Phthinia amorimi Fitzgerald

Fitzgerald, Scott J., 2017, Phthinia Winnertz (Diptera: Mycetophilidae): new species and records from the Neotropical and Oriental regions, Zootaxa 4231 (1), pp. 107-113 : 108

Phthinia amorimi Fitzgerald n. sp.

Figs. 1–2

Type material. Holotype: ♂ missing left front leg, glued directly to side of pin [CNCI], “Puerto Cisnes, 72°40’W. 44°45’S. Aysén, CHILE 1–15.II.61. Pena.” / “ HOLOTYPE, Phthinia amorimi Fitzgerald ” [red label], terminalia dissected . Paratypes: 1♂ [ SFC], same data as holotype ; 2 ♂♂ [ CNCI], same data as holotype except 16– 28.II.1961 .

Diagnosis. Phthinia amorimi can be distinguished from other Phthinia species by the following combination of characters: Sc short, not reaching level of Rs distally, ending just short of base of r-m; gonocoxites developed posteriorly beyond point of articulation of gonostylus into a pair of apically narrowly rounded, posteriorly-directed setose lobes, each with a large, strong, triangular medially-directed, dark, tooth ( Figs. 1–2 ); gonostylus elongate, apically bifurcate, the more anterior lobe apically rounded and spatulate, and the more posterior lobe fluted and complex ( Figs. 1–2 ).

Description. Male. Body length: approx. 4.5–6.0, 5.2 [4.5] mm (n=4). Coloration. Light brown; abdomen and head darker brown. Head. Three ocelli. Fourteen elongate flagellomeres; first flagellomere longer, approx. 1.3 times the length of flagellomere 2. Thorax. Laterotergite setose. Scutellum with numerous short setae and 2 longer, stronger setae apically. Legs. First tarsomere of foreleg approx. 2.3 times length of foretibia. Hind tibia with 1–5 minute anterior setae, 28–38 minute dorsal setae, and no posterior setae (n=4). Wings. 3.8–4.2, 4.0 [3.8 mm] (n=4). Membrane with dense macrotrichia and microtrichia. Sc short; not reaching level of Rs distally, ending just short of base of r-m. C extending about 1/4–1/3 of the distance between Rs and M1; r-m about 2.5 times as long as base of Rs; r-m slightly longer than stem of M (stem of M about 2/3 length of r-m); most of M1 weakly sclerotized and unpigmented (recognizable by crease and row of minute closely set setae present on other veins). A1 divergent from stem of CuA; distance between apex of A1 and CuA subequal to length of M stem. Abdomen. Terminalia ( Figs. 1– 2 ). Terminalia concolorous with abdomen to slightly lighter brown than abdomen. Cerci short, lobate, apically rounded, with small setae. Hypoproct short, medially divided and cerci-like, broadly rounded and densely setose apically. Gonocoxites ventrally entire (not partially subdivided by pair of sutures as in P. oliveirae ) ( Fig. 2 ). In dorsal and ventral views gonocoxites developed posteriorly beyond point of articulation of gonostylus into a pair of apically narrowly rounded, posteriorly-directed setose lobes, each with a large, strong, triangular mediallydirected, dark, tooth ( Figs. 1–2 ). Gonostylus elongate, apically bifurcate, the more anterior lobe apically rounded and spatulate, and the more posterior lobe fluted and complex ( Figs. 1–2 ). Parameres a pair of thin, weaklysclerotized, narrow, elongate, apically acute, divergent, saber-like lobes ventral to hypoproct ( Fig. 1 ). Aedeagal complex not easily distinguishable. Posterolateral edges of epandrium (T9) broadly rounded, without strong posteriorly-directed digitate lobes; T9 with a V-shaped cleft posteromedially that nearly subdivides sclerite ( Fig. 1 ).

Female. Unknown.

Comments. Phthinia amorimi is most similar to P. urubici Oliveira & Amorim, and P. theresae Oliveira & Amorim, from Brazil, and will key to couplet six (P. urubici / P. theresae) in the key to Neotropical species provided by Oliveira & Amorim (2010). However, the shape of the apically bifurcate gonostylus is quite different in P. amorimi , as is the presence of the large black triangular medially-directed tooth on the inner surface of the gonocoxites ( Figs 1–2 ). It is interesting to note that the structure of the terminalia and wing venation of P. amorimi allies this species with the two Brazilian species rather than any of the species currently known from Chile.

Etymology. The specific epithet honors Dalton de Souza Amorim for his work on numerous groups of Bibionomorpha and his contribution, both as a researcher and teacher, to the advancement of Neotropical Dipterology.

Figures

FIGURES 1 – 4. Male terminalia. Fig. 1 – 2. P. amorimi n. sp., [holotype male]; position and density of setae indicated by alveoli; apex of right gonostylus excluded for clarity. 1. Dorsal view. 2. Ventral view. Fig. 3 – 4. P. oliveirae n. sp., [holotype male] with one side completely excluded for clarity; position and density of setae indicated by alveoli. 3. Dorsal view. 4. Ventral view. Abbreviations: Gs, gonostylus; Gx, gonocoxites; T 9, tergite 9.