Glossamegilla Brooks, 1988

Carion, Frédéric, Gérard, Maxence, Ghisbain, Guillaume & Wood, Thomas J., 2025, Unravelling Amegilla (Glossamegilla) diversity across the Wallace Line: new species, wing morphometrics, and biogeographic boundaries (Hymenoptera, Apidae), ZooKeys 1256, pp. 1-79 : 1-79

publication ID	https://doi.org/10.3897/zookeys.1256.162903
publication LSID	lsid:zoobank.org:pub:48BDF6F0-D09A-47C6-9FFD-6B300243BF6E
DOI	https://doi.org/10.5281/zenodo.17371520
persistent identifier	https://treatment.plazi.org/id/787EDBB5-1AC0-54B4-B48D-533E58CD5089
treatment provided by	ZooKeys by Pensoft
scientific name	Glossamegilla Brooks, 1988
status

Treatment

Diagnosis of the subgenus Glossamegilla Brooks, 1988

Diagnosis.

Male: The male is the most straightforward sex to determine the subgenus but the eighth sternum and the genitalia must be extracted to ensure correct identifications.

The revised diagnosis, based on a revision of Brooks’ (1988) characters, is: species restricted to south-east or eastern Asia, mainly distributed in the Indo-Malayan region (no species of this subgenus are found in Australia). The subgenus Glossamegilla can be distinguished from the subgenus Micramegilla Brooks, 1988 by (i) the long galea which reaches at least the middle of the midcoxa when resting, the galea is ≥ 3 × as long as the foretibia when measured from the apex to the maxillary palpus ( Micramegilla have a moderately long galea which reach at most the anterior edge of the midcoxa when resting; the galea, with the same measurement method, is ≤ 2.5 × as long as the foretibia) and (ii) the S 8 that is apicomedially emarginate between a pair of large obtuse lobes (while Micramegilla have a S 8 apicomedially relatively narrowly emarginate between a pair of small obtuse lobes or with only a single median lobe). The subgenera Glossamegilla and Micramegilla also have different geographical distribution with Glossamegilla containing mainly Indo-Malayan species and Micramegilla containing mainly Palaearctic and Afrotropical species. These two subgenera only overlap in India, where the three Indian Glossamegilla have at least a length of 13 mm and entirely black haired terga or at least the anterior 1 / 2 orange haired but the Indian Micramegilla species have a length of ≤ 12 mm and terga with pale hair bands apically. Glossamegilla can be differentiated from the subgenera Amegilla Friese, 1897 sensu stricto, Notomegilla Brooks, 1988 , Asaropoda Cockerell, 1926 , Zonamegilla Popov, 1950 , Dizonamegilla Brooks, 1988 , and Zebramegilla Brook, 1988 by a generally wide apex of S 8, that is also emarginate and bilobed with two blunt lobes, leading to a generally rectangular-shaped sternum in dorsal or ventral view (Fig. 6 H View Figure 6 ) (while the other subgenera cited have a narrower apex of S 8, that is either bilobed or rounded, leading to a triangle-shaped sternum in dorsal or ventral view). Glossamegilla can be differentiated from Ackmonopsis Brooks, 1988 , Aframegilla Popov, 1950 and Megamegilla Brooks, 1988 by the absent gonostyli (Figs 6 G View Figure 6 , 9 G View Figure 9 , 10 H View Figure 10 , 11 G View Figure 11 ) (while the three other subgenera have gonostyli that are various in size and shape but always present).

Usually, the long galea is a good character to determine the subgenus Glossamegilla , as the galea is ≥ 3 × as long as the foretibia (reaching to at least the middle of the midcoxa when resting), and this can help a lot for the determination as no other subgenera (especially in the Indo-Malayan region) have such a long galea.

Female: There is a lack of strong morphological diagnostic characters in the females, and the main characters used are based on colouration, which varies strongly. Michener (2007) described the subgenera of Amegilla as “ largely indistinguishable in females, and in males differ from one another considerably less than do most subgenera of Anthophora ”. He however stated that the high species richness of the genus would support the recognition of subgenera, and that names were available for use by workers. A complete morphologic and genetic revision of Amegilla subgenera should therefore be made in order to validate the concepts used by Brooks and find stronger characters to diagnose them.

The revised diagnosis, based on a revision of Brooks’ (1988) characters, is: Firstly, some species of the subgenus Glossamegilla have metallic hairs of various colours on the metasoma (e. g., A. hanitschi (Meade-Waldo, 1914) with the terga entirely and evenly covered by green metallic hairs), these species can be differentiated from the subgenera Aframegilla (partim), Notomegilla , and Zonamegilla (partim) by a long galea that reaches at least to the middle of the hind coxa when resting, the galea is ~ 3 × as long as the foretibia when measured from the apex to the maxillary palpus (while the three other subgenera have a short to moderate galea that reach at most the anterior edge of the hind coxa and is ≤ 2.5 × as long as the foretibia with the same type of measurement), the absence of paraocular marks (while these marks are present in the three other subgenera) as well as the biogeography (indeed, the Glossamegilla with metallic hairs like A. hanitschi are an Indo-Malayan group while Aframegilla is an African group, Notomegilla is an Australian group and Zonamegilla is a more widespread group distributed in the Indo-Malayan and Australian regions).

The second group of Glossamegilla does not have any metallic hairs on the terga. The latter either show pale hair bands that contrast black hairs on the tergal discs, are entirely covered by pale pubescence, or show another type of black and pale hairs mixing (Figs 5 F View Figure 5 , 7 F View Figure 7 , 8 F View Figure 8 , 9 F View Figure 9 , 10 F View Figure 10 , 11 F View Figure 11 , 12 D View Figure 12 , 13 D View Figure 13 , 14 E, F View Figure 14 , 17 F View Figure 17 , 18 F View Figure 18 , 19 F View Figure 19 , 20 F View Figure 20 , 21 F View Figure 21 , 22 F View Figure 22 , 23 F View Figure 23 , 24 F View Figure 24 ). The pale hairs can vary from white (e. g., A. sumatrana and A. jacobi ( Lieftinck, 1944) (Figs 21 F View Figure 21 , 24 F View Figure 24 )) to bright orange (e. g., A. feronia , Fig. 20 F View Figure 20 ). In this group, the paraocular marks can be either absent or present but the maxillary palpi always have six segments.

If pale paraocular marks are absent, Glossamegilla can be distinguished from Asaropoda by the biogeography ( Glossamegilla have an Indo-Malayan distribution, mainly in the Indo-Malayan region while ( Asaropoda ) is restricted to Australia) and the pale clypeal marks that are an inverted T-shape or the clypeus can also be entirely to almost entirely black for Glossamegilla (Figs 7 C View Figure 7 , 12 C View Figure 12 , 13 C View Figure 13 ) (while Asaropoda have a clypeus almost entirely pale, except for the small dark mark at the anterior tentorial pits). Glossamegilla can be differentiated from Ackmonopsis (partim), Micramegilla (partim) and Amegilla sensu stricto (partim) by the absence of hair bands on the apical margin of some terga and / or with some or all terga covered by dense and appressed pubescence (Figs 12 D View Figure 12 , 13 D View Figure 13 , 17 F View Figure 17 for example) (while the three other subgenera have all the terga with a hair band on the apical margin, these hair bands can be white to ochraceous). Glossamegilla can be differentiated from Megamegilla and Ackmonopsis by the pubescence of the mesosoma that can be ochraceous, fulvous, orange, bright orange, brown or even black with more or less black hairs intermixed (while the two other subgenera have a mesosoma with brown to orange hairs with more or less black hairs intermixed) (Fig. 7 B View Figure 7 ) as well as terga with hair bands on the apical margins, basally covered by black pubescence on the discs, or entirely covered by pale pubescence of various colour on at least T 2-4 (Fig. 7 F View Figure 7 ) (while the two other subgenera have black hairs on almost all the terga except T 3-5 that have portion of the apical margins with appressed white hairs). Finally, Glossamegilla can be distinguished from Micramegilla , Amegilla sensu stricto (partim), Zebramegilla , Megamegilla (partim) and Aframegilla (partim) by the Indo-Malayan distribution (this group of species are mainly distributed in India while the other subgenera are distributed in the Palaearctic and in Africa) and by the clypeus entirely black except sometimes with a small mark basomedially (while the other subgenera have more extended pale clypeal marks compound of an inverted T-shape or a median longitudinal line, only the species from Cape Verde Islands have an entirely black clypeus).

If pale paraocular marks are present (Figs 5 C View Figure 5 , 8 C View Figure 8 , 9 C View Figure 9 , 17 C View Figure 17 , 18 C View Figure 18 , 19 C View Figure 19 , 20 C View Figure 20 , 21 C View Figure 21 , 22 C View Figure 22 , 23 C View Figure 23 , 24 C View Figure 24 ), the Glossamegilla can be separated from Zebramegilla (partim), the Micramegilla (partim) and the Dizonamegilla (partim) by their Indo-Malayan distribution while the other subgenera are distributed in Africa and Western Palaearctic. T 1-2 can be either entirely black haired without pale hair bands on the apical margins nor appressed brown hairs (sometimes sides of the T 2 can be covered by tuft of white hairs) (Fig. 21 F View Figure 21 ) or banded with pale hairs on the apical margins (sometimes the T 2 have poorly developed hair bands) (Figs 5 F View Figure 5 , 7 F View Figure 7 , 10 F View Figure 10 , 18 F View Figure 18 , 19 F View Figure 19 , 20 F View Figure 20 , 23 F View Figure 23 , 24 F View Figure 24 ), sometimes most of T 1-2 are covered by adpressed brown hairs that can be sometimes very sparse or absent medially.

If T 1-2 are entirely black haired without pale hair bands on the apical margins nor appressed brown hairs (sometimes sides of the T 2 can be covered by tuft of white hairs), Glossamegilla can be separated from the Dizonamegilla (partim) by the terga being entirely black haired, except for tufts of white hairs on the sides of T 5.

If T 1-2 are banded with pale hairs on the apical margins (sometimes the T 2 have poorly developed hair bands and sometimes most of T 1-2 are covered by adpressed brown hairs that can be sometimes very sparse or absent medially), the Glossamegilla can be differentiated from the Zonamegilla (partim) and Zebramegilla (partim) by (i) a body length of at least 12 mm (while the two other subgenera have a length of ≤ 9 mm), (ii) the mesosoma with ochraceous to bright orange hairs with more or less or without black hairs intermixed (Figs 5 B View Figure 5 , 7 B View Figure 7 , 10 B View Figure 10 , 18 B View Figure 18 , 19 B View Figure 19 , 20 B View Figure 20 , 23 B View Figure 23 , 24 B View Figure 24 ) (while the two others subgenera have a mainly white haired mesosoma with some black hairs intermixed) and (iii) with pale hair bands on the apical margins of the terga that are generally brown (but can also be ochraceous to bright orange) while the discs is at least partially black haired or terga entirely covered by ochraceous to fulvous or brown pubescence that is sometimes denser apically, leading to slightly contrasting hair bands (Figs 5 F View Figure 5 , 7 F View Figure 7 , 8 F View Figure 8 , 9 F View Figure 9 , 10 F View Figure 10 , 17 F View Figure 17 , 18 F View Figure 18 , 19 F View Figure 19 , 20 F View Figure 20 , 22 D View Figure 22 , 23 F View Figure 23 , 24 F View Figure 24 ) (while the two others subgenera have pale hair bands on the apical margins of the terga).

As previously said, the females are more difficult to determine at the subgenus-level as mainly colouration-based characters are used and these characters vary substantially. However, the biogeographic regions and the size of the galea (that reaches at least the middle of the hind coxa when resting, with the galea ~ 3 × as long as the foretibia when measured from the apex to the maxillary palpus) are powerful diagnostic characters.