Keys to the blow flies of Taiwan, with a checklist of recorded species and the description of a new species of Paradichosia Senior-White (Diptera, Calliphoridae)

Abstract Blow flies (Diptera: Calliphoridae) show a great diversity in behavior and ecology, play important roles in ecosystems, and have medical and forensic importance to humans. Despite this, the taxonomy and classification of Taiwan's Calliphoridae have rarely been studied. In this study, specimens of Taiwanese calliphorids were collected and carefully studied, and all 76 species recorded in Taiwan are listed following the identification keys. Dichotomous keys to all subfamilies, tribes, genera, and species of blow flies recorded in Taiwan are provided, including 16 species that are newly recorded from Taiwan. In addition, one new species of the genus Paradichosia Senior-White is described and illustrated. We also discuss the morphological differences between the specimens of Silbomyia hoeneana Enderlein collected from China and Taiwan, a species that has only been found previously in Southern China.


Introduction
Calliphorids show great diversity in behavior and ecology. Some species parasitize terrestrial vertebrates and invertebrates such as insects, snails, amphibians, mammals, and others rely on animal carcasses or excrement for survival (Kano and Shinonaga 1968). Some calliphorid species are regarded as serious pests because they carry pathogens or parasitize livestock or humans, causing myiasis (Tumrasvin et al. 1979;Sawabe et al. 2006). Other species called carrion flies are considered important scavengers due to their necrophagous feeding behaviors (Singh et al. 1979). Some species also provide an alternative way to estimate the minimum post-mortem interval of a victim or an animal in forensic investigations (Catts and Goff 1992). Adult blow flies often visit flowers, and some species like Chrysomya megacephala (Fabricius) are pollinators of fruits (Dag and Gazit 2001). The Calliphoridae are thus important in many different fields. In this article, keys to the subfamilies, tribes, genera, and species recorded from Taiwan are provided, hopefully to help in the understanding and identification of these useful flies in studies of medical entomology, forensic entomology, agricultural pollination, and other related fields.
Only fragmentary studies have been done on the taxonomy of Taiwanese Calliphoridae. Hennig (1941) listed 46 species of Calliphoridae from Taiwan. James (1977) mentioned 34 Taiwanese species in "A Catalog of Diptera of the Oriental Region." Kurahashi (1987a) published a key to the species of Taiwan's Calliphorini and Luciliini tribes. Fan (1992) published a key to the common calyptrate flies of China, including 40 Taiwanese species. Recently, a new Lucilia species, L. taiwanensis, was described by Kurahashi and Kano (1995).

Materials and methods
Adult specimens of Taiwanese calliphorids examined in this study were collected and pinned by the authors and colleagues, and additional specimens were collected by K. Kanmiya, R. Kano, K. Matsuki, and S. Ueno. Systematics and nomenclature adopted in this paper mainly follows Rognes (1991Rognes ( , 1997Rognes ( , 2002Rognes ( , 2009aRognes ( , 2009bRognes ( , 2011a, Fan (1992), and Kurahashi and Bunchu (2011). Specimens collected by the first author were mostly deposited in the Insect Museum of National Taiwan University (NTU). Other specimens were deposited in the National Museum of Nature and Science, Tsukuba (NSMT), Bishop Museum, Honolulu (BPBM), Carnegie Museum of Natural History, Pittsburgh (CMNH), and International Department of Dipterology, Tokyo (IDD). Some specimens are personal collection of Mr. K. Harusawa (PCKHa) as noted in the text. The terminology used in this study mainly follows that of Senior-White et al. (1940), Fan (1992), Triplehorn and Johnson (2005). Frons measurement and the calculation of the frons index follows Fan (1992).

Results and discussion
Examined specimens are classified into nine subfamilies: Ameniinae, Bengaliinae, Calliphorinae, Chrysomyinae, Luciliinae, Melanomyinae, Rhiniinae, Phumosiinae, and Polleniinae. In total, 76 calliphorid species are listed herein based on our direct examinations and the literature. Among them, 16 species are newly recorded from Taiwan, with an asterisk (*) preceding each of them in the checklist. The names in this checklist include mainly the species examined in this research and partially also the species recorded in the literature. Some species that have not yet been recorded in Taiwan are also included in this key with a footnote [e.g., 'not recorded from Taiwan']. We believe these latter species have the potential to be found in future Taiwan surveys because they occur in nearby areas of the Orient.

Key to the subfamilies of Taiwanese Calliphoridae
Wings: Brownish hyaline; veins brown; epaulet black, with black setulae and bristles; basicosta blackish; subcostal sclerite dark brown, yellowish pubescent; node of 2nd (R 2+3 ) and 3rd (R 4+5 ) longitudinal veins with a few black setulae above and below; 4th longitudinal vein (M 1+2 ) forming right angle; cell R 5 open in wing margin; section of 4th vein from bend to wing margin slightly curved inward; alar squama fuscous, paler at base with golden brown pubescence, semitransparent on apical part, with tuft of dark brown hairs at inner lower margin; thoracic one fuscous, lobulate bare on dorsal surface. Halter brownish, with yellowish apex.
Legs: Femora dark brown to black, tibia brownish, tarsi blackish; fore coxa dark brown to black, more or less whitish grey pollinose; mid and hind coxae brownish black, more or less whitish grey pollinose; fore tibia with 1 p and row of several short ad; mid tibia with 1 ad, 1 p, 2 pv, and 1 v; hind tibia with 3 ad, 2-3 pd, and 2-3 av.
Abdomen: Blackish, submetallic, with bronze tinge, slightly whitish grey pollinose, fine black median stripe more or less distinct on T 3 ; hairs and bristles black; T 1+2 with 2-4 lateral marginal bristles; T 3 with lateral and median mb; T 4 with row of mb; T 5 with row of mb and several discal bristles; ST 2 large, elongated, blackish, whitish gray pollinose except for margin, clothed in black hairs only; ST 3 and ST 4 with tuft of short hair as shown in Fig. 9G, H. ST 5 with lobes narrower and bended inward at tip as shown in Fig. 9C.
Hypopygium small in size, withdrawn from sight; genitalia as shown in Fig. 9A  Diagnosis. This new species, which has hairy eyes and a blackish scutellum, is similar to P. dubia (Malloch) from Java, Indonesia in general morphology. Nevertheless, it can be easily distinguished from P. dubia by having very short hairs on the tuft of ST 3 in the male.
Bionomics. Adults were found on the bush near the stream side. Distribution. Taiwan (Yilan).
Wings: Dark brown infuscate, most strongly brown along veins, paler in cells and to hind margin; veins dark brown; epaulet black, with black setulae and bristles; basi-costa black, with brown pubescence; subcostal sclerite dark brown; node of R 2+3 and R 4+5 veins with several black setulae extending to R 4+5 above and below; vein M 1+2 forming right angle; Cell R 5 open at wing margin; section of vein M 1+2 from bend to wing margin slightly curved inward; alar squama whitish, with pale yellow edge and white fringe; thoracic squama whitish, bare on dorsal surface, with dark brown edge and dark brown fringe. Halter fuscous, darkened on apex.
Legs: Femora dark brown to blackish, with metallic violet tinge; tibiae brown; tarsi dark brown; coxa dark brown to blackish, covered with black hairs and bristles anteriorly; fore tibia with row of several strong ad, 3 short pd, 2-3 strong p; mid tibia with row of several strong ad, several short pd, 2-3 strong p, 1 strong av; hind tibia with 2 av, row of several strong ad, 4 long pd.
Abdomen: Metallic bluish-green to blue, with somewhat purplish tinge, slightly silvery-gray pollinose; hairs and bristles black; T 1+2 with 1 lateral marginal bristle; T 3 with lateral and 1 pair of strong median mb, sometimes with 1 or a pair of median discal bristles weakly developed; T 4 -T 5 with row of mb; sternites dark brown with metallic violet tinge, covered with black bristles and hairs. Fifth sternite with long and wide lobes, longer than basal part, as shown in Fig. 10C.
Length: 12.0-17.0 mm. Diagnosis. The specimens of this species collected in Taiwan are slightly different in external morphology from those collected in China. Taiwanese specimens are more bluish when compared to the greener Chinese individuals, and the shape of the ST 5 is different (Fig. 11)