Euglossa amazonica Dressler, 1982b

Nemésio, André, 2012, Species of Euglossa Latreille, 1802 (Hymenoptera: Apidae: Euglossina) belonging to the purpurea species group occurring in eastern Brazil, with description of Euglossa monnei sp. n., Zootaxa 3151, pp. 35-52 : 37-38

Euglossa amazonica Dressler, 1982b

This species was recently recorded for the Atlantic Forest, from the states of Alagoas ( Nemésio 2010b) and Bahia ( Nemésio 2011a). Besides the latter record from Bahia (municipality of Uruçuca), in this review I found specimens of E. amazonica from the following localities in the state of Bahia ( Fig. 1 ): (i) Reserva Particular do Patrimônio Natural (RPPN) Fazenda Michelin (municipality of Igrapiúna); (ii) a forest remnant inside the campus of the ‘Universidade Estadual de Santa Cruz (UESC)’ (Ilhéus); (iii) Reserva Biológica (REBIO) Una (Una); (iv) RPPN Serra Bonita (Camacan); (v) Parque Nacional (PN) Monte Pascoal (Porto Seguro); (vi) a non-protected forest fragment of ca. 300 ha in Itamaraju; (vii) PN Descobrimento (Prado). Moreover, a single specimen was collected at RPPN Duas Barras, in Santa Maria do Salto, state of Minas Gerais. The occurrence of this species in Prado, the southernmost record of this species to date, extends its known geographic range in ca. 200 km southwards. No specimen was recorded in the state of Espírito Santo, in spite of the intensive sampling (ca. 4,000 specimens collected in 10 sampling sites distributed in five different forest remnants). It seems that the region of PN Descobrimento is the southern distributional limit of this species in the coastal Atlantic Forest. On the other hand, some specimens structurally indistinguishable from E. amazonica were collected in the region of Uberlândia, Minas Gerais (Silveira 2010), the westernmost part of the Atlantic Forest. Other orchid-bee species typical of the Amazon Basin, such as Euglossa decorata Smith, 1874 were also collected in this region (see Nemésio et al. 2007). Nevertheless, there is a huge gap between this population in Uberlândia and populations of northeastern Brazil here reported, in such a way future studies are needed to confirm the identity of all these populations.

Euglossa amazonica is not particularly rare where it occurs (ca. 70 specimens were collected in the forest remnants in the state of Bahia), but I noticed that it is more common in forest patches at the northern of its distribution, ranging from ca. 5% of the orchid-bee community in Igrapiúna to ca. 1% at PN Monte Pascoal, PN Descobrimento and adjacent areas. Also, a striking difference in bait preference occur along its range: it is strongly attracted to cineole and skatole, but its preference for skatole is apparently much stronger in the northern areas (unpub. data), whereas most bees collected at southern areas were attracted to cineole. A few specimens were also attracted to eugenol (mainly at the northern areas).

Euglossa amazonica is apparently associated to the best preserved forest patches in the Atlantic Forest ( Nemésio 2010b, 2011a, this work). If this is true, populations of this species in the Amazon and Atlantic forests are virtually isolated, since there remains no forested connection between both biomes. It is highly possible that both populations represent distinct species, but, contrary to other pairs of species recently split (e.g. Nemésio 2011b, d, and below in this work), specimens of both populations are very similar morphologically. Moreover, as mentioned above, a third population, found in the region of Uberlândia, should be also further investigated and only a thorough study comparing larger series of all populations can solve this matter.

Figures

FIGURE 1. Map showing the known geographic distribution (black circles) of Euglossa amazonica Dressler, 1982 b in the Atlantic Forest. Dark grey shadows correspond to the Atlantic Forest domain; light grey shadows correspond to “ Cerrado ” (Brazilian savanna) areas.