Cabamofa alexsmithi Jaschhof & Levesque-Beaudin, 2022

Jaschhof, Mathias & Levesque-Beaudin, Valerie, 2022, Cabamofa alexsmithi sp. nov., the second species of Cabamofa in Costa Rica (Diptera: Bibionomorpha: Sciaroidea incertae sedis), Zootaxa 5195 (2), pp. 196-200 : 196-199

Cabamofa alexsmithi Jaschhof & Levesque-Beaudin sp. nov.

( Figs 1–8 )

Differential diagnosis. Adults of the two Neotropical Cabamofa differ in vein M 1+2, which in C. alexsmithi resembles the shape of an U ( Fig. 4 ) whereas in C. mira the U has a short stem ( Jaschhof 2005: fig. 24). This distinction is stable among all the specimens known of both species ( C. alexsmithi , n = 5; C. mira , n = 3). Also, in some, but not all specimens known of C. alexsmithi vein CuA is slightly sinuous ( Fig. 4 ), not straight apically as in C. mira ( Jaschhof 2005: fig. 24). The two Oriental species of Cabamofa have a stemless M 1+2 and straight CuA ( Jaschhof & Ševčík 2019: fig. 2, Jaschhof et al. 2022: fig. 2). Otherwise the females of C. alexsmithi and C. mira are indistinguishable from each other, although the spermathecae of C. alexsmithi are partially covered with dense, tiny spikes, a structure not described for C. mira ( Jaschhof 2005) . Females of the Oriental species are unknown. Males of C. alexsmithi and C. mira differ in genitalic structures, notably the aedeagal apodeme, whose apex is pointed in C. alexsmithi ( Fig. 7 ) and furcate in C. mira ( Amorim & Rindal 2007: fig. 45), and the tegmen, whose posterior edge is markedly incised in C. alexsmithi ( Fig. 7 ) and only slightly concave in C. mira ( Amorim & Rindal 2007: fig. 45). Further possible distinctions in male genitalic structures are discussed below. Males of the two Neotropical Cabamofa are abundantly different from males in the Oriental region, for instance in having shorter flagellomeres ( Fig. 3 versus Jaschhof & Ševčík 2019: fig. 1) and markedly shorter apical palpal segments ( Amorim & Rindal 2007: fig. 39 versus Jaschhof & Ševčík 2019: fig. 3).

Discussion. There are likely further differences in male genitalic structures that could be used to distinguish C. alexsmithi from C. mira . For instance, the tegmen of C. alexsmithi has two pairs of hooks ventrally, which are largely transparent and thus not as obvious as Fig. 7 might suggest, whereas the tegmen of C. mira was illustrated as lacking any substructures ( Amorim & Rindal 2007: fig. 45). Also, the ninth tergite of C. alexsmithi is not as deeply incised posteriorly ( Fig. 6 ) as that drawn for C. mira ( Amorim & Rindal 2007: fig. 47), and the two species differ markedly regarding the outline of the hypoproct ( Fig. 6 versus Amorim & Rindal 2007: fig. 47). Finally, one may expect interspecific differences in the construction and setosity of the gonostylus, although those might be hard to recognize from illustrations; in C. alexsmithi , for instance, the three-lobed structure is so complex that different perspectives seem to show completely different gonostyli ( Fig. 5 versus Fig. 8 ). Also, one cannot be sure whether the gonostylar setae in C. mira are as uniform as illustrated by Amorim & Rindal (2007: fig. 46) or whether this is a result of the drawing technique.

Other characters. Male. Body length 2.7‒2.8 mm. Head. Clypeus setose. Scape slightly larger than pedicel, both setose, pedicel somewhat lighter in color than scape and flagellum. Fourth flagellomere short-cylindrical, with short neck; node 1.1 times as long as wide, with dense, irregular cover of fine seta-like sensilla, interspersed with very few larger setae arising from sockets, surface with irregular network of tenuous ridges ( Fig. 3 ). Compound eyes touching at vertex, eye bridge 5‒6 ommatidia long. Palpus short, with 5 setae-bearing segments, third segment conspicuously swollen, with sensory pit, fifth segment short, only slightly longer than fourth (similar to C. mira, Amorim & Rindal 2007 : fig. 39). Legs. Coxal lengths relative to thoracal height: forecoxa, 0.7, midcoxa, 0.6, hindcoxa, 0.5. Edge of foretibial anteroapical depression with comb of 12 straight, stiff setae; apices of mid- and hindtibia with combs of 4 and 15 setae respectively similar to those on foretibia but those on midtibia more widely spaced. Claws small, strong, crescent-shaped, toothless. Empodia barely claw-long. Wing ( Fig. 4 ). Slightly shorter than body, 2.7 times as long as wide. All veins clearly contoured, although some (M 1+2, Rs) are weaker than others. Abdomen ( Figs 1‒2 ). Segments 1‒6 normal size, tergite and sternite of a particular segment ending on same level; segment 7 considerably shorter than anterior segments, sternite twice as long as tergite; segment 8 similar to 7 but tergite still shorter and almost non-setose. Genitalia. Ninth tergite ( Fig. 6 ) large, subquadratic, outside with large setae, posterior edge with lateral tufts of short megasetae pointing inwards (ventrad). Gonocoxal synsclerite ( Fig. 5 ) with deep, U-shaped emargination ventroposteriorly, around the emargination setae of various sizes, a large non-setose portion ventroanteriorly; dorsal apodemes small, subtriangular; medial bridges densely setose (not illustrated). Gonostylus ( Figs 5, 8 ) with 3 lobes of different size, outline and setosity; apical lobe finger-shaped, with long setae; middle lobe roundish, its outside almost non-setose, inside densely setose, setae mostly strongly bent and relatively short; mediobasal lobe elongate, very densely covered in setae of various sizes, setae either bent or straight, all directed inwards (mediad). Tegmen ( Fig. 7 ) 1.8 times as long as broad, broadest at the midlength; parameral apodemes long and thin. Ejaculatory apodeme ( Fig. 7 ) nearly as long as tegmen, moderately sclerotized, markedly swollen subbasally. Cerci ( Fig. 6 ) small, halfmoon-shaped, with large setae. Hypoproct large, elongate-oviform, non-setose, densely microtrichose.

Female. Body length 3.2‒3.8 mm. Other characters are as in the corresponding males or indistinguishable from C. mira .

Molecular identification. COI sequences were obtained for all five specimens through the Canadian Centre for DNA Barcoding (CCDB: https://ccdb.ca/). Sequence lengths varied between 652‒654bp and collectively are publicly available in BIN: BOLD:AEL9580 ( Ratnasingham & Hebert 2013) for the Barcode of Life Data System (BOLD: http:// boldsystems.org/). This BIN and its barcodes are widely divergent from everything else on BOLD with the nearest neighbor being about 14% distant and matching the family Mycetophilidae (BIN: BOLD:ADV0335). This emphasizes the uniqueness of Cabamofa among Sciaroidea. Even within Cabamofa the divergence is wide, with a 19% distance to C. vietnamensis , the only other DNA barcode (BOLD) available for that genus. This suggests that the Neotropical species might be a different lineage than the Oriental species.

All data is publicly available on BOLD, its public dataset (dx.doi.org/10.5883/DS-CABAMOCR), and GenBank (https://www.ncbi.nlm.nih.gov/genbank/; accession: OM782492 - OM782496 ).

Etymology. Cabomofa alexsmithi was collected by a Malaise trap at 1200 m elevation in cloud forest on the Pacific slope of Volcan Cacao of Área de Conservación Guanacaste. It is named in honor of Dr. M. Alex Smith of the Department of Integrative Biology of the University of Guelph, Guelph, Canada, in recognition of his many years of intense documentation of the upper elevation ecology of the entomofauna of this volcano.

Type material. Holotype: male, Costa Rica, Área de Conservación Guanacaste, Guanacaste province, Sector Cacao, Derrumbe , 1220 m elevation, 10.929°N: 85.464°W, cloud forest, 03.xii.2015, Malaise trap, D. Janzen & W. Hallwachs leg. (sample ID: BIOUG71158 -F10, museum ID: CNC1156197 ) . Paratypes: 1 male, same data as for the holotype but 02.vi.2016 (sample ID: BIOUG70056 -B09, museum ID: CNC1156198 ) ; 3 females, same data as for the holotype but 17.xii.2015, 05.v.2016 and 19.v.2016, respectively (sample ID / museum ID: BIOUG68329 -G11 / CNC1156199 , BIOUG71132 -G03 / CNC1156200 , BIOUG71841 -C09 / CNC1156201 ) .

Figures

FIGURES 1–2. Cabamofa alexsmithi sp. nov., male paratype. 1: Habitus, lateral (specimen in ethanol after DNA extraction). 1A: Posterior abdomen including genitalia, enlargement from 1. 2: Ditto, dorsolateral. Scale for 1, 1.0 mm, for 1A and 2, 0.2 mm. Abbreviations: gen = genitalia, sg6 (‒sg8) = sixth segment (‒eighth segment), st7 (‒st8) = seventh sternite (‒eighth sternite), tg7 (‒tg8) = seventh tergite (‒eighth tergite).

FIGURES 3–8. Cabamofa alexsmithi sp. nov., males. 3: Third to fifth flagellomeres, lateral (paratype). 4: Wing, dorsal (holotype). 5: Genitalia, ventral (holotype). 6: Ninth tergite and adjacent structures, ventral (paratype). 7: Tegmen and aedeagal apodeme, ventral (holotype). 8: Gonostylus, dorsal (paratype). Scale for 3 and 5‒8, 0.05 mm, for 4, 1.0 mm.Abbreviations: cerc = cercus, hyp = hypoproct, sens = sensillum, tg9 = ninth tergite.