Rhodanthidium siculum (Spinola, 1838)

Hostinska, Lucie, Kunes, Petr, Hadrava, Jiri, Bosch, Jordi, Scaramozzino, Pier Luigi & Bogusch, Petr, 2021, Comparative biology of four Rhodanthidium species (Hymenoptera, Megachilidae) that nest in snail shells, Journal of Hymenoptera Research 85, pp. 11-28 : 11

Rhodanthidium siculum

Material examined.

Two nests from Sicily.

Nest structure.

The nests of this species contained only one brood cell. The vestibular space had no inner partition and, unlike the two previous species, was not filled with debris (Fig. 2G ). The closing plug was made of resin with small fragments of snail shells and sand particles (Fig. 2F ).

Shell choice.

One nest was built in an E. vermiculata shell, and the other was built in a T. pisana shell.

Life cycle.

In May, both nests contained young feeding larvae. Adult eclosion occurred in August.

Nest associates.

No nest associates were recorded for this species.

Pollens collected.

We analysed pollen from one nest. We identified nine pollen types from five plant families. The main plant family was Asteraceae (62%, mostly Anthemis arvensis but also Centaurea jacea ), followed by Fagaceae (32%, mostly Castanea ) (Fig. 4 and Suppl. material 3: Table S3). These results indicate that this species is also polylectic.

Figures

Figure 2. Photos and schematic drawings of nests of four species of Rhodanthidium. Rhodanthidium septemdentatum A shell of Caucasotachea vindobonensis with closing plug made of resin B schematic drawing of the inner nest structure in the shell. Rhodanthidium sticticum C shell of Eobania vermiculata with closing plug made of resin and soil particles D schematic drawing of the inner nest structure in the shell E photo of the shell with larva, pollen and filling of stones and plant partitions. Rhodanthidium siculum F shell of Eobania vermiculata with closing plug made of resin, sand and shell particles G schematic drawing of the inner nest structure in the shell. Rhodanthidium infuscatum H schematic drawing of the inner nest structure in the shell.

Figure 4. Proportions (in %) of pollen grains of plant families in studied nests of three species of Rhodanthidium.