Erythrodiplax venusta (Kirby), an Amazonian species introduced into Minas Gerais, SE Brazil (Anisoptera: Libellulidae)

As referred by D.J. BORROR (1942, A revision of the libelluline genus Erythrodiplax [Odonut a], Ohio St. Univ., Columbus; — see also D.R. PAULSON, List of the Odonata of South America, by country, updated Oct. 2000, http://www.ups.edu/biology/ museum/ODofSA.html), the distribution of E. venusta encompasses the Amazonian parts of Venezuela, Surinam, Guiana, Bolivia, Peru and northern to western Brazil. Borror recorded Brazilian material from the states of Amapa (Macapa), Amazonas (Manaus, Santa Isabel), and Maranhao (Sao Luis); the southernmost tip of its distribution map reaching Mato Grosso (near Cuiaba). Examining ca 4000 Erythrodiplax specimens in the A.B.M. Machado collection (ABMM), we found 45 E. venusta specimens, which confirm the presence of the species in the state of Amazonas (Taracuä, Tabatinga) and are extending Horror's distribution map to the Brazilian states of Roraima (Boa Vista), Rondonia (Porto Velho) and Para (Belem, Tucurui, Jacareacanga). The examination of this material from all Brazilian states showed E. venusta to be restricted to the Amazonian region, thus not belonging to the fauna of Minas Gerais, a state that has been intensively collected, mainly by A.B.M. Machado and N.D. Santos, for about 50 years. It was surprising therefore, that on February 26 and April 9, 1994, 5 6 E. venusta were collected at the Sumidouro lake (municipalities of Pedro Leopoldo & Lagoa Santa, Minas Gerais, southeast Brazil, 19°32'05”S; 43°56'28”W), a locality situated as far as 1300 km from the hitherto known southernmost range of this species, in Mato Grosso. One of the collected specimens was in teneral condition. Between April 9 and May 5,1994, we searched for E. venusta at 10 other natural lakes in the Lagoa Santa region, but without success. Unsuccessful attempts were again made at the Sumidouro lake and its surroundings on April 13 and 18, May 15, September 21 and December 8,2000, at a time when E. venusta is on the wing at the Amazon region. On January 8, 2001 however, a single specimen was found there again. With a surface of ca 5 ha, the Sumidouro lake is situated on the Lagoa Santa Karst highlands, dominated by open farmland and the remnants of cerrado (Brazilian savanna) and deciduous forests. The water level varies considerably during the year, but at the time E. venusta was collected the lake was full and the shore pastures flooded. The local dragonfly community included: Aphylla theodorina, Brachymesia furcata, B. herbida, Cacoides latro, Coryphaeshna perrensi, Erythemis vesiculosa, E. plebeja, Erythrodiplax fusca, E. juliana, E. media, E. paraguayensis. E. umbrata, E. venusta, Homeura nepos, Idiataphe amazonica, Ischnura fluviatilis, Macrothemis lutea, Miathyria marcella, Micrathyria hesperis, Neoneura sylvatica, Oligoclada abbreviata limnophila, Orthemis discolor, Pantala flavescens, Perithemis mooma, Tramea abdominalis, s and T. cophysa. With the exception of E. venusta !, these species are common in the lentic systems of the karst region and most of them were present at the lake when visited by one of us (ABMM) in March 1975. At that time, no E. venusta was sighted. These circumstances indicate that this species has been introduced into the area not too long ago, and the question raised as to how it was transported there.