Scaptomyza exigua ( Grimshaw, 1901 )

Scaptomyza exigua ( Grimshaw, 1901) View in CoL

( Figs. 11–12 View FIGURE 11 View FIGURE 12 )

Drosophila exigua Grimshaw, 1901: 72 View in CoL .

Scaptomyza exigua Hardy, 1965: 688 View in CoL .

Diagnosis. Epandrium broad, with a broad and blunt posterior lobe, square-shaped. Surstylus is large and strongly curved in posterior view, small in lateral view. A row of four surstylar teeth is distributed in the dorsal portion of the surstylus. A few large and sparse bristles are found in the ventral portion of the surstylus.

Redescription. Male (n = 11). Head. Pedicel yellow and first flagellomere dark brown. Arista with 2 dorsal, 0 ventral, and about 5 short inner branches, plus terminal fork. Terminal fork deep, about 50% as long as basal segment of arista. Eyes dark red and face brown. Frontal vitta, in the region around the ptilinal suture is yellow, becoming brown in ground color and densely gray pollinose in the interorbital area. Frontal triangle, fronto-orbital plates, and ocellar triangle brown in ground color and densely gray pollinose. Anterior reclinate is inserted posterolaterally and halfway between the proclinate and posterior reclinate orbitals. Anterior reclinate 35% (27–40%) length of proclinate. Proclinate 81% (65–94%) length of posterior reclinate. Gena light brown in ground color and gray pollinose. Subvibrissal setae 53% (42–70%) length of vibrissae. Mouthparts yellow and palps yellow with 2 black apical setae. Thorax. Scutum densely gray pollinose, light brown in the anterior region, becoming darker posteriorly. Scutellum brown in ground color and densely pollinose. 2 pairs of dorsocentral setae. Acrostichal setae in 6 regular rows when counted between anterior dorsocentral setae, becoming sparse posteriorly. Basal scutellar setae divergent and apical scutellar setae cruciate. Pleura light brown in ground color and gray pollinose. 1 postpronotal and 3 katepisternal setae present. Anterior katepisternal setae 43% (26–53%) length of posterior katepisternal setae. Legs. Predominantly yellow. The front basitarsus is about 25% as long as the tibia. Wings. Hyaline without distinct pattern.

Abdomen. Predominantly dark brown. Male terminalia ( Figs. 12 View FIGURE 12 A-F). Epandrium broad, with a broad and blunt posterior lobe, square-shaped. No anterodorsal phragma or epandrial ventral lobe. Surstylus is large and strongly curved in posterior view, small in lateral view. A row of four surstylar teeth is distributed in the dorsal portion of the surstylus. A few large and sparse bristles are found in the ventral portion of the surstylus. Cerci undifferentiated. In lateral view, the cercal plates are two times higher than long. Measurements. TL = 1.21 (1.06–1.35) mm; WL = 2.48 (2.00–2.67) mm; TL/WL = 0.49 (0.46–0.53); HW/TL = 0.56 (0.50–0.62); CI = 3.44 (3.00–3.82); 4V = 1.47 (1.36–1.63); 5X = 1.69 (1.33–2.45); 4C = 0.68 (0.59–0.80); M = 0.47 (0.41–0.66).

Female (n = 10). Fits with the male in all characters. Anterior reclinate 47% (35–56%) length of proclinate. Proclinate 79% (66–88%) length of posterior reclinate. Subvibrissal setae 56% (39–68%) length of vibrissae.Anterior katepisternal setae 44% (36–61%) length of posterior katepisternal setae. Measurements. TL = 1.17 (1.10–1.26) mm; WL = 2.55 (2.44–2.67) mm; TL/WL = 0.48 (0.47–0.51); HW/TL = 0.55 (0.50–0.62); CI = 3.2 (1.27–3.78); 4V = 1.48 (1.38–1.56); 5X = 1.67 (1.47–2.00); 4C = 0.67 (0.59–0.78); M = 0.47 (0.41–0.58).

Distribution. Hawaiian Islands : Hawaiʻi, Maui, possibly Molokaʻi.

Ecology. This species uses bark, flowers, fruits, and leaves of native ʻōhā ( Clermontia spp. , Campanulaceae ) (Magnacca et al. 2008) and fruits of Hawaiian raspberry ( Rubus sp. , Rosaceae ) ( Heed 1968) as breeding sites.

Types. The holotype male (not examined) is deposited in the Natural History Museum (London).The homeotype male (not examined; UHIM2016.45348 ) is deposited in the University of Hawaiʻi Insect Museum .

Material Examined. 2 ♀♀ ( UHIM 2016.45351, UHIM 2016.45352), 1 undetermined sex (specimen in microvial, no UHIM accession code), South Kohala Mountains, Hawaiʻi, 3,700 ft. [ 1,128 m], 28 Jun 1966, reared ex Clermontia sp. ( Campanulaceae ) Fruits/Flowers, Stem/Leaves, G87A, W. B. Heed col. 33 ♂♂ ( UHIM 2016.4529, 45293, 45296, 45299–45301, 45304–45309, 45312, 45313, 45315, 45317, 45318, 45320–45322, 45325, 45329, 45330, 45333, 45334, 45337–45340, 45345–45348), 26 ♀♀ ( UHIM 2016.45292, 45294, 45295, 45297, 45298, 45302, 45303, 45310, 45311, 45314, 45316, 45319, 45323, 45324, 45327, 45328, 45331, 45332, 45335, 45336, 45341–45344, 45349, 45350), 1 undetermined sex ( UHIM 2016.45326), Puʻu Hualālai, Hawaiʻi, 01 Jul 1966, collected on Clermontia sp. ( Campanulaceae ) fruits, G90A, W. B. Heed col. 1 ♂ ( UHIM 2015.01214), Puʻu Hualālai, Hawaiʻi, 13 Jun 1966, reared ex raspberry fruit, G19A, W. B. Heed col. 1 ♂ (OG522.1.B), End of Tom’s Trail ( R Road), Stainback Highway, Waiākea Forest Reserve, Hawaiʻi, Cyanea sp. ( Campanulaceae ), 15 Jan 2009, P. M. O’Grady, J. Price, E. Young col.

Notes. This redescription was written based on 21 specimens that were deposited in the University of Hawaiʻi at Mānoa Insect Museum ( UHIM) as undescribed species. We recognized these flies as Scaptomyza exigua based on the redescription prepared by Hardy (1965) and comparison with non-type specimens from the UHIM and the O’Grady Lab ethanol collection. The habitus ( Fig. 11 View FIGURE 11 A-B) and male terminalia ( Fig. 12 View FIGURE 12 A-C) of these specimens were imaged and presented in this publication, in comparison to the specimens used for the redescription ( Figs. 11 View FIGURE 11 C- D, 12D-F) to demonstrate they correspond to the same species .