Ptiloglossa matutina (Schrottky, 1904)

Sarzetti, Laura C., Genise, Jorge F., Sanchez, M. Victoria, Farina, Juan L. & Molina, M. Alejandra, 2013, Nesting behavior and ecological preferences of five Diphaglossinae species (Hymenoptera, Apoidea, Colletidae) from Argentina and Chile, Journal of Hymenoptera Research 33, pp. 63-82 : 68-69

Ptiloglossa matutina (Schrottky, 1904)

Locality and nesting site.

Observations were carried out during 2012 on March 11th and November 10th in the Karadya Bioreserve (25°52.233'S, 53°58.167'W), near Andresito, Misiones province, Argentina ( Fig. 24 ). The locality is included in the Upper Paraná Atlantic Forest Region. The climate is warm subtropical, without a dry season, MAT around 20° C and a MAP around 2000 mm (Servicio Meteorológico Nacional, 2012). During March, 11th, males of Ptiloglossa matutina were collected, probably before their emergence, inside tunnels exposed in a soil vertical section. On November 10th, one nest was excavated in a patch of lateritic soil, altered by human activities, containing abundant roots, litter, and some rocks.

Daily activity.

The nest was excavated at midday and the female was found inside the main tunnel. Some weeks ago, similar nests were observed with the entrance open and females flying close to them after 06:00 pm ( Julián Baigorria, pers. comm.).

Description of the nest.

The entrance was circular, 0.7 cm in diameter, without tumulus, and closed by a soil plug ( Fig. 25 ). The main tunnel was circular in cross section, 25 cm long, nearly straight and slightly inclined downwards ( Figs 21 and 26 ). It was 0.6-0.7 in maximum diameter. The nest contained four closed cells. One pair at a depth of 20 cm, were possibly connected to the main tunnel by a common tunnel filled with soil, 3 cm long. The other two cells, at a depth of 26 cm, were located at the other side of the main tunnel and also 3-4 cm of it ( Fig. 26 ). The cells were vertical, rounded at the bottom and the neck was strongly curved ( Figs 27 and 29 ). The vertical portion of the cell was 2.3 cm long and 1.3 cm in maximum diameter (n: 4). The neck was 0.8 cm in diameter (n: 4). The inner surface of cells and the neck were lined with a whitish semitransparent, cellophane-like material ( Figs 27 and 28 ). Three cells contained eggs and one a young larva ( Figs 27 and 28 ). The eggs, whitish, cylindrical and lightly curved, were 2.8 mm long and 0.4 mm wide. They laid on top of the yellow semiliquid provisions. The young larva was also whitish, curved, and almost submerged in the provisions. An earthen cell closure was not observed. Instead, a closure of white, cotton-like material that seems to be spirally arranged was observed ( Fig. 28 ).

Figures

Figures 24 - 29. Ptiloglossa matutina (Schrottky, 1904). 24 General view of the nesting site at Reserva Karadya, Andresito (Misiones province) 25 Nest entrance closed by a plug of soil (arrow), scale line: 1 cm 26 Soil with roots, litter, some rocks, and remains of the main tunnel (arrow) 27 Cell showing the larva partially submerged in provisions, cellophane lining, and the wad cotton-like material attached the cell closure, scale line: 0.5 cm 28 Detail of the cell closure with the cotton-like material 29 Cell and neck wall with the lining removed. Note the high curvature.

Figures 19 - 23. 19 Nest architecture of Ptiloglossa tarsata (Friese, 1900). 20 Cell with provisions and egg, cell neck, spiral closure, and entrance tunnel of Ptiloglossa tarsata 21 Nest architecture of Ptiloglossa matutina (Schrottky, 1904) 22 Nest architecture of Cadeguala albopilosa (Spinola, 1851) 23 Cell with provisions and egg, cell neck, location of the cell closure and entrance tunnel of Cadeguala albopilosa.