Archive for the ‘Taxonomy’ Category

Subspecies in Osmia (Helicosmia)

Sunday, June 19th, 2022

In the following three European species of the subgenus Osmia (Helicosmia), populations were given subspecific rank solely due to the white rather than yellowish pilosity of head, mesosoma and terga in the female sex:

– Osmia signata rhodia Tkalců, 2005 on Rhodes;

– Osmia labialis tornensis Tkalců, 1995 in eastern Europe;

– Osmia latreillei iberoafricana Peters, 1975 on the Iberian peninsula, Balearic Islands, Corsica, Sardinia, Sicily, Malta and Cyprus.

As the different colour of the body pilosity is not known to be accompanied by other morphological differences compared to the nominate subspecies and as transitional populations occur containing both white and yellow haired individuals (e.g. in O. latreillei on Corsica, Sardinia and the Canary Islands; Tkalců, 1975a; Zanden, 1983; Warncke, 1988a), the subspecific rank of these three taxa does not seem to be justified. Thus, the three subspecies are synonymized with Osmia signata Erichson, 1835, Osmia labialis Pérez, 1879 and Osmia latreillei (Spinola, 1806), respectively.

Osmia dimidiata assomatosana

Saturday, June 18th, 2022

Le Goff (2005) described a new subspecies of Osmia dimidiata Morawitz, 1870 based on specimens from Crete, i.d. O. d. assomatosana. According to the author, this subspecies is mainly characterized by the whitish rather than yellowish colour of the light hairs of the two-coloured metasomal scopa. The investigation of a large material of O. dimidiata from Mediterranean Europe and western Asia revealed that females with a white-black rather than yellow-black scopa are not restricted to Crete but also occur e.g. in Italy, Turkey or Israel. Thus, the subspecific rank of the Cretean population of O. dimidiata does not seem to be justified and consequently, O. d. assomatosana is synonymized here with O. dimidiata

Osmia aurulenta and O. tunensis

Saturday, June 18th, 2022

Tkalců (1970) treated the two closely related and morphologically very similar taxa Osmia tunensis (Fabricius, 1787) and Osmia aurulenta (Panzer, 1799) as different species. The original description of the two taxa was based on specimens from the Maghreb for O. tunensis and from central Europe for O. aurulenta. In contrast, Warncke (1988a) considered O. aurulenta to be a subspecies of O. tunensis, which was again rejected by Schwarz et al. (1996), who supported the view of Tkalců (1970).

North African specimens of O. tunensis differ from central and east European specimens of O. aurulenta by i) a slightly shorter vertex, ii) a slightly denser punctation of the scutum, iii) a longer pilosity on both discs and marginal zones of the terga, iv) a brightly foxy red rather than yellowish-red pilosity of scutum, scutellum, mesepisternum and terga, which is of about the same colour as the metasomal scopa in the female, and v) a yellowish(-red) rather than whitish pilosity of face, underside of mesosoma and tergum 1 in the male. Specimens from Sicily and Malta have characters iii)-v) in common with north African specimens, whereas they have a similarly long vertex and a similarly dense punctation of the scutum as central European specimens. Specimens from southwestern and southeastern Europe correspond to central and east European specimens in all five characters.

Characters i) and ii) appear to be taxonomically superior compared to characters iii) – v) as the length and colour of the body pilosity is expected to more strongly vary depending on altitude, geographic latitude or climatic conditions. In fact, the body pilosity of many aculeate hymenopteran species is well known to become more reddish towards the south. Thus, pending future genetic studies, O. tunensis and O. aurulenta are tentatively treated here as different species with the former restricted to northern Africa and the latter occurring in Europe and western Asia. Specimens from Sicily and Malta are considered to belong to O. aurulenta as the differences with mainland European specimens only concern the length and colour of the body pilosity.

Osmia mirhiji is a member of O. (Tergosmia)

Friday, May 6th, 2022

The systematic position of Osmia mirhiji Mavromoustakis, 1957 was unclear. Due to the weak metallic blue to green sheen of head and terga of the female, Mavromoustakis (1957) assigned the species to the subgenus Chalcosmia = Helicosmia. However, the structure of the clypeus deviates from that of Osmia (Helicosmia) but is instead similar to that of Osmia (Tergosmia) or Hoplitis (Anthocopa). The recent examination of several males revealed that Osmia mirhiji actually belongs to the genus Osmia (punctiform parapsidal lines, lack of lateral tooth at tergum 6, lack of basal flaps at base of sternum 6) and that it shows the typical male characters of Osmia (Tergosmia), such as the similar form and size of sterna 2-3 lacking fringed emarginations, the strong and haired median emargination of sternum 5 and the shape of tergum 7. Thus, Osmia mirhiji is newly placed into the subgenus Osmia (Tergosmia). It is the only species of this subgenus with a metallic body sheen.

Osmia cinctella regarded as nomen dubium

Monday, May 2nd, 2022

Osmia cinctella was described by Dours (1873) based on specimens both from Greek islands (probably Crete) and Algeria. Based on the original description, Osmia cinctella belongs to the Osmia niveocincta species group. Among the representatives of this group, Osmia niveocincta Pérez, 1879 is the only species known to occur both on Crete and in Algeria. However, several characters given in the original description of Osmia cinctella clearly exclude Osmia niveocincta, suggesting that Dours’ syntypes comprised two different species. Most probably, Dours’ specimens from the Greek Islands correspond to Osmia dives Mocsaryi, 1877 and those from Algeria to Osmia frieseana Ducke, 1899. Unfortunately, the types of Osmia cinctella are lost (Tkalcu, 1977b; Zanden, 1990), rendering both the clarification of the species identity and the designation of a lectotype impossible. Thus, O. cinctella is regarded here as a nomen dubium. 

Warncke (1988a) considered the Cretean specimens of “Osmia cinctella” (as O. sogdiana cinctella) to be taxonomically different from those of Osmia dives (as O. sogdiana dives). In fact, the specimens from Crete are slightly smaller and have a slightly finer and denser punctation of female terga 1-2 compared to Osmia dives from mainland Europe and Turkey. As these morphological differences are only very minor, however, the Cretean specimens are considered here to be conspecific with Osmia dives

Taxonomy of Osmia (Pyrosmia)

Saturday, March 12th, 2022

Although Zanden (1991a) and Warncke (1992b) revised the Osmia species of the subgenus Pyrosmia, the taxonomy of the group is still in a rather poor state. The following new findings were incorporated into the Palaearctic osmiine bee website:

i) The synonymization of Osmia elbaba Warncke, 1992 with O. cyanoxantha Pérez, 1879 by Zanden (1996b) is erroneous. O. elbaba represents a species of its own differing from O. cyanoxantha in the female by the shorter ocellooccipital distance and the less densely shagreened terga 5-6 and in the male by the strongly differing pilosity and shape of the sterna and the uniformly cylindrical last antennal segment. The three specimens from northeastern Algeria, which Ferton (1914) reared from a snail shell and assumed to belong to O. leucopyga Ducke, 1899, are in fact members of O. elbaba as shown by the characters listed by Ferton, i.e. the purple scutellum (metallic green in O. leucopyga), the whitish pilosity of tergum 1 (yellowish in North African O. leucopyga) and the weakly shagreened terga 5-6 (strongly shagreened in O. leucopyga). Thus, to the present knowledge O. elbaba occurs in Morocco, Algeria and Tunisia and it nests in snail shells.

ii) The synonymization of Osmia leucopyga Ducke, 1899 with O. lobata Friese, 1899 by Warncke (1992b) is erroneous. O. lobata represents a species of its own, which is well characterized by the shagreened basal area of the propodeum (polished in O. leucopyga), and the apically emarginated median process of male tergum 7, which is unique among Osmia species of the subgenus Pyrosmia. The female from Israel described by Zanden (1991b) and keyed out in his identification key does most probably not belong to O. lobata since the author mentions that the basal area of the propodeum is polished and that the body length is only 7 mm, which appears to be too small for O. lobata, whose male holotype measures 9 mm in length. Thus, to the present knowledge O. lobata is known so far only from Algeria and no reliable records exist for the other Maghreb countries, southwestern Europe or the Levant. The nesting biology as well as the female of O. lobata are still unknown.

iii) Osmia leucopyga Ducke, 1899 was described based on a single female from Algeria. Zanden (1991b) incorporated the male of O. leucopyga in his identification key. However, the characters mentioned by him do not refer to O. leucopyga but are typical for O. elbaba Warncke, 1992, as revealed by series of both sexes of O. elbaba from the Maghreb. In 2021, T. Wood collected females of O. leucopyga at high elevations in the Sierra Nevada in southern Spain together with males, which closely correspond to the males of O. cyanoxantha Pérez, 1879. Upon closer investigation, these males were found to slightly differ from O. cyanoxantha from northern Italy and the Balkans in few characters and are thus most probably the unknown males of O. leucopyga. A pronounced morphological similarity between the males of O. cyanoxantha and O. leucopyga would not be surprising since the females of the two species are also very similar. Reliable records of O. leucopyga Ducke, 1899 exist for the Iberian Peninsula (Portugal, Spain), Morocco and Algeria, the species possibly also occurs in Tunisia. Based on two single observations, the species nests in preexisting cavities, e.g. in abandoned cells of Megachile (Chalicodoma) or in burrows in the soil (Zanden, 1991b).

iv) Osmia submicans Morawitz, 1870 is a widespread species occurring also on the Canary Islands. Here, three subspecies are recognized, i.e. O. s. canaria Mavromoustakis, 1957 (Gran Canaria, Tenerife, El Hierro), O. s. columbina Zanden, 1996 (La Palma) and O. s. lanzarotae Warncke, 1992 (Fuerteventura, Lanzarote). These three subspecies distinctly differ morphologically among each other on the one hand and with O. submicans from continental Europe on the other hand and thus probably warrant species status. However, as there are also morphological differences between members of the same subspecies inhabiting different islands (e.g. O. s. canaria on Gran Canaria and on Tenerife), these three taxa are provisionally kept as subspecies pending a new in-depth taxonomic study.

Hoplitis hyperplastica

Tuesday, February 2nd, 2021

Hoplitis hyperplastica (Morawitz, 1894) was assumed by Warncke (1991h) to be a member of the subgenus Alcidamea due to a prominent tooth on sternum 1 in the male. However, new material from Kyrgyzstan and Tajikistan revealed that H. hyperplastica is a member of the Hoplitis monstrabilis species group of the subgenus Hoplitis.

Osmia kuznetzovi

Sunday, January 3rd, 2021

Osmia (Helicosmia) kuznetzovi Cockerell, 1930 was synonymized with Osmia fasciata Latreille 1811 by Warncke (1992b). However, differences in morphology (clypeal shape, tergal punctation and fasciae, colour of scopa) and the disjunct distribution in mountaineous areas of eastern Turkey, the Levant, northern Iran and Central Asia do not support conspecifity with O. fasciata, which is a desert species ranging from the Levant over the Arabian Peninsula to Central Asia. Thus, O. kuznetzovi is tentatively regarded here as a species of its own.

Hoplitis turcestanica

Saturday, November 14th, 2020

In a recent paper, Fateryga and Proshchalykin (Caucasian Entomological Bulletin, 16, 225-231, 2020) resurrect Hoplitis (Alcidamea) turcestanica (Dalla Torre) from synonymy with Hoplitis (Alcidamea) caularis (Morawitz) as postulated by Warncke (1991h).

New Osmia (Hemiosmia) species

Friday, October 30th, 2020

An article in Zootaxa has recently been published dealing with the biology and taxonomy of Osmia bees of the subgenera Hemiosmia, Tergosmia and Erythrosmia (Zootaxa, 4778, 201-236, 2020). One new species is described: Osmia (Hemiosmia) spinicoxa spec. nov. from southwestern Morocco.