Euglossa (Euglossella) polita Ducke

Hinojosa-Díaz, Ismael A. & Engel, Michael S., 2014, Revision of the orchid bee subgenus Euglossella (Hymenoptera: Apidae), Part II: The viridis and mandibularis species groups, Journal of Melittology 36, pp. 1-108 : 45-51

Euglossa (Euglossella) polita Ducke

( Figs. 60–66 , 149 , 159 , 170 )

Euglossa polita Ducke, 1902a: 402 [♂ ♀]. Lectotype ♂ (MPEG, visum).

DIAGNOSIS: Labiomaxillary complex in repose reaching anterior half of second metasomal sternum; upper and lower interorbital distances subequal (lower distance at most 8% wider than upper) ( Fig. 62 ); malar area short (less than 0.25 mm, or noticeably shorter than diameter of mid-flagellar articles) ( Fig. 62 ); pronotal dorsolateral angle projected as a lamella; mesotibial tufts as follows: anterior tuft rhomboid, long (maximum length exceeding mid-width of velvety area) and noticeably wide (mid-width exceeding width of contiguous section of velvety area), posterior tuft oblong oriented diagonally ( Figs. 63 , 149 ); mesobasitarsal posterior keel acutely projected ( Fig. 66 ); second metasomal sternum with two conspicuous cowled slits covering setose tufts ( Fig. 65 ); width of metasoma and head only marginally different (less than 1.05 times) ( Fig. 60 ); head mainly green with some blue areas ( Fig. 62 ); paraocular marks trapezoidal, lower width about two thirds of length of lower lateral part of clypeus ( Figs. 61–62 ); scape with ivory spot covering almost entire anterior surface ( Fig. 62 ); mesosoma (except mesoscutellum) mainly dark green with blue-purple intergradations and bronzy iridescence ( Figs. 60–61 ), mesoscutellum blue-purple ( Fig. 60 ); first to third metasomal terga mainly cyan-blue, remaining terga progressively green ( Figs. 60–61 ); mesoscutellum with large sparse (as compared to other species) punctures (separated by one to one and a half puncture diameters) ( Fig. 60 ); central area of mesepisternum with punctures separated by at least one puncture diameter ( Fig. 61 ); metasomal terga densely and evenly imbricate-punctate ( Figs. 60–61 ); mesosomal vestiture dominated by pale-fuscous setae ( Figs. 60–61 ); eighth metasomal sternum posterior section very narrow as a slender cylinder; gonocoxite dorsal process about as wide as long ( Fig. 159 ); gonostylar lateral section with well-developed “secondary” lobe (convexity of posterior margin of basal sector) almost as long as adjacent ventral lobe, covered with dense setae reaching posterior margin of blades of penis valve.

DESCRIPTION: ♂: Structure. Total body length 11.59 mm (11.11–12.07; n=2); labiomaxillary complex in repose reaching anterior half of second metasomal sternum ( Fig. 61 ). Head length 2.76 mm (2.74–2.78; n=2), width 4.79 mm (4.76–4.81; n=2); upper interorbital distance 2.03 mm (1.94–2.11; n=2); lower interorbital distance 2.19 mm (2.11– 2.26; n=2); upper clypeal width 1.26 mm (1.19–1.33; n=2); lower clypeal width 2.09 mm (2.07–2.11; n=2); clypeal protuberance 0.52 mm (n=2); clypeal ridges, labral ridges, and labral windows as described for E. viridis ; labrum wider than long, length 1.04 mm (n=2), width 1.26 mm (n=2) ( Fig. 62 ); interocellar distance 0.30 mm (0.27–0.33; n=2); ocellocular distance 0.55 mm (0.54–0.56; n=2); first flagellar article longer [0.61 mm (0.59–0.63; n=2)] than second and third flagellar articles combined [0.39 mm (0.38–0.39; n=2)]; length of malar area 0.15 mm (n=2). Mandible tridentate. Pronotal dorsolateral angle projected posterolaterally as a truncate lamella; intertegular distance 3.63 mm (3.56–3.70; n=2); mesoscutal length 2.80 mm (2.78–2.81; n=2); mesoscutellar length 1.33 mm (n=2); posterior margin of mesoscutellum evenly convex ( Fig. 60 ); mesotibial length 2.22 mm (n=2); mesobasitarsal length 2.19 mm (2.15–2.22; n=2), width 0.74 mm (n=2) (measured at proximal posterior keel), posterior keel projected in an acute angle, with proximal margin appearing straight (slightly convex) ( Fig. 66 ); metatibia triangular (scalene triangular) ( Fig. 64 ), maximum thickness 1.30 mm (1.26–1.33; n=2), length 3.56 mm (3.48–3.63; n=2), ventral margin length 2.28 mm (2.26–2.30; n=2), postero-dorsal margin length 4.48 mm (4.44–4.52; n=2); metatibial organ slit as described for E. viridis , dorsal section length 0.52 mm (n=2); metabasitarsal length 2.07 mm (n=2), mid-width 0.78 mm (n=2); metabasitarsal ventral margin truncate. Forewing length 8.78 mm (8.67–8.89; n=2); jugal comb with 14–15 (n=2) blades; hind wing with 22–26 (n=2) hamuli. Maximum metasomal width 4.63 mm (4.59–4.67; n=2); second metasomal sternum with two conspicuous cowled slits (sensu Roubik, 2004) converging mesially (no separation between them), together occupying about one third of sternum width, each cowl covering proximal section of setose tufts which in turn are also contiguous mesially ( Fig. 65 ).

Coloration. Head green (specimen deposited in London with blue coloration on vertex, frons, and clypeus), with golden-bronze highlights; lower width of paraocular ivory marks never wider than half length of lower lateral part of clypeus, remain- der of head structures colored as described for E. viridis ( Figs. 61–62 ). Mesosoma as described for E. viridis although mesoscutellum not as dark ( Figs. 60–61 ); legs as described for E. viridis , except they are mainly green with no blue-purple iridescence ( Figs. 61 , 63–64, 66 ). Metasomal terga as described for E. viridis , although seemingly metallic blue coloration on first to third terga rather cyan (specimen in London rather darker, with blue coloration extending to fourth and fifth terga) ( Figs. 60 ); sterna as described for E. viridis .

Sculpturing. Head as described for E. viridis ( Fig. 62 ). Central area of mesoscutum double punctate, regular-size punctures separated by two to three puncture diameters, minute punctures (easily differentiated from regular-sized punctures) interspaced and scarce, slightly increasing in density towards margins ( Fig. 60 ); mesoscutellum also double punctate, larger punctures double size of those on mesoscutum, separated from each other by one to one and a half puncture diameters, denser towards margins and leaving noticeably smooth area mesially ( Fig. 60 ); mesepisternum with punctures as large as those on mesoscutellum, central area with punctures separated by one puncture diameter, sparser (two puncture diameters between) on ventral areas, and denser (almost contiguous) towards upper sections ( Fig. 61 ). All metasomal terga (except central disc of first tergum and narrow posterior margin of first to fifth terga) with dense punctation, punctures about as large as those on mesoscutum ( Fig. 60 ); sterna as in E. viridis .

Vestiture. Head as described for E. viridis ( Fig. 62 ). Mesosoma as described for E. viridis , except posterior mesotibial tuft oblong and oriented diagonally ( Figs. 63 , 149 ). Metasoma as described for E. viridis ( Figs. 60–61 ), except as follows: contiguous tufts on second metasomal sternum coming off entire area covered by each integumental cowl (vide Structure, supra), and composed of a velvety carpet of fulvous, plumose, short, appressed setae under noticeably fulvous, simple, long setae, directed posteriorly ( Fig. 65 ).

Terminalia. Hidden sterna and genital capsule as described for E. viridis ( Fig. 159 ).

♀: Females of this species were included in the type series by Ducke (1902a); however, despite our efforts to borrow such material none were available for personal review, and so we do not offer a full description of the female at this time (vide Comments, infra). Females should share with males their coloration and, most importantly, the distinctive evenly convex posterior margin to the mesoscutellum.

LECTOTYPE: 1♂, Brazil: “ Brasil Pará 15.5.1902 Ducke [month, day, and last digit of year handwritten] // Euglossa polita LECTOALLOTYPUS Moure & Michener 1955 [handwritten with red ink] // Hymenoptera : Apocrita Aculeata : Apoidea : Apidae : Euglossinae : Euglossini : Euglossa polita Reorganizado 5.XII.1998 ” ( MPEG) (vide Comments on status as lectotype, infra).

ADDITIONAL MATERIAL EXAMINED (2♂♂): Brazil : 1♂, “ TYPE [round label with red margin] // B.M. TYPE; HYM.; 17B. 944. [last line handwritten] // Euglossa ; polita Ducke ; ♂ type [label handwritten] // Brazil.; Mus.Goeldi.; 1910-90 [some digits illegible] // Brasil.; Pará; 22.4. 19002 [1902]; Ducke” ( NHML). 1♂, “ BRAZIL: PARÁ; BELÉM, I.P.E.A.N.; 26 X/1968; R. L. Dressler; 1200 // Vanillin // Euglossa ; polita Ducke ; det. R. L. Dressler 1968” ( FSCA) .

COMMENTS: As was the case with E. azurea , this species was first published in German (Ducke, 1902a), with the intended initial description appearing subsequently in the same year and in a Brazilian journal (Ducke, 1902b). In the latter paper, Ducke (1902b) noted that the description was based on a series of no more than 17 specimens (5 females, 12 males), that we presume constitute the type series. In the German description that appeared prior (Ducke, 1902a), Ducke gives an abbreviated description of coloration and some sculpturing, but most notably he specifically refers to the distinctive cowled slits on the second metasomal sternum of the male and which are perhaps the most unique feature of this species among all other Euglossella . Moure (1967b) designated a lectotype, literally as “ Lectotype ♂: Coll. Ducke, Mus. Paraense, Belém”. Among the specimens here examined, one male belonging to the lectotype repository collection (Museu Paraense Emílio Goeldi, Belém, Pará, Brazil), bears a label “ Euglossa polita LECTOALLOTYPUS Moure & Michener 1955 [handwritten with red ink]”, while a female specimen deposited in the same collection, and unfortunately not available for personal examination, is labeled as the lectotype. Clearly this is another example of a discrepancy between the published lectotype designation (a male) and the labeling of specimens in the collection, as was the case for E. cyanea (vide Comments for that species, supra), and for others as well ( Nemésio & Rasmussen, 2011). As noted elsewhere, what takes nomenclatorial precedence is the published lectotype designation and not labeling within an institution, although it is always required that the lectotype be appropriately labeled and hoped that such a label is placed on the specimen that actually was alluded to in the official publication (which is not the case here). The ICZN (1999, Art: 74.5) dictates that in a validly published lectotype designation prior to 2000, “either the term ‘lectotype’, or an exact translation or equivalent expression (e.g. ‘the type’), must have been used or the author must have unambiguously selected a particular syntype to act as the unique name-bearing type of the taxon.” It is the published usage of this information that designates the lectotype, not merely adding labels to specimens in a collection (otherwise there would be no need to publish lectotype designations; but fortunately such actions are not permitted by the ICZN for the subsequent fixation of types). Unlike the case described for E. cyanea (vide supra) whereby the published notation regarding the sex of the type is demonstrably an error and could not be anything other (the Bolivian portion of the syntype series consisted of only a single male, with no such female specimen existing; nothing can be ambiguous about that!), here the collection holds both a male and female from Ducke’s syntype series meaning that there is a legitimate ambiguity. There are two possible courses of action that could be followed given the incertitude involved.

First, one could follow what is stated on the labels added by Moure and Michener during their examination of Ducke’s material in 1955 (whereby the lectotype would be a female, the allolectotype a male), implicitly granting the labeling ‘precedence’ owing that it was done in 1955 and more than a decade prior to the appearance of a published lectotype designation. This decision would be less ideal given that females exhibit few- er diagnostic features relative to males and particularly since the most important feature supporting the validity of the species is the presence of cowled slits on the male, a trait emphasized by Ducke (1902a, 1902b) himself. Nonetheless, one could make such an argument to consider the female as the ‘type’. In this scenario, one would have to argue that it is the labels that resolve the ambiguity and that the labels, independent of the publication by Moure (1967b), have some kind of precedence in fixing the type (after all, the ICZN says, “unambiguously selected a particular syntype ”), momentarily ignoring the fact that subsequent type designations must be validly published (which was not done by Moure and Michener in 1955 nor was done together by these authors at any time). However, within the context of Moure’s published designation there is no ambiguity as he unambiguously indicates the lectotype to be a male. The ambiguity is only introduced by the labeling found in Belém, a recourse that is not mentioned anywhere in the ICZN (1999) as taking precedence over the validly-published account. Thus, in order to truly follow this scenario to its extreme conclusion whereby the male is dismissed as the lectotype, one ultimately must declare Moure’s (1967b) published action as erroneous and invalid, presumably given his failure to unambiguously select a particular syntype (although, as already noted, it seems rather clear to us within the confines of his publication and not taking extraneous information into consideration), and elevate the female as lectotype (contra the published account and despite the fact that the available sexes of the syntypes mentioned does not conclusively exclude the possibility that the male was truly intended; the latter point of which was certainly not the situation for E. cyanea and why that case differs so significantly from the present one). We believe that this line of reasoning is the least defensible, particularly in that it means contradicting the ICZN (1999) and even perhaps dictating that unpublished accounts of labeling somehow are available to fix types. Moreover, if this scenario is taken to its most extreme conclusion, then the published designation would be deemed invalid (otherwise we see no legitimate, ICZN-backed reason to naturally follow the labeling to the exclusion of the publication and recognize the female), and whatever labels are on the specimens would become moot as there is then no published fixation of types, all specimens reverting to syntypes. A new lectotype designation would then be needed and the new author could select whichever sex he or she felt best (to which we would again argue that the male is to be preferred given that it is the cowled slits of this gender that are the most compelling argument for recognition of the biological entity).

The second option is to strictly follow the statement in the ICZN (1999: Art. 74.5, quoted above), and from the first, validly-published account consider the lectotype to be the specimen “unambiguously” referred to by the author. In this case, there is no mistaking what is printed and thereby intended in Moure (1967b) as in addition to mentioning the repository and his intention to designate a lectotype, he clearly states, “ ♂ ”, to which there is indeed in the repository noted such a male clearly from Ducke’s original series. Relying on the published information the identity of the lectotype does not appear to be all that ambiguous, and this is in accordance with the ICZN (1999). Under this scenario, the male must be considered the lectotype and the ‘Moure & Michener’ labels considered nothing more than a historical curiosity. Although lengthy and belabored, we believe that the explanations provided here are necessary to clarify and justify the conclusions we have reached regarding the status of the male designated by Moure (1967b), why we believe that it must be considered the lectotype un- der the ICZN (1999), and all of this despite the ambiguity generated by the erroneous labeling of specimens. Lastly, we believe our discussion here and our action to follow the designation of the male as the lectotype should serve as the final arbitrament of any dispute regarding its status as based on the principle of the ‘First Reviser’ (ICZN, 1999: Art. 24.2.1).

Although there was only a meager series available for study, there is observable variation in color among them, and the specimen deposited in London is noticeably darker than the others. The male mesotibial tufts in E. polita are more similar to those of E. viridis , whereby the anterior tuft is long and the contiguous velvety area is narrow; however, the posterior tuft in E. polita is distinctively oblong ( Figs. 63 , 149 ). Furthermore, males of E. polita are quite distinctive when compared to males of other species in the group, not only for the presence of the cowled-slits on the second metasomal sternum, but also for the particular shape of the posterior margin of the mesoscutellum, which is noticeably convex along its entire length ( Fig. 60 ) and lacks the medial flattening that is present in others (e.g., Fig. 58 ). Despite the rather conservative nature of female morphology across Euglossa , features such as the shape of the mesoscutellum are shared between sexes and it is presumed that in addition to sharing more superficial similarities such as coloration and vestiture, the female of the species should also have the distinctive mesoscutellar border in which the posterior margin is evenly convex rather than medially truncate. However, this must await confirmation when females of this rare species may be examined first hand.

Presently E. polita is known only from a few, less-than-specific localities in northwestern Brazil. The species has been collected in the state of Pará in northwestern Brazil ( Fig. 170 ), and has been reported by Moure et al. (2007) from the Brazilian state of Amazonas, although we never found specimens from that area.

Figures

Figure 170. Collection localities for species of Euglossella Moure, viridis and mandibularis species groups [also showing localities for females attributable only to Euglossa (Euglossella) viridis (Perty)/azurea Ducke]. Locality points are based on examined specimens.

Figures 60–61. Euglossa (Euglossella) polita Ducke, male. 60. Dorsal habitus. 61. Lateral habitus.

Figures 62–66. Euglossa (Euglossella) polita Ducke, male. 62. Facial aspect. 63. Mesotibial tufts. 64. Outer view of hind leg. 65. Posterior view of second metasomal sternum showing cowled slits. 66. Proximal section of mesobasitarsus.

Figures 144–154. Outer view of mesotibiae of males of species of Euglossella Moure, viridis and mandibularis species groups. 144. Euglossa (Euglossella) viridis (Perty). 145. E. (E.) azurea Ducke. 146. E. (E.) celiae, new species. 147. E. (E.) cyanea Friese. 148. E. (E.) subandina, new species. 149. E. (E.) polita Ducke. 150. E. (E.) perviridis Dressler. 151. E. (E.) cyanura Cockerell. 152. E. (E.) granti Cheesman. 153. E. (E.) mandibularis Friese. 154. E. (E.) bigibba Dressler.

Figures 155–163. Dorsal view of genital capsule of males of Euglossella Moure, viridis and mandibularis species groups. 155. Euglossa (Euglossella) azurea Ducke. 156. E. (E.) celiae, new species. 157. E. (E.) cyanea Friese. 158. E. (E.) subandina, new species. 159. E. (E.) polita Ducke. 160. E. (E.) perviridis Dressler. 161. E. (E.) cyanura Cockerell. 162. E. (E.) granti Cheesman. 163. E. (E.) bigibba Dressler.

Figures 53–59. Euglossa (Euglossella) subandina, new species, male holotype. 53. Facial aspect. 54. Mesotibial tufts. 55. Outer view of hind leg. 56. Proximal section of mesobasitarsus. 57. Lateral part of mesepisternum. 58. Mesoscutellum. 59. Dorsal view of metasomal terga.