, having a comb of lamellae along dorsal margin, with dorsal lobe bipartite, having marginal lamellae; anterior branch of the gonostylus posteriorly rounded, with 3–4 long setae subapically; aedeagal guides digitiform, apically pointed.
The species is named in honor of Mr. Risto Haverinen (Vantaa, Finland), a Finnish entomologist working mainly on macrolepidoptera. He was one of the collectors of the material of both species described in this paper and, additionally, contributed greatly towards successful fieldwork in Kenya.
Male. Body length 2.9–3.0 mm (n = 2). Coloration. Head with vertex and frons dark brown, face and clypeus dark yellow to light brown, mouthparts yellow except palpus dark brown. Scape, pedicel and base of first flagellomere yellow, rest of flagellum brown.
Thorax with scutum dull-yellow, having three anteriorly fused longitudinal dull-brown strips, medial tapering posteriorly, ending before posterior margin; scutellum dull brown; antepronotum and proepisternum yellow, other thoracic lateral parts dull brown, posterior margin of laterotergite darker. Thoracic setae brown. Wing hyaline, unmarked with slight yellowish tinge. Halter with stem yellow and knob brown. Legs yellow, hind coxa with lateral elongated brown macula, hind femur entirely brown at apical fifth and brown dorsally at apical half, all tibiae with brown apical band, and tarsi yellow but seem darker because of dense brown setae. All setae on legs brown, tibial spurs brown. Abdomen brown, first 3–4 segments with yellow anterolateral areas. Abdominal vestiture brown. Terminalia dark yellow to brown. Head. Ocelli two, touching eye margins. Frontal furrow complete. Clypeus rectangular. Fourth flagellar segment about 1.2 times as long as wide, apical flagellar segment 2.1 times as long as wide basally. Flagellar segments with dense whitish setae about one third of segments’ width. Thorax. Scutum covered with setae, marginal setae stronger, two prominent prescutellar setae extending well over scutellum posteriorly. Scutellum with four strong marginal setae. Antepronotum with four strong and several weaker setae. Proepisternum with three strong and some weaker setae. Anepisternum with 3–4 strong setae at hind margin and several weak setae over surface. Katepisternum and anepimeron non-setose. Laterotergite setose with setae longer towards hind margin. Mediotergite non-setose. Wing. Length 2.67–2.79 mm, length to width 2.53–2.65. Sc, bm-m, m-stem and CuP non-setose, all other veins setose. C extending very slightly beyond apex of R4+5. Length of Sc measured from h 0.50 of r-stem. r-m about 0.75 times as long as m-stem. Posterior fork begins well beyond furcation of anterior fork, at the level of basal third of anterior fork, ratio of M2 to M4 2.4. Legs. Ratio of femur to tibia for fore, mid and hind legs: 0.96–1.00; 0.91–0.94; 0.87–0.91. Ratio of tibia to basitarsus for fore, mid and hind legs: 1.00–1.04; 1.43–1.50; 1.73–1.80. Fore tibia with a spur 2.67 times of tibial maximum width. Mid tibia with anterior spur 3.00–3.57 times and posterior spur 4.29 times of tibial maximum width. Hind tibia with anterior spur 2.50–2.70 times and posterior spur 3.10–3.50 times of tibial maximum width. Terminalia (Figs
Female. Unknown.
Holotype. Kenya • ♂; Taita-Taveta County, Taita Hills, Ngangao indigenous forest; 3.3642°S, 38.3410°E; alt. 1930 m; 4 February 2022; A. Pototski & R. Haverinen leg.; hand-picked (pinned, terminalia in glycerin,
For distinguishing P. ristoi sp. nov. from P. hannarostiae sp. nov. see comments under the latter. Phronia ristoi resembles also P. flobertae Matile, 1978 as both species have distal lobe of ventral branch of the gonostylus evenly tapering posteriorly. However, P. ristoi has (1) the medial lobe of ventral branch of the gonostylus with strong sabre-like subapical spine, well discernible also from ventral view (without any spine in P. flobertae) and (2) the ventral lobe of internal branch of the gonostylus conical, in subequal length with the distal lobe of the ventral branch (subrectangular, about half length of the distal lobe of the ventral branch in P. flobertae).
Afrotropical fungus gnats (Diptera: Mycetophilidae) are rather superficially studied, with only about 10% of the real diversity known (
Taita Hills in Kenya constitute the most northeastern massive of the Eastern Arc Mountains (EAM) and the only section of this chain outside Tanzania. The EAM are known as the smallest and most fragmented biodiversity hotspots in the world (
We are much obliged to Ms. Hanna Rosti (Helsinki, Finland) and Mr. Risto Haverinen (Vantaa, Finland), who participated in fieldwork in Kenya, including collecting the specimens for this study. We are also thankful to Mr. Benson Mwakachola Lombo, a nature guide in the Taita Hills area, who assisted and led the team in the field. We are grateful to Peter Chandler (Melksham, UK) and Trude Magnussen (Oslo, Norway) for comments on an earlier draft of the manuscript.