Pseudoheriades grandiceps, Peters, 1988

Gess, Sarah Kathleen & Roosenschoon, Peter Alexander, 2017, Notes on the nesting of three species of Megachilinae in the Dubai Desert Conservation Reserve, UAE, Journal of Hymenoptera Research 54, pp. 43-56 : 49-51

Pseudoheriades grandiceps

Taxonomy.

The phylogenetic position of the genus Pseudoheriades is debated. In a molecular phylogeny of the Osmiini ( Praz et al. 2008) this genus was allied with the genus Afroheriades . Both genera were not closely related to the Osmiini but formed an isolated lineage with currently uncertain phylogenetic affinities. In contrast, in cladistic analyses of morphological characters, these two genera appeared within the Heriades -group of the Osmiini although statistical support for this placement was low. Consequently, the phylogenetic placement of the Pseudoheriades / Afroheriades lineage within the megachiline phylogeny remains unsettled (see also Litman et al. 2011).

Distribution.

Saudi Arabia, United Arab Emirates, Iran, Pakistan and India ( Ungricht et al. 2008, Dathe 2009, Ascher and Pickering 2016)

Nesting.

The only published information on nesting by Pseudoheriades appears to be a brief account of the nesting biology of Pseudoheriades moricei (Friese) ( Krombein 1969; as Heriades moricei Friese) and notes on a nest of Pseudoheriades grandiceps ( Rozen and Praz 2016).

Krombein described the construction of four nests of Pseudoheriades moricei in trap-nests positioned variously on a vine-covered summer-house, a trellis and the trunk of a casuarina tree in gardens at three sites in Egypt. The cells, of the same diameter as the borings, were in linear series. The partitions capping the cells, dividing vestibular cells, and the closure of the nest were of resin or resin mixed with tiny pebbles.

The nest of Pseudoheriades grandiceps described by Rozen and Praz is based on notes, nest fragments and cocoons pinned with adults from the UAE preserved at Logan, Utah. Their figures 64 and 65 show two adults, one a female pinned with a leaf covered nest cell and a male pinned with a petal covered nest cell from which they had emerged. It was recorded that cell partitions within the leaf covering and petal covering were constructed from resin. It was not clear whether the leaves and petals had been placed by the female Pseudoheriades grandiceps or whether, as suggested by Praz, the trap-nest had been previously occupied by a different megachilid. The use of a pre-existing cavity, and the use of resin are the only similarities with the nest from the DDCR.

The notes presented here on nesting by Pseudoheriades grandiceps in the DDCR provide the first detailed observations on nest structure for this species. The nest was constructed in a trap-nest of 9.5 mm bore, part of the bundle attached near the base of the trunk of a date palm at the Camel Farm. It consisted of a cluster of cells constructed from a mixture of sand and resin. The cells free from the walls of the boring were ovoid, approximately 6 mm in length and at the widest point 3.5 mm in width with the wall approximately 1 mm in thickness. Those constructed against the Perspex cover were incompletely constructed, the Perspex forming part of the cell wall (Fig. 17a-c ).

That no leaves or petals formed part of the nests of either Pseudoheriades moricei described by Krombein nor that of Pseudoheriades grandiceps described in the present contribution confirms the suggestion that the leaves and petals present in the nest of Pseudoheriades grandiceps nest described by Rozen and Praz were present in the trap nest before the female Pseudoheriades grandiceps started her nesting activities and that she had constructed her cells within the walls of cells of another megachilid that had previously occupied the cavity. Furthermore that the cells, composing the nest of Pseudoheriades grandiceps here described, were in a boring of larger diameter than the cells and that the cells were not constructed in linear series but were grouped to form a cluster suggests that Pseudoheriades grandiceps may be found to nest in cavities other than straight borings.

Nesting progress. The first cell had been constructed by 27 April and by 2 May five cells had been constructed. Sometime later the boring was usurped for nesting by Megachile maxillosa (Fig. 13 ). When the nest was inspected in early April 2016 no imagines had emerged but by May imagines had emerged from all of the cells (Figs 18 , 19 ).

Provision. The identity of the pollen used in provisioning was not established. In order not to damage the cells the Perspex sheet was not removed until after the imagines had emerged.

Associates.

Three specimens of Zonitoschema iranica Kasab, 1959 ( Meloidae ) from Ras al-Khaymah in the United Arab Emirates were recorded as having been reared from a nest of Pseudoheriades grandiceps ( Batelka and Bologna 2014).

Figures

Figures 17 - 19. 17 a-c Cells of Pseudoheriades grandiceps in trap-nest 3 of trap-nest bundle at the Camel Farm 18 Nest of Pseudoheriades grandiceps after emergence of imagines, visible trapped between their natal nest and a nest of Megachile maxillosa which usurped trap-nest 3 19 Pseudoheriades grandiceps, imago (actual approx. 7 mm) from nest.

Figures 8 - 15. 8 Trap-nest 2 of trap-nest bundle at Tawi Ruwayyan on 27 April 2015, showing Megachile maxillosa initiating a cell 9 Trap-nest 1 of trap-nest bundle at Tawi Ruwayyan on 27 April 2015, showing two closed cells of Megachile maxillosa followed by leaf pieces, presumed to be those of a leaf cutting Megachile sp. 10 Trap-nest 2 of trap-nest bundle at Tawi Ruwayyan on 28 April 2015, showing first cell being provisioned by the builder, Megachile maxillosa 11 Trap-nest 4 of trap-nest bundle at the Camel Farm on 27 April, showing one open cell being provisioned by Megachile maxillosa 12 Trap-nest 4 of trap-nest bundle at the Camel Farm on 28 April 2016, showing two closed provisioned cells with Megachile maxillosa initiating a third cell 13 Trap nest 3 of trap-nest bundle at the Camel Farm showing nest of Pseudoheriades grandiceps at inner end followed by three-celled nest of Megachile maxillosa 14 Trap-nest 4 of trap-nest bundle at the Camel Farm showing final seal of nest of Megachile maxillosa 15 Megachile maxillosa female imago (actual length approx. 22 mm) with open cocoon.