Research Article |
Corresponding author: Mariano Lucia ( mlucia@fcnym.unlp.edu.ar ) Academic editor: Michael S. Engel
© 2015 Mariano Lucia, Victor H. Gonzalez, Alberto H. Abrahamovich.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Lucia M, Gonzalez VH, Abrahamovich AH (2015) Systematics and biology of Xylocopa subgenus Schonnherria (Hymenoptera, Apidae) in Argentina. ZooKeys 543: 129-167. https://doi.org/10.3897/zookeys.543.6300
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Biological information on the species of the large carpenter bee Xylocopa subgenus Schonnherria occurring in Argentina is revised. Based on the appraisal of museum specimens, the study of type material, and field surveys conducted across 15 provinces between 2007 and 2011, the following seven species are recognized for the country: X. bambusae Schrottky, X. chrysopoda Schrottky, X. macrops Lepeletier de Saint Fargeau, X. simillima Smith X. splendidula Lepeletier de Saint Fargeau, X. pulchra Smith, and X. viridis Smith. Previous literature records of X. dimidiata Latreille, X. subcyanea Pérez, and X. varians Smith for the province of Misiones appear to have been misidentified specimens, although the presence of these species in Argentina cannot be entirely ruled out given the proximity of this province to Brazil and Paraguay where they occur; X. boops Maidl was described from a male specimen with unusually enlarged eyes and is newly synonymized under X. macrops. Males and females of all species are diagnosed, described, and figured, including details of the male genitalia. Taxonomic comments, data on the geographical distribution and nesting substrates, and identification keys to all Argentinean species of Schonnherria are provided. The nesting biologies of X. splendidula and X. viridis are documented.
Anthophila , carpenter bees, host plants, nesting biology, pollinators, Xylocopini
Large carpenter bees of the genus Xylocopa Latreille (Apidae: Xylocopini) are conspicuous, commonly encountered, and fascinating elements of the melittofauna in many regions of the world. These usually robust, large, hairy bees nest in solid wood including structural timbers or in dead stalks of plants (hence their common name), althought some species nest in the ground. The more than 470 species are currently grouped in 31 subgenera, and approximately 100 species (in 12 subgenera) are recorded from the Neotropical region (
Carpenter bees are also economically important. Some species are effective pollinators of diverse crops, including passion fruit, squash, tomato, Brazilian nut tree, and eggplant, and they are already being used for this purpose in different countries (e.g.,
Despite the interesting biology, ecological importance and potential for development in crop pollination, most species of Xylocopa remain both biologically and taxonomically unknown. As for other taxa (
As part of an on-going effort to reduce such a taxonomic impediment and to increase our understanding of the biology of Neotropical carpenter bees, here we revise the species of Xylocopa subgenus Schonnherria Lepeletier de Saint Fargeau occurring in Argentina. This subgenus is the second most species-rich group of Xylocopa in the Western Hemisphere, containing about 30 species that range from southern United States to southern Argentina (
Morphological terminology generally follows that of
The primary types of all species treated herein were examined, as well as a total of 1702 specimens from all provinces of Argentina deposited in the following institutions and personal collections. The curators who kindly arranged the loans or allowed access to the collection in their care are indicated parentheses:
BMNH British Museum Natural History, London, UK (D. Notton)
CZ Private Collection of “Caire-Zelich”, Entre Ríos, Argentina (L. Caire-M. Zelich)
FAUBA
Facultad de Agronomía
IADIZA Instituto Argentino de Investigaciones de las Zonas Áridas, Mendoza, Argentina (G. Debandi)
IFML
Information on the distribution was taken from literature and from specimen labels. The biogeographic provinces referred in the distribution account for each species followed those of
Surveys for specimens as well as for nests of Xylocopa were conducted by M.L. between 2007 and 2011 across 15 provinces. The following provinces could not be sampled: Formosa, San Juan, La Pampa, Neuquén, Rio Negro, Santa Cruz, and Tierra del Fuego. When nests were found, the following variables were recorded: type of substrate and location (dead wood, structural timber, etc), plant species, and height above ground. Adults found inside nests were collected, killed, and deposited as vouchers in
Measurements of internal nest features were taken from the molds using a caliber. Mean values are provided with standard deviations. We used a Pearson correlation analysis to test for association between the following variables: tunnel length and tunnel width, total number of tunnels per nest and maximum diameter of the tree branch where the nest was found, total number of brood cells and total number of tunnels, and number of cells per number of tunnels and tunnel length.
Xylocopa (Schonnherria) Lepeletier de Saint Fargeau, 1841: 207. Type species: Xylocopa micans Lepeletier de Saint Fargeau, 1841, by designation of Sandhouse, 1943: 598.
Xylocopa (Schönherria) Dalla Torre, 1896, 202, lapsus calami pro Schonnherria Lepeletier de Saint Fargeau, 1841 (not Burmeister, 1855: 417 [Coleoptera: Scarabaeoidea]).
Shornherria Ashmead, 1899: 71, error for Schonnherria Lepeletier de Saint Fargeau, 1841.
Xylocopa (Schoenherria)
Xylocopa (Ioxylocopa)
Xylocopa (Xylocospila)
Species in the subgenus Schonnherria are small (15 mm) to moderately large bees (~24 mm), often with metallic highlights on all tagmata. Schonnherria can be distinguished from all other New World subgenera of Xylocopa by the following combination of characters: female mandible bidentate (except tridentate in X. viridigastra Lepeletier de Saint Fargeau, 1841), with apical tooth about as broad as or broader than basal tooth; T1 with complete gradulus on both sexes, remaining terga with gradulus absent (except in the male of X. bambusae with gradulus also on T2); male genitalia with a large spine of the ventral margin of the gonocoxite and the apex of the gonostylus bifid.
Xylocopa bambusae Schrottky, 1902: 475 (holotype:
Xylocopa eburnea Friese, 1903: 202 (lectotype:
Xylocopa bellula Brèthes, 1916: 413 (holotype:
Xylocopa (Xylocospila) bambusae:
The female of this species can be easily distinguished from other Argentinean species of Schonnherria by the following combination of characters: small body size (body length 14–17 mm); integument dark brown to black throughout, without metallic highlights; clypeus flat in profile, not elevated from adjacent paraocular area; clypeoalveollar distance long, about twice as long as longitudinal diameter of antennal socket; frontal carina projected into a distinct tubercle just above or at the upper tangent of anntenal sockets (Fig.
Body length 15.9 (14.0–17.3); head length 4.2 (3.9–4.4); head width 4.9 (4.6–5.0); mesosoma width 5.7 (5.2–6.0); metasoma width 6.5 (5.8–6.8); forewing length 13.2 (12.3–13.7); forewing width 3.8 (3.6–4.0). Coloration. Integument dark reddish brown to black throughout, without metallic highlights, light brown on anterior face of F2–F9 and impunctate distal margins of metasomal terga and sterna. Wings dark brown with coppery highlights basally, golden iridescent. Pubescence. Dark brown to black. Head with scattered setae on vertex, gena, and clypeus distally (Fig.
As in the female, except for usual secondary sexual characters and as follows: body length 15.9 (15.0–16.7); head length 3.5 (3.5–3.6); head width 4.4 (4.4–4.6); mesosoma width 6.3 (6.0–6.6); metasoma width 6.6 (6.0–7.0); forewing length 11.6 (11.0–12.7); forewing width 3.6 (3.4–3.8). Coloration. Cream to yellowish maculations as follows: labrum, mandible basally, clypeus, supraclypeal area, paraocular area (except on upper one-third), anterior surface of flagellum (Fig.
Genital capsule of males of Xylocopa subgenus Schonnherria from Argentina. All figures in dorsal view except Fig. 30 in ventral view. 25, 30 X. bambusae 26 X. chrysopoda 27 X. macrops 28 X. splendidula 29 X. viridis. Abbreviations: lc = lateral carina of penis valve; vp: ventroapical plate of gonocoxite.
This species is also known from Brazil and Paraguay (Table
Summary of species of Xylocopa subgenus Schonnherria occuring in Argentina with information on their distribution. Province: BA = Buenos Aires; CA = Catamarca; CH = Chaco; CO = Córdoba; CT = Corrientes; ER = Entre Rios; FO = Formosa; JU = Juyuy; LP = La Pampa; LR = La Rioja; MZ = Mendoza; MI = Misiones; NQ = Neuquén; RN = Río Negro; SJ = San Juan; SL = San Luis; ST = Salta; SG = Santiago del Estero; SF = Santa Fe; TU = Tucumán. ? = province listed in the literature, but not confirmed in this study. General distributions were extracted from
Species | General distribution | Distribution in Argentina | Altitude (m.a.s.l) in Argentina |
---|---|---|---|
X. bambusae Schrottky | Argentina, Brazil, Paraguay | MI | 50–200 |
X. chrysopoda Schrottky | Argentina, Brazil | MI | 170 |
X. macrops Lepeletier de Saint Fargeau | Argentina, Bolivia, Brazil, Colombia, Paraguay, Peru | BA, CH, CT, ER, FO, JU?, MI, SF, SG?, TU | 0–1100 |
X. pulchra Smith | Argentina, Brazil, Colombia, Paraguay | MI, ST | 170 |
X. simillima Smith | Argentina, Bolivia, Brazil, Paraguay, Peru | MI | 170 |
X. splendidula Lepeletier de Saint Fargeau | Argentina, Brazil, Chile, Paraguay, Peru, Uruguay | BA, CA, CH, CH, CO, CT, ER, FO, JU, LP, LR, MZ, MI, NQ, RN, ST, SJ, SL, SF, SG, ST, TU | 0–2700 |
X. viridis Smith | Argentina, Bolivia, Brazil, Colombia, Costa Rica, French Guiana, Guatemala, Guyana, Mexico, Panama, Paraguay, Peru | MI | 170 |
Despite actively searching for nests as well as specimens of this species in insect collections and in the field, the only specimens available to us were those collected by Peter Jörgensen at different times of the year in Misiones during the first decade of 1900 (see supplemental material). The species has not been collected ever since. The nesting biology of this X. bambusae is unknown, although it presumably nests in bamboo stalks (
Xylocopa chrysopoda Schrottky, 1901: 214 (nomen nudum)
Xylocopa chrysopoda Schrottky, 1902: 475 (holotype:
Xylocopa (Ioxylocopa) chrysopoda:
This species is known only from the male. It can be distinguished from other Argentinean species of Schonnherria by the following combination of characters: small body size (body length 17.0–17.7); integument dark brown to black throughout, at most with faint metallic highliths on metasomal terga; compound eyes not enlarged, parallel or nearly so (Fig.
Body length 17.3 (17.0–17.7); head length 3.5 (3.5–3.6); head width 4.4; mesosoma width 6.0; metasoma width 6.7 (6.6–6.8); forewing length 14; forewing width 3.5 (3.4–3.6). Coloration. Integument dark brown to black except tarsi light reddish brown and cream to yellow maculations as follows: outer surface of mandible (except margins), clypeus, supraclypeal area basally, and paraocular area (except on upper one-third) (Fig.
Unknown.
This species is known only from Brazil and the province of Misiones in Argentina, the latter area included in the Paranaense biogeographic province (Fig.
Schrottky (1912) suggested that X. chrysopoda may be the male of X. pulchra, a species currently known from the female sex. As for X. bambusae, these two species are rarely collected and are currently known from a limited number of specimens. We did not collect nor examine specimens of X. chrysopoda from Argentina captured in the last 100 years.
Xylocopa macrops Lepeletier de Saint Fargeau, 1841: 209 (holotype: ♂, Brazil, whereabouts unknown)
Xylocopa crotalariae Schrottky, 1901: 212, 214 (nomen nudum)
Xylocopa crotalariae Schrottky, 1902: 472 (holotype:
Xylocopa boops Maidl, 1912: 325 (holotype:
Xylocopa (Schonnherria) macrops:
The female of this species can be distinguished from other Argentinean species of Schonnherria by the following combination of characters: medium-sized bees (18–22 mm); body pubescence black; integument black throughout with very weak metallic blue, often most evident on mesoscutum, tegula, outer surfaces of pro- and mesotibiae, and metasomal terga; clypeus depressed basally on disc, dorsolaterally elevated from adjacent paraocular area (Fig.
Body length 19.6 (18.3–21.7); head length 5.1 (4.8–5.4); head width 6.1 (5.8–6.4); mesosoma width 6.6 (6.2–7.0); metasoma width 7.6 (7.2–8.0); forewing length 15.9 (15.0–17.3); forewing width 4.8 (4.4–5.4). Coloration. Integument dark reddish brown to black with weak metallic blue-green highlights, particularly on mesoscutum and metasomal terga. Wing dark brown to black with metallic violet-green highlights. Pubescence. Predominantly black, except by pale setae intermixed with black setae on face and sides of T4–T6 and S4–S6 (sometimes absent). Head with abundant setae, scattered on gena. Mesosoma with abundant, plumose setae, nearly asetose on discs of mesoscutum and mesoscutellum. T1 with plumose setae on basal half, with very short simple setae on distal half, each seta barely exiting puncture; T2–T5 with short setae as on distal half of T1, setae longer and denser on sides of T5 and T6 (Fig.
As in the female, except for usual secondary sexual characters and as follows: body length 21.6 (20.7–22.7); head length 5.1 (4.9–5.4); head width 6.2 (6.0–6.4); mesosoma width 7.3 (7.0–7.6); metasoma width 7.7 (7.2–8.0); forewing length 15.5 (14.3–16.0); forewing width 4.1 (4.0–4.4). Coloration. Integument with distinct metallic blue-green highlights. Cream to yellow maculations as follows: labrum, mandible basally (sometimes absent), clypeus, supraclypeal area, inferior paraocular area, anterior surface of scape, and discs of S2–S6 each with sublateral, triangular maculation (sometimes absent on S2, S5 and S6). Wings hyaline to subhyaline with weak golden highlights. Pubescense. Longer and denser than on female, predominantly whitish, except dark brown to black on: interocelar area, vertex, pronotal lobe, metepisternum, propodeum, procoxa, inner surfaces of profemur and protarsi, remaining legs excluding posterior margin of metatibia, sides of T1, T5, T6, sides of sterna, and discs of S4–S6. White pubescence on T1 dense, nearly obscuring integument. Sculpturing. Coarser and denser than in female, particularly on sides of mesoscutum and mesoscutellum, and terga (Fig.
This species appears to be widely distributed in South America, occuring from Colombia to Brazil (Table
Xylocopa pulchra Smith, 1854: 361 (holotype: BMNH 17B.188; ♀, Rio, Brazil) (examined)
Xylocopa (Schonnherria) pulchra:
This species is known only from the female. It can be easily recognized by the following combination of characters: small body size (body length 15–17 mm); upper gena and vertex densely punctate, punctures separated by at most a puncture width; wings subhyaline, yellowish; metasoma dark brown to black with weak blue-green metallic highlights; and discs of T2–T5, each with a broad, medially interrupted apical band of dense yellowish setae (Fig.
Body length 16 (15.3–16.7); head length 4.1 (4.0–4.2); head width 5.1 (5.0–5.2); mesosoma width 5.7 (5.6–5.8); metasoma width 6.1 (6.0–6.2); forewing length 11.3 (10.7–12.0); forewing width 3.2. Coloration. Integument dark brown to black including tegula, with weak blue-green higlights on metasoma. Wings subhyaline with weak golden highlights, veins yellowish-brown. Pubescence. Dark brown to black, except: anterior surface of metatibia distally, outer surface of metabasitarsus, and sides of S2–S4 with whitish setae; metabasitarsus externally with pale hairs; discs of T2–T5 each with a broad, medially interrupted apical band of dense yellowish setae (Fig.
Unknown
Xylocopa pulchra is known only from the female, and the male of X. chrysopoda may be conspecific with this species, as suggested by
Xylocopa simillima Smith, 1854: 357 (holotype: BMNH 17B.196; ♀, Australia) (examined)
Xylocopa mendax Maidl, 1912: 319 (syntype:
Xylocopa rotundiscuta Brèthes, 1916: 418 (lectotype:
Xylocopa (Schonnherria) simillima:
The female of this species can be distinguished from other Argentinean species of Schonnherria by the following combination of characters: large body size (body length 20–23 mm); labrum basally with a distinct, large, single capitate tubercle about as large as median ocellus; integument dark brown to black throughout, with basal three or four terga often with distinct broad, light reddish brown bands on discs (rarely orange) (Fig.
Body length 21.8 (20.3–23.0); head length 5.8 (5.5–6.1); head width 6.6 (6.4–7.0); mesosoma width 7.5 (7.2–8.4); metasoma width 9.1 (8.8–9.6); forewing length 19.6 (18.6–19.7); forewing width 5.7 (5.6–6.2). Coloration. Integument black with posterior margin of mesoscutellum and basal three or four metasomal terga with broad, light reddish brown bands on discs (terga rarely orange). Wings dark brown with violet highlights. Pubescence. Dark brown to black. Head with scattered setae on vertex, gena, paraocular area, and clypeus distally. Mesosoma with abundant, plumose setae except nearly asetose on disc of mesoscutum and posterior half of mesoscutellum. T1 with scattered plumose setae on basal half; distal half of T1, as on discs of T2–T5, with very short (0.2–0.3 times OD), appressed simple setae, each barely exiting puncture, setae becoming longer and denser towards apical terga; disc of T6 and sides of T1–T6 each with long, semierect, simple and plumose setae; sterna with semierect, long setae as long as those on sides of terga. Sculpturing. Weakly imbricate to smooth and shiny. Vertex and upper gena largely impunctate, punctures denser behind lateral ocelli. Mesoscutum with punctures slightly smaller and denser than those on vertex on anterior margin and lateral to parapsidal lines, impunctate otherwise; mesoscutellum largely impunctate, punctures separated by at least two times a puncture width. Terga with circular to ovoid punctures as large and coarse as those on mesoscutellum, separated by 1–2 times a puncture width, denser laterally on each tergum and towards apical segments; sterna with punctures smaller, nearly contiguous laterally, larger and sparser medially. Structure. Head broader than long (1.1–1.2:1); compound eyes with inner margins parallel; proportion of upper to lower interocular distance 0.8–0.9:1; middle interocular distance 4.2–4.5; vertex broad, distance between median ocellus and posterior margin of vertex 4.6–5.3 OD; orbitoccipital distance short 1.1–1.3; lateral ocelli below supraorbital line; interocellar distance to ocelocular distance 0.6:1; interocellar to ocelloccipital 0.3–0.4:1; ocellocular to alveolocellar 0.7–0.9:1; orbitoccipital to ocellocular 1.0–1.3:1; alveolocular to interalveolar 1.2–1.4:1; clypeoalveolar distance about 1.8 times longitudinal diameter of antennal socket; clypeocellar distance to distance between median ocellus and posterior margin of vertex 0.7–0.9:1; frontal carina moderately elevated, forming a small tubercle just above lower tangent of anntenal sockets; clypeus broader than long, 2.2–2.5:1; proportion of length of scape, pedicel and F1–F4: 2.9–3.2:0.2–0.4: 1:0.3–0.4:0.4–0.5:0.4–0.5, respectively; labrum basally with a distinct, large, single capitate tubercle about as large as median ocellus. Mesoscutellum gently convex; metanotum and propodeum vertical in profile.
As in the female, except for usual secondary sexual characters and as follows: body length 22.6; head length 5.7; head width 6.8; mesosoma width 8.8; metasoma width 9.8; forewing length 20.6; forewing width 5.6. Coloration. Clypeus, supraclypeal area and lower paraocular area yellow. Structure. Head broader than long (proportion 1.2:1); compound eyes enlarged, strongly converging dorsally (Fig.
This species occurs in Misiones (Fig.
Brèthes’ original description of X. rotundiscuta was based on three females. To stabilize this name,
Xylocopa splendidula Lepeletier de Saint Fargeau, 1841: 190 (holotype: ♀, Brazil, whereabouts unknown, see comments below)
Xylocopa (Schonnherria) splendidula:
Both sexes of this species can be distinguished easily from other Argentinean species of Schonnherria by the following combination of characters: small to medium body size (body length 13–19 mm); body pubescence entirely black in the female, in the male with dense off-white pubescence on mesepisternum, tegula anteriorly, sides of mesoscutum and mesoscutellum, and dorsum of T1; meso- and metasoma with distinct metallic blue highlights; wing membrane subhyaline with weak violet highlights; male compound eyes enlarged, dorsally convergent, with upper margins separated by at least 2.7 times OD (Fig.
Body length 17.2 (16.6–18.3); head length 4.9 (4.7–5.0); head width 5.5 (5.2–5.8); mesosoma width 6.3 (5.8–6.6); metasoma width 7.1 (6.6–7.5); forewing length 13.3 (12.7–14.0); forewing width 3.7 (3.6–3.8). Coloration. Integument dark brown to black with distinct metallic blue highlights, particularly dorsum of meso- and metasoma. Wings subhyaline with weak violet highlights. Pubescence. Dark brown to black, except patch of off-white setae on sides of T5. Head with abundant setae, scattered on gena and vertex. Mesosoma with abundant, plumose setae except nearly asetose on disc of mesoscutum and anterior half of mesoscutellum. T1 with scattered plumose setae on basal half; distal half of T1, as on discs of T2–T5, with very short, appressed simple setae, each barely exiting puncture, setae becoming longer and denser towards apical terga; disc of T6 and sides of T1–T6 each with long, semierect, simple and plumose setae; sterna with semierect, long setae as long as those on sides of terga. Sculpturing. Weakly imbricate to smooth and shiny. Vertex and upper gena with punctures separated by 1–2 times a puncture width, punctures scattered on upper gena. Mesoscutum with punctures separated by 1–2 times a puncture width, punctures becoming sparser towards center to completely absent on disc; mesoscutellum largely impunctate, with few, scattered punctures. Metasomal terga with circular to ovoid punctures separated by 1.0–1.5 times a puncture width, punctures becoming denser laterally and towards apical terga; sterna with elongate punctures on discs, punctures contiguous laterally, becoming sparser medially. Structure. Head broader than long (1.1–1.2:1); compound eyes with inner margins parallel; proportion of upper to lower interocular distance 0.8–0.9:1; middle interocular distance 3.4–4.0; vertex broad, distance between median ocellus and posterior margin of vertex 3.7–4.4 OD; orbitoccipital distance 0.6–0.8; lateral ocelli below supraorbital line; interocellar distance to ocelocular distance 0.9–1:1; interocellar to ocelloccipital 0.5–0.6:1; ocellocular to alveolocellar 0.6–0.8:1; orbitoccipital to ocellocular 0.9–1.1:1; alveolocular to interalveolar 1.0–1.3:1; clypeoalveolar distance 1.3 times longitudinal diameter of anntenal socket; clypeocellar distance to distance between median ocellus and posterior margin of vertex 0.8–1:1; frontal carina moderately elevated, forming a small protuberance at level of lower tangent of anntenal sockets; clypeus broader than long, 2.1–2.3:1; proportion of length of scape, pedicel and F1–F4: 3.2–3.5:0.3–0.5:1:0.3–0.4:0.4–0.5:0.4–0.5, respectively; labrum broader than long, with three basal protuberances, median tubercle distinct, longitudinally elongate, sublateral tubercles small. Mesoscutellum gently convex; metanotum and propodeum subvertically inclined.
As in the female, except for usual secondary sexual characters and as follows: body length 16.1 (13.3–18.6); head length 4.7 (3.8–4.4); head width 4.9 (4.6–5.2); mesosoma width 6.2 (5.6–6.8); metasoma width 6.8 (6.6–7.6); forewing length 12.6 (12.0–13.3); forewing width 3.3 (3.2–3.4). Coloration. Clypeus, supraclypeal area, paraocular area, and anterior surfaces of scape and F1 yellow (Fig.
This species is presumably widespread in South America (Table
In specimens of both sexes the color of legs, propodeum, mandibles and tegulae ranged from black to dark brown, and that of the metasoma from greenish to bluish. The presence of tufts of white setae on the sides of the terminal terga is also a variable character.
Xylocopa viridis Smith, 1854: 360 (holotype: BMNH 17B.186; ♂, Rio Tapajós, Pará, Brazil) (examined)
Xylocopa (Schonnherria) viridis:
Both sexes of this species are easily recognized by the distinctive metallic green highlights on all tagmata, body pubescence yellowish, and metasomal terga uniformly covered by long, appressed simple setae on discs, and with white, tomentose, plumose setae on apical margins laterally (Figs
Body length 16.7 (14–18); head length 4.5 (4.3–4.7); head width 5.1 (4.6–5.4); mesosoma width 5.9 (5.4–6.2); metasoma width 6.5 (6.0–6.8); forewing length 11.7 (11.0–12.3); forewing width 3.1 (3.0–3.2). Coloration. Integument dark brown to black with strong metallic green highlights. Wing subhyaline with weak golden highlights. Pubescence. Predominantly whitish to yellowish; black or gray setae on face, vertex, upper gena, mesoscutum, mesoscutellum, sides of T2–T5, and most of T6, S5 and S6; ferrugineous setae on inner surface of tarsi. Head and mesosoma with abundant setae, except asetose on discs of mesoscutum and mesoscutellum. Basal half of T1 with scattered, semierect simple setae; distal half of T1 and T2–T6 with appressed setae on discs, each setae at least twice as long as a puncture width, becoming longer towards apical terga, apical margins laterally with dense, white tomentum of appressed plumose setae (Fig.
As in the female, except for usual secondary sexual characters and as follows: Body length 15.3 (14.3–16.3); head length 3.7 (3.5–3.8); head width 4.3 (4.0–4.4); mesosoma width 5.6 (5.2–6.0); metasoma width 6.1 (5.6–6.6); forewing length 12.1 (11.3–12.7); forewing width 3.2 (3.0–3.4). Coloration. Outer surface of mandible, labrum, clypeus, supraclypeal area, and anterior surfaces of scape, F1 and F2 yellow. Tegula reddish brown. Pubescence. Longer and denser than in female. Structure. Compound eyes with inner margins slightly converging dorsally; proportion of upper to lower interocular distance 0.8:1; upper interocular distance 4.0–4.6 OD; middle interocular distance 1.9–2.0; distance between median ocellus and posterior margin of vertex 2.4–2.7 OD; orbitoccipital distance 0.2–0.3; interocellar distance to ocelocular distance 1.8–2.2:1; interocellar to ocelloccipital 0.7–1:1; ocellocular to alveolocellar 0.2–0.3:1; orbitoccipital to ocellocular 0.8–1:1; alveolocular to interalveolar 0.6–0.7:1; clypeocellar distance to distance between median ocellus and posterior margin of head 1.2–1.3:1; clypeus broader than long, 1.4–1.6:1; proportion of length of scape, pedicel and F1–F4: 2.8–3:0.4–0.6:1:0.4–0.5:0.5–0.6:0.5–0.6, respectively. Legs slender, unmodified, except metatibia with blunt subapical projection on inner margin, shorter and thicker than tibial spur; mesobasitarsi longer than tibiae. Genitalia as in Figs
This species has been recorded from Bolivia, Brazil, Colombia, Costa Rica, French Guiana, Guatemala, Guyana, Mexico, Panama, Paraguay and Peru (
Xylocopa viridis, ranging from southern Mexico to Argentina, appears to be composed of multiple species. An appraisal of museum specimens under X. viridis deposited at
Specimens of X. viridis from Argentina and southern Brazil also seem to be different from those of northen Brazil, particularly in the length of the setae on metasomal terga, the color of tegulae, and the shape of the apical projection on the inner surface of male metatibia. Such differences are suggestive of a distinct species and further studies are needed to determine the species limits of X. viridis.
Four nests of X. splendidula and 10 nests of X. viridis were found in total. Nests of X. splendidula were found in Villa Atamisqui (28°27’ 36”S, 63° 50'53”W, 123 m.a.s.l) in Santiago del Estero and the following three localities in the province of Buenos Aires: Berisso (34°53'12"S, 57°53'41"W, 6 m.a.s.l), Gral. Dorrego (38°52'37”S, 61°27'41"W, 32 m.a.s.l), and Mercedes (34°38'57"S, 59°24'50"W, 39 m.a.s.l). These nests were found inside dead branches of the following plant species: Syagrus romanzoffiana (Cham.) Glassman (Arecaceae), Stetsonia coryne (Salm-Dyck) Britton & Rose (Cactaceae), Salix sp. (Salicaceae), and Parkinsonia aculeata L. (Fabaceae). Sometimes nests of Xylocopa (Neoxylocopa) augusti Lepeletier de Saint Fargeau as well as X. frontalis were found in the same branch with nests of this species.
Nests of X. viridis were collected in two localities in the province of Misiones: Loreto (27°20'16"S, 55°31'55"W, 175 m.a.s.l.) and Iguazú (25°40'41"S, 54°26'58"W, 191 m.a.s.l). All nests were found inside dead branches of Hovenia dulcis Thunb. (Rhamnaceae). As in X. splendidula, nests of X. frontalis were also found in the same branch with nests of X. viridis.
As in other species of Xylocopa (e.g.,
Measurements (mm) of the nests of X. splendidula and X. viridis from Argentina. Means are given with standard deviation followed by the range and sample size in parenthesis.
Nest feature | Xylocopa splendidula | Xylocopa viridis |
---|---|---|
Branch diameter | 83.8 ± 40.8 (53.0–142.0, n = 4) | 113.0 ± 15.6 (95.0–128.0, n = 10) |
Nest entrance diameter | 7.0 ± 0.76 (6.0–8.0, n = 8) | 7.5 ± 0.76 (7.0–9.0, n = 20) |
Vestibule | 16.2 ± 6.3 (12.0–20.0, n = 5) | 22.4 ± 2.8 (13.0–26.0, n = 9) |
No. Tunnels | 8.8 ± 10.2 (3.0–24.0, n = 4) | 5.3 ± 4.6 (1.0–14.0, n = 10) |
Tunnel diameter | 8.8 ± 1.0 (6.9–11.2, n = 35) | 9.8 ± 0.9 (7.9–12.0, n = 53) |
Tunnel length | 51.7 ± 26.0 (12.0–113.0, n = 35) | 56.5 ± 24.8 (18.0–153.0, n = 35) |
Number of cells per nest | 18.5 ± 23.8 (4.0–54.0, n = 4) | 12.6 ± 13.8 (0.0–36.0, n = 10) |
Cell partition | 3.5 ± 0.8 (3.0–5.0, n = 15) | 4.6 ± 1.1 (2.5–6.0, n = 23) |
Cell length | 12.1 ± 1.4 (10.0–15.0, n = 75) | 11.4 ± 1.8.8 (9.0–19.0, n = 127) |
The number of adult females present at the time of collection ranged from one to six in nests of X. viridis (x= 2.3 ± 1.8) and from one to four in nests of X. splendidula (x = 2.7 ± 1.2); adult males were found only in three nests of X. viridis (x = 2.0, 1–3, ± 1.0) and in one nest of X. splendidula (7 males). Females were not dissected to examine the ovarian development or the presence of sperm in their spermatheca. Three females and one male of X. viridis were found dead inside the nest and were parasitized by the conopid fly Physocephala sp.; likewise, P. wulpi Camras was found parasitizing adults of X. splendidula (
The presence of seven of the 11 species of Xylocopa (Schonnherria) recorded for Argentina by
Only two of the seven species of Xylocopa (Schonnherria) occurring in Argentina are widely distributed in the country. Xylocopa splendidula exhibits the widest range, found everywhere except in Tierra del Fuego and Santa Cruz (Fig.
In this study we were able to recognize a number of structural characters in both sexes that seem reliable in species recognition, such as size, shape, density, and distribution of punctures, length, density and type of setae, male sexual secondary modifications (projections of legs, particularly on inner surface of metatibia), and features of the male genitalia. Althought some of these characters have been mentioned by some authors, to date, an emphasis has been made to use patterns of coloration of wings and pubescence (e.g.,
The nesting biologies documented here for X. splendidula and X. viridis agree with those of other species of the genus that nest in solid wood, including species of Schonnherria (e.g.,
The province of Misiones contains the highest diversity of large carpenter bees in Argentina (
Females
Note. The female of X. chrysopoda is unknown.
1 | Labrum basally with a distinct, large, single capitate tubercle about as large as the median ocellus (Fig. |
X. simillima Smith |
– | Labrum basally with a longitudinally elongated median tubercle and two small sublateral tubercles (often obscured by dense setae); color of metasomal terga variable, never orange or with light reddish brown bands; color of wings variable, hyaline to black; small to medium-sized bees (body length 14–22 mm) | 2 |
2(1) | Discs of T2–T5, each with a broad, medially interrupted apical band of dense yellowish setae (Fig. |
X. pulchra Smith |
– | Discs of T2–T5 without broad, medially interrupted apical bands of dense yellowish setae | 3 |
3(2) | Mesoscutellum posteriorly and metasomal terga with distinct metallic green or blue highlights; wings hyaline or subhyline with light reddish brown veins | 4 |
– | Mesoscutellum posteriorly and metasomal terga dark brown to black without metallic highlights, at most with very weak blue reflections; wing membrane and venation dark brown to black | 5 |
4(3) | Metasomal terga with metallic green highlights, densely and uniformly punctate except along midline, setiferous punctures elongate, separated by a puncture width or less; T1–T5 with yellowish setae on discs, apical margins laterally with dense, white tomentum of appressed plumose setae (Fig. |
X. viridis Smith |
– | Metasomal terga with metallic blue highlights, sparsely punctate, setiferous punctures circular or slightly ovoid, separated by 1–3 times a puncture width; discs of T1–T5 with dark brown to black setae, apical margins without tomentum (Fig. |
X. splendidula Lepeletier de Saint Fargeau |
5(3) | Clypeus flat in profile, dorsolaterally not elevated from adjacent paraocular area; supraclypeal area flat, frontal carina projected into a distinct tubercle just above or at the upper tangent of anntenal sockets (Fig. |
X. bambusae Schrottky |
– | Clypeus depressed basally on disc, dorsolaterally elevated from adjacent paraocular area; supraclypeal area depressed on disc, laterally elevated from adjacent paraocular area, frontal carina elevated and forming a low tubercle near lower tangent of antennal sockets, continuing dorsally into a low carina (Fig. |
X. macrops Lepeletier de Saint Fargeau |
Males
Note. The male of X. pulchra is unknown.
1 | Compound eyes strongly convergent dorsally, upper interocular distance less than three times OD (Fig. |
2 |
– | Compound eyes not distinctly convergent dorsally, inner margins parallel or nearly so, upper interocular distance at least four times OD (Fig. |
4 |
2(1) | Upper interocular distance 0.4 to 0.6 times lower interocular distance; small bees (body length 13–19 mm) | X. splendidula Lepeletier de Saint Fargeau |
– | Upper interocular distance 0.1 to 0.3 times lower interocular distance; larger bees (body length 21–23 mm) | 3 |
3(2) | Labrum black (Fig. |
X. simillima Smith |
– | Labrum yellow (Fig. |
X. macrops Lepeletier de Saint Fargeau |
4(1) | Supraclypeal area with a distinct tuft of long, erect, dense setae obscuring integument (Fig. |
X. bambusae Schrottky |
– | Supraclypeal area without a tuft of long, erect, dense setae; protrochanter without spine or tubercle; ventral surface of metatrochanter and metafemur basally pubescent, not distinctly protuberant; T1–T5 inmaculate | 5 |
5(4) | Metasomal terga with distinct metallic green highlights, densely and uniformly punctate, setiferous punctures elongate, separated by a puncture width or less; T1–T5 with short (≤ 1.0 OD) setae on discs, apical margins laterally with dense, white tomentum of appressed plumose setae (Fig. |
X. viridis Smith |
– | Metasomal terga dark reddish brown to black, at most with weak metallic highlights, setiferous punctures circular to ovoid, separated by 1–2 times a puncture width; T1–T5 with distinctly long (≥ 2.0 OD) setae on discs, apical margins without tomentum (Fig. |
X. chrysopoda Schrottky |
We are indebted to each of the curators, collection managers, and staff from the collections we visited or from which we borrowed material for this study (listed in the material and methods). We thank Leopoldo Alvarez and Bárbara Defea for their support and assistance during the field surveys, and Amy Comfort de Gonzalez, Eduardo Almeida and Jakub Straka for their comments and suggestions that improved this work. Bárbara Defea and Amy Comfort de Gonzalez also lovingly provided (to M.L. and V.H.G.) constant support and encouragement throughout of this work. Financial support to M.L and A.H.A was provided by the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina (CONICET).