Three New Species of Shoot Fly, Atherigona spp., from Northern Thailand

Three new species of shoot fly, Atherigona Rondani (subgenus Acritochaeta Grimshaw) (Diptera: Muscidae), are described from northern Thailand, based on morphological characteristics of males. Unique features of A. komi sp. n. include a distinct spiral groove on the dorsal aspect of the fore femur and two dark apical wing spots, whereas A. chiangmaiensis sp. n. is recognized by the presence of one large patch on the apical wing spot, appearing as a large and smaller wave-shaped patch, and no distinct pattern on tergites. A. thailandica sp. n. displays a remarkable dark boomerang-shaped patch along the wing margin and fore femur, with two rows of long hairs on the dorsal surface. Male terminalia are also different in the new species, showing distinctive characteristics. This paper also presents five newly recorded species in Thailand; Atherigona maculigera Stein, Atherigona ovatipennis vietnamensis Shinonaga et Thinh, Atherigona pallidipalpis Malloch, Atherigona seticauda Malloch, and Atherigona setitarsus Shinonaga et Thinh. A key is provided for the adult males of Atherigona recorded in Thailand, all belonging to the subgenus Acritochaeta, except for A. soccata Rondani.


Introduction
The shoot flies, Atherigona Rondani (Diptera: Muscidae), are small Diptera of the Muscidae family that are widely distributed in Old World tropical regions. Taxonomy of these flies has been investigated in Nepal (Pont 1972;Shinonaga and Singh 1994), the Philippines (Pont and Magpayo 1995), Vietnam (Shinonaga and Thinh 2000), and Borneo Island (Shinonaga 2009), but little investigative work has been done in Thailand. Sepsawadi et al. (1971) investigated the control of Atherigona soccata Rondani (subgenus Atherigona), which is the most economically important pest of sorghum. Pont and Magpayo (1995) studied the subgenus Acritochaeta Grimshaw, whose larvae act as scavenger or predators of decaying organic matter. Atherigona orientalis Schiner, a mechanical carrier of helminthic eggs and larvae, was reported in Brazil (de Oliveira et al. 2002); research conducted in China included A. orientalis, A. simplex (Thomson) and Atherigona sp. in the list of flies frequently associated with carcasses, suggesting possible forensic importance (Shi et al. 2009).
A large number of flies in the genus Atherigona were collected during the course of a faunistic study of flies with medical and/or forensic importance in Northern Thailand during 2009-2010; 1-day-old rotten spoiled beef viscera was used as bait. Using keys for identification (Shinonaga and Singh 1994;Pont and Magpayo 1995;Shinonaga and Thinh 2000), these collections revealed three species that had never been described, belonging to the subgenus Acritochaeta. These three species are new to science, based on the morphological difference of males from previous investigations. Furthermore, five species of Atherigona were recorded for the first time in Thailand. The primary aim of this paper is to describe three new species based on the peculiar characteristics of males. For comprehensive comparison among all species of Atherigona recorded in Thailand, unique characteristics and male terminalia of all available species, along with a key for male identification, have been included.

Materials and Methods
The fly specimens described herein as a new species were collected in 2009-2010. Oneday-old rotten spoiled beef viscera (300g) were used as bait, and sweeping nets and traps (30 30 50 cm) were used to capture individuals. The beef viscera were left at room temperature (~ 25-30 °C) 24 hours before use. After identification using keys of Shinonaga and Singh (1994), Pont and Magpayo (1995), and Shinonaga and Thinh (2000), these species were identified as new to science. Males were examined under a dissecting microscope (Olympus, www.olympusglobal.com) to identify external morphological features such as the wing, leg, and abdomen. Photographs of the whole body, wing, and abdomen were taken with a Nikon E-800 (Nikon, www.nikon.com), and Adobe Photoshop CS3 was used to adjust the brightness and contrast of the images.
To examine the terminalia, the last abdominal segment of the specimens that had already been taken for photographs was dissected under a dissecting microscope (Olympus) using fine forceps. To clear the integument, 10% potassium hydroxide solution with one drop of 70% ethanol was used to soak the specimens for 24 hours before a thorough examination. The terminalia were transferred onto a microscopic slides containing a few  McAlpine (1981), and male terminalia follows Sinclair (2000). Specimen depositories are cited using the following abbreviation: NSMT, National Science Museum, Tokyo.

Diagnosis
Because of its elongate palpus ( Figure 1A), lack of hypopygial prominence, and lack of a trifoliate process at end of the epandrium, this new species was grouped in the subgenus Acritochaeta. Distinctive traits of the male of Atherigona komi include a distinct spiral groove on the dorsal aspect of the fore femur ( Figure 1B) and two dark apical wing spots (Figures 1C,2A,3A). This new species is closely related to A. ovatipennis vietnamensis Shinonaga et Thinh reported from Vietnam (Shinonaga and Thinh 2000) by the similarity of abdominal pattern on all tergites ( Figure  5B). However, distinctive characteristics used to differentiate between these two similar species are the (1) two large dark wing spots located at vein R 2+3 and M in A. komi (Figures 1C,2A,3A), while only one small dark spot located between vein R 2+3 and M is seen in A. ovatipennis vietnamensis ( Figures 3B, 7B), the (2) fore femur; the presence of spiral groove on dorsal surface in A. komi ( Figure  1B) but absence in A. ovatipennis vietnamensis, the (3) fore tibia; the presence of long bristles curled at apices on basal and distal parts in A. ovatipennis vietnamensis ( Figure 7A), but absence in A. komi ( Figure  1B), and the (4) fore tarsus; the enlarged pulvillus and empodium in A. ovatipennis vietnamensis ( Figure 7A), but normally sized in A. komi ( Figure 1B).
Head. Eyes bare and dichoptic. Frontal vitta black with orange apical , in two specimens with dark orange, in one specimen with wholly black (Table 1). Fronto-orbital plate grey pollinose. Antennal scape, pedicel, and postpedicel entirely black. Arista pubescent dark brown with light brown at basal . Palpus wholly black, elongated with slight dilation at apex, with fine hairs along apical ventral part and two strong hairs anteroventrally ( Figure 1A).

Remarks
This species was collected in traps (30 30 50 cm) with 300 g of one-day-old rotten spoiled beef viscera, not one-day-old rotten spoiled mackerel.

Distribution
Known only from the type locality, Chiang Mai and Phitsanulok provinces of Thailand.

Bionomics
Adult males were collected using one-day-old rotten spoiled beef viscera or one-day-old rotten spoiled pork viscera as bait, at altitudes ranging from 805-1104 m. The collection site was the bush with the high tree along the local highway ( Figure 8A). This species was collected from the late rainy season (September) to early winter (November).

Etymology
This new species was named in honor of Dr. Kom Sukontason for his support and encouragement of fly research in Thailand.

Diagnosis.
This new species was placed in the subgenus Acritochaeta for having an elongate palpus ( Figure 9A); presence of dark apical wingspot ( Figure 3C); no hypopygial prominence; and without a trifoliate process at the end of the epandrium. Males of A. chiangmaiensis can be recognized by the presence of one large patch on the apical wing spot ( Figure  3C) appearing as a large and smaller waveshaped patch ( Figure 9B), an orange body ( Figure 4C), and no distinct pattern on tergites ( Figures 5C, 9C).
Head. Eyes bare and dichoptic; frontal vitta orange that is basally dark; fronto-orbital plate grey pollinose. Antennal scape and pedicel orange; postpedicel black; arista pubescent, black with orange at basal . Palpus wholly black, elongated with slight dilation at apex, with fine hairs along ventral part and strong hairs along dorsal part ( Figure 9A).

Taxonomic Discussion
A. chiangmaiensis sp. n. is a member of the subgenus Acritochaeta based on the presence of a dark apical wing-spot, an elongate palpus, lack of a hypopygial prominence, and lack of a trifoliate process at the end of the epandrium. This new species is closely related to A. gigantipunctata Shinonaga reported from Vietnam (Shinonaga and Thinh 2000) by the similarity of the abdominal pattern, which lacks any patterns or marginal bands, as well as the similarity of one large dark spot from midway between veins R 2+3 and R 4+5 to just beyond vein M. However, the shape of this wing spot is markedly different between these two species; a large and smaller wave-shaped patch is seen in A. chiangmaiensis, compared to a vertical oval patch seen in A. gigantipunctata.

Distribution
Known only from the type locality, Chiang Mai province, Thailand.

Bionomics
Adult males were collected using one-day-old rotten spoiled beef viscera or one-day-old rotten spoiled pork viscera as bait, at an altitude of 1142 m. Specimens were unable to be collected using one-day-old rotten spoiled mackerel. The collected site was the dense forest ~ 200 m away from the local highway ( Figure 8B). This species was collected only in the late rainy season (September) to early winter (November).

Etymology
The new species epithet refers to Chiang Mai province, in which the type of material of the new species was collected.

Diagnosis
This new species is placed in the subgenus Acritochaeta for having an elongate palpus ( Figure 10A), the presence of a dark apical wing-spot ( Figures 3D, 10C), lack of a hypopygial prominence, and lack of a trifoliate process at the end of the epandrium. Males of A. thailandica can be recognized by the presence of a dark boomerang-shaped patch along the margin, extending from the distal between veins R 1 , R 2+3 to just below vein M ( Figures 3D, 10C), cross vein r-m at the middle of cell dm, and fore femur with two rows of long hairs on the dorsal surface.
Thorax. Ground-color grey with three black longitudinal stripes of the same width ( Figure  4D); apex of scutellum orange; postpronotal lobe yellow; anterior and posterior spiracle yellow; basal lateral scutellar setae almost half as long as subbasal lateral setae. Chaetotaxy of scutum: acr in 3 or 4 rows at suture; dc 0+5-6; ial 1+1; pprn 1; npl 2; kepst 3. Leg with orange coxae and trochanters; foreleg almost completely black, except orange at basal -of femur and on basal of tibia; fore femur with two rows of long hairs on dorsal surface; mid leg entirely orange; mid femur entirely orange, with 2 p; hind leg almost orange, except darker at tip and femur and tibia, respectively; hind tibia with 1 ad, 1 av, 1 pd. Wing hyaline with dark boomerang-shaped patch along the wing margin, extending from distal between veins R 1 and R 2+3 to just below vein M ( Figures 3D, 10C); M slightly bending anteriorly; cross vein r-m at the middle of cell dm. Lower and upper calypters yellowishwhite. Knob of halteres white.

Taxonomic Discussion
A. thailandica can be distinguished from the other species of the subgenus Acritochaeta for having unique wing features; a dark boomerang-shaped patch along the wing margin, extending from distal between veins R 1 and R 2+3 to just below vein M. The other characteristics are the position of a cross vein, of which r-m at the middle of cell dm and fore femur with two rows of long hairs on dorsal surface.

Bionomics
Adult males were collected using one-day-old rotten spoiled beef viscera as bait, at altitudes ranging from 805-1104 m. However, they could not be collected using one-day-old rotten spoiled pork viscera or one-day-old rotten spoiled mackerel as bait. The collection site was the bush with the high tree along the local highway ( Figure 8A). This species was collected only in the late rainy season (September) to early winter (November).

Distribution
Known only from the type locality, Chiang Mai province, Thailand.

Etymology
The species epithet refers to Thailand, where the type material of the new species was collected.

Distribution
Vietnam (Shinonaga and Thinh 2000) and Thailand (new record). The collection sites in Thailand were in an urban area, altitude ranging from 805-1494 m.

Distribution
Philippines, Malaysia, Sri Lanka, Sulawesi, Sumatra, Taiwan (Pont and Magpayo 1995), and Thailand (new record). The collection sites in Thailand were in an urban area, altitude ranging from 334-1142 m.

Atherigona (Atherigona) soccata Rondani
No specimens were collected in this study; however, there was a record for this fly control in Thailand (Sepsawadi et al. 1971).

Distribution
Pakistan, India, Nepal, Myanmar, China (Guangdong), Philippines, Thailand, southern Europe, North Africa, Middle East, throughout the Afrotropical region (Pont and Magpayo 1995) Key to the species of Atheriogona recorded in Thailand (only for males)