Eosphaerophoria marginata Frey, 1946

Mengual, Ximo, 2013, Notes on Citrogramma Vockeroth and Eosphaerophoria Frey (Diptera: Syrphidae), Zootaxa 3745 (3), pp. 388-396 : 394-395

Eosphaerophoria marginata Frey, 1946

Eosphaerophoria marginata Frey, 1946 . Not. Entomol., 25 [1945]: 169. Lectotype: m, Philippines: Luzon, Mt. Banahao [MZH, Helsinki] designated by Mengual & Ghorpadé 2010; Knutson et al. 1975: 313, cat. cit.; Claussen & Weipert 2003: 354, figs; Mengual & Ghorpadé 2010: 63, descr., figs, key.

Mengual & Ghorpadé (2010) re-describe the male and female of E. marginata , and provide an identification key and figures of wing, thorax, abdomen, and male genitalia.

While visiting the IRSNB, a female specimen of E. marginata from Vietnam was found. This represents the first published record of this genus for 20 years, and the most recent individual of E. marginata collected during the last 30 years. It also extends the distribution area of this species from the Philippines and Thailand to Vietnam. The number of Eosphaerophoria species from Vietnam in increased to three, other species occurring are E. symmetrica Mengual in Mengual & Ghorpadé, 2010 and E. vietnamensis Mengual in Mengual & Ghorpadé, 2010.

Mengual & Ghorpadé (2010) state that nothing is known about the biology of Eosphaerophoria , except that Keiser (1958: 204) collected his specimen in the grass in a swampy locality. They also state that more species and specimens might be found in the future, especially when using Malaise traps. In fact, this new E. marginata specimen from Vietnam was collected with a Malaise trap at Nui Pia Oac Nature Reserve , which was decreed as a nature reserve in 1986, centred on Mount Pia Oac , 1,931 masl (Tordoff et al. 2000). Nui Pia Oac Nature Reserve supports low, medium and high altitude montane broadleaf evergreen forests (Tordoff et al. 2000). The new specimen of Eosphaerophoria was collected near the summit of the Mount Pia Oac , in a clearing of high altitude montane evergreen forest (J. Constant, personal communication), a habitat clearly differing from the swampy locality of Keiser (1958).

Interestingly, the female from Vietnam shares the abdominal pattern with the female from Thailand, which is a bit different from the abdominal pattern of the female paratype from the Philippines (see Mengual & Ghorpadé 2010: 58, Figs. 40–41). Mengual & Ghorpadé (2010) state that more material will be needed to re-assess the status of the E. marginata population outside the Philippines. Nothing more can be strongly affirmed, but females from Vietnam and Thailand share a common abdominal pattern, which is slightly different from the one of the paratype females.

Material examined. 1 female, ‘ VIETNAM: Pia-Oac / Mt. NR (Malaise Trap) / 22°36'N 105°53'E / 04– 06.viii.2010 / Leg.: J. Constant & / P. Limbourg I.G.31.668’ [IRSNB].