Megaloptilla Moure and Hurd

ENGEL, MICHAEL S., 2000, Classification Of The Bee Tribe Augochlorini (Hymenoptera: Halictidae), Bulletin of the American Museum of Natural History 2000 (250), pp. 1-89 : 42-44

Genus Megaloptilla Moure and Hurd

Megommation (Megaloptilla) Moure and Hurd, 1987: 241 . Type species: Halictus callopis Vachal, 1911 , monobasic and original designation.

Emgaloptilla Moure and Hurd, 1987: vi. Lapsus calami.

DIAGNOSIS: The genus Megaloptilla is most similar to as well as most closely related to Paroxystoglossa . Megaloptilla can be separated from Paroxystoglossa , however, by a rounded preoccipital ridge, a transverse labral basal elevation, an acute marginal cell apex, and a very weakly narrowed anterior border of the mesoscutum.

DESCRIPTION: Female. Mandible bidentate, with weak supplementary teeth. Labral distal process narrowly triangular; basal elevation transverse; teeth weak. Prementum not greatly elongate. Galeal apex rounded; galeal comb absent; galeal base extending to stipital base. Hypostomal ridge carinate; anterior angle rounded. Length of malar space less than basal mandibular width. Epistomal sulcus orthogonal. Ocelli not greatly enlarged; ocellar furrow absent. Vertex not expanded or ridge behind ocelli. Preoccipital ridge rounded. Pronotal lateral angle not produced, obtuse; dorsal ridge carinate, weakly lamellate in some places; lateral ridge rounded. Mesoscutal anterior border slightly narrowed; mesoscutal lip rounded. Tegula oval. Anterior basitarsal brush present. Basitibial plate bordered on all sides. Inner hind tibial spur serrate. Apex of marginal cell acute. Distal hamuli with irregular spacing pattern. Basal area of propodeum subequal to scutellum, rugulose; propodeal pit narrow. Male. Mandible simple. Labrum without distal process; no elevation. Antenna extending back to scutellum; F2 longer than F1. Inner hind tibial spur serrate. Metasoma oval. Apical margin of S4 unmodified. Apical margin of S5 weakly emarginate. Apical margin of S6 emarginate. Apical margin of S7 with median projection. Apical margin of S8 with bilobed median projection; spiculum narrow. Proctiger unmodified. Gonobasal bridge narrow; dorsal lobes weak. Parapenial lobe and basal process of gonostylus absent. Ventral surface of penis valve unmodified.

REVISIONS: Engel and Brooks (1999a) have recently revised Megaloptilla and recognized two species: Megaloptilla callopis (Vachal) and M. byronella Engel and Brooks.

DISTRIBUTION: Megaloptilla callopis is recorded from Colombia, Ecuador, and Peru while the second species is presently known only from Panama.

Genus Megommation Moure

DIAGNOSIS: This is a heterogenous group of taxa with strongly narrowed mouthparts (e.g., Megaloptidia , Ariphanarthra ). Megommation in the broad sense can be most easily separated from these other genera by normalsized compound eyes (greatly enlarged in Megaloptidia ) and normal maxillary palpi (greatly lengthened in Ariphanarthra ). See also the diagnoses for Megaloptidia , Ariphanarthra , and Micrommation .

DESCRIPTION: Female. Labral distal process broadly triangular. Prementum greatly elongate. Galeal apex acute; galeal comb absent; galeal base extending to stipital base. Hypostomal ridge carinate to weakly lamellate; anterior angle rounded. Length of malar space less than basal mandibular width. Epistomal sulcus orthogonal. Ocellar furrow absent. Vertex not expanded or ridged behind ocelli. Preoccipital ridge rounded. Pronotal lateral angle not produced, obtuse; lateral ridge rounded. Mesoscutal anterior border rounded; mesoscutal lip rounded. Tegula oval. Anterior basitarsal brush absent. Apex of marginal cell acute. Distal hamuli with irregular spacing pattern. Male. Mandible simple. Inner hind tibial spur serrate. Gonobasal bridge narrow; dorsal lobes strong. Apical margin of S6 emarginate. Proctiger with anal filaments. Basal process of gonostylus absent; parapenial lobe present; dorsal process of gonostylus partially membranous. Ventral surface of penis valve with prong.

Subgenus Cleptommation

Engel, Brooks, and Yanega

Figures 3 , 12 , 13, 15 , 32 , 38 , 45 , 51 Megommation (Cleptommation) Engel, Brooks, and Yanega, 1997: 19 . Type species: Megalopta minuta Friese, 1926 , monobasic and original designation. DIAGNOSIS: This cleptoparasitic subgenus can be quickly identified by the simple, bladelike mandibles (fig. 15), the absence of a basitibial plate, and the absence of a scopa. It is most similar to Megaloptina , both sharing the dense, plumose setae surrounding the propodeal spiracle in males. Megaloptina , however, is not parasitic and has a well-developed scopa, a basitibial plate, and normal mandibles. The serrate inner metatibial spur also distinguishes Cleptommation from Megaloptina .

DESCRIPTION: As for the genus with the following additions: Female. Mandible simple, bladelike (fig. 15). Labral basal elevation absent; teeth absent. Clypeal apex relatively straight. Hypostomal ridge carinate. Ocelli not greatly enlarged. Pronotal dorsal ridge rounded. Mesoscutal anterior border round- ed; mesoscutal lip rounded. Scopa absent Basitibial plate absent. Inner hind tibial spur serrate. Male. Labrum without distal process basal area not notched. Antenna extending back to scutellum or metanotum; F1 longer than F2. Dense patch of plumose setae at propodeal spiracle. Metasoma slightly elongate. Apical margins of S2 and S3 with slight median projection. Apical margins of S4 and S5 unmodified. Apical margins of S7 and S8 with median process.

REVISIONS: There is only one included species, although there may be a second species (R. W. Brooks, personal commun.; D. Yanega, personal commun.).

BIOLOGY: Based on the adult anatomy Cleptommation is cleptoparasitic, perhaps on other species of Megommation (most likely Megaloptina or Stilbochlora ).

DISTRIBUTION: Cleptommation occurs in Bolivia, Brazil, Costa Rica, Ecuador, Panama, and Peru.

Subgenus Megaloptina Eickwort Figures 5 , 12–13

Megommation (Megaloptina) Eickwort, 1969a 441. Type species: Augochlora (Pseudaugochloropsis) ogilviei Cockerell, 1930 , original designation.

DIAGNOSIS: This subgenus is most similar to Cleptommation , particularly in the male sex where both share the presence of dense plumose setae surrounding the propodeal spiracle. Cleptommation , however, lacks a scopa, has a bladelike mandible, lacks a basitibial plate, and differs in the structure of the male metasomal sterna. Megaloptina differs from Stilbochlora in the presence of a propodeal tuft of setae in males and the short basitibial plate with weakly developed borders.

DESCRIPTION: As for the genus with the following additions: Female. Mandible with moderate subapical tooth. Labral basal elevation orbicular; teeth weak. Clypeal apex concave (fig. 12). Hypostomal ridge carinate. Ocelli not greatly enlarged. Pronotal dorsal ridge rounded. Scopa present. Basitibial plate extremely short, borders faint. Inner hind tibial spur pectinate. Male. Labrum without distal process. Antenna extending back to scutellum; F1 longer than F2. Dense patch of plumose setae at propodeal spiracle. Metasoma oval. Apical margin of S2 unmodified. Apical margin of S3 with median projection. Apical margin of S4 unmodified. Apical margin of S5 emarginate. Apical margin of S7 with median projection. Apical margin of S8 unmodified.

REVISIONS: There are presently only two described species, Megommation festivagum (Dalla Torre) and M. ogilviei (Cockerell) , and at least one undescribed species (personal obs.).

DISTRIBUTION: Megaloptina is known from Ecuador, Guyana, and Brazil.

Figures

Figs. 1–6. Heads of Augochlorini, frontal aspect. 1. Thectochlora alaris (Vachal), female. 2. Rhinocorynura briseis (Smith), female. 3. Megommation (Cleptommation) minutum (Friese), female. 4 Chlerogella sp., female. 5. M. (Megaloptina) ogilviei (Cockerell), female. 6. Megalopta (Megalopta genalis Meade-Waldo, male.

Figs. 7–12. Head modifications of female Augochlorini. 7. Temnosoma metallicum Smith, dorsal aspect. 8. T. metallicum, profile. 9. T. metallicum, vertex. 10. Pseudaugochlora graminea (Fabricius), vertex. 11. Megalopta (Megalopta) genalis Meade-Waldo, vertex. 12. Clypeal apex of Megommation (Megaloptina) ogilviei (Cockerell).

Figs. 13–16. Female mouthparts. 13. Labiomaxillary complex and hypostomal fossa of Megommation (Megaloptina) ogilviei (Cockerell), ventral aspect. 14. Labiomaxillary complex and hypostomal fossa of Corynura (Corynura) chilensis (Spinola), ventral aspect. 15. Clypeus and mandibles of M (Cleptommation) minutum (Friese). 16. Mandible of Megalopta (Megalopta) genalis Meade-Waldo.

Figs. 30–33. Mesosomae of female Augochlorini. 30. Temnosoma metallicum Smith, profile. 31 Rhinocorynura briseis (Smith), profile. 32. Mesoscutum of Megommation (Cleptommation) minutum (Friese), dorsal aspect. 33. Mesoscutum of R. briseis, dorsal aspect, pronotal dorsal lamellae evident on upper corners of mesosoma.

Figs. 38–41. Features of female Augochlorini. 38. Scutellum, metanotum, and basal area of propodeum of Megommation (Cleptommation) minutum (Friese). 39. Scutellum, metanotum, and basal area of propodeum of Chlerogella sp. 40. Hind leg of Temnosoma metallicum Smith, scopa absent from femur and tibia. 41. Hind leg of Augochlora (Augochlora) pura (Say), scopa on femur and tibia.

Figs. 42–45. Leg modifications of female Augochlorini. 42. Inner surface of mesotrochanter of Thectochlora alaris (Vachal) showing hook on dorsal surface. 43. Basitibial plate of Augochlora (Augochlora) pura (Say). 44. Basitibial plate of T. alaris. 45. Outer surface of metatibial base of Megommation (Cleptommation) minutum (Friese), showing absence of basitibial plate.

Figs. 46–51. Spurs and antenna cleaners of female Augochlorini. 46. Inner hind tibial spur of Chlerogella sp. 47. Inner hind tibial spur of Thectochlora alaris (Vachal). 48. Inner hind tibial spur of Augochlora (Augochlora) pura (Say). 49. Inner hind tibial spur of Pereirapis semiaurata (Spinola). 50 Antenna cleaner of Chlerogella sp. 51. Antenna cleaner of Megommation (Cleptommation) minutum (Friese).