Scaptodrosophila bryani ( Malloch, 1934:310 )

Mcevey, Shane F. & Polak, Michal, 2021, Drosophilidae (Diptera) of the Cook Islands, Records of the Australian Museum (Rec. Aust. Mus.) 73 (5), pp. 153-170 : 167

Scaptodrosophila bryani ( Malloch, 1934:310)

Figs 34–41

Of the two Scaptodrosophila species known from the Cook Islands, this one— S. bryani — is by far the most abundant: absent at only one of the 16 sites surveyed and the second most common species overall ( Table 2). Easily recognized by reference to the relative lengths of the scutellar setae: the basal pair are much shorter than the apical pair ( Fig. 41 ); males and females are similar in general appearance ( Figs 34–40 ); note that the katepisternal setae are large and subequal (indicated in Figs 36–37 ), a characteristic of many species of Scaptodrosophila but not one of Drosophila . Throughout the TSP reference to subequal katepisternal and unequal scutellar setae is an easy and reliable diagnostic for this species. However, Curran (1936) named a species that is, from a reading of his description, indistinguishable from S. bryani . Curran’s species Drosophila anuda (which he recognized as belonging in Paradrosophila Duda = Scaptodrosophila ] is known only from the very small “Anuda Island” [sic, possiblyAnuta Island –11.6120° 169.8496°, Fig. 1 ] and from the “Nupani Reef Island” (–10.0483° 165.7211° or –10.2340° 166.3100°) in the Santa Cruz Group of the Solomon Islands. Years of collecting in the TSP allows the generalization that if drosophilids are found at all on any remote or small island, especially on low sparsely vegetated islands, they will be one of the three most common species often associated with humans in or near dwellings at sea level: D. ananassae , D. sulfurigaster or S. bryani . An examination of the S. anuda (Curran, 1936) types series (5♂♂, 5♀♀) in the Museum of the California Academy of Sciences (Entomology) would be necessary to settle the question of whether or not it is a junior synonym of S. bryani .

Figures

Figure 1. Main islands or archipelagos of the Tropical South Pacific (TSP, above).The Cook Islands, as a country, includes Pukapuka coral atoll in the northern group; the present survey is restricted to the three large islands—Rarotonga, Aitutaki and Mangaia—of the Cook Islands southern group, boxed in blue above and enlarged below. Atolls and smaller islands in the Cook Islands southern group are named in grey below (see also Fig. 2 and Tables 1–3).

Figures 34–41. Scaptodrosophila bryani (Malloch), lateral views of males (34–37, K.393581–82, K.393583) and females (38–40, K.393585–87); anterior, middle, and posterior katepisternal setae (kepst s) indicated (36–37); detail of setae arising from scutellum (ap sctl s, apical scutellar seta, long; b sctl s, basal scutellar seta, short) and posterior part of scutum (41). All with label data: “COOK IS, Mangaia | –21.9531° –157.9148° | 7.ii.2017 ... fruit | Michal Polak” except Figs. 37 and 41: “NT Casuarina urban | 12.3731°S 130.8864°E | fruit compost 28.ix.2009 | S. McEvey & M. Braby”. All in AM.