It's complicated: The role of false brood cells as an anti-parasite strategy in Hymenoptera is not simple despite their ubiquity

Nest collection: Nests of A. morosus were collected from naturally abscised fronds that skirt the base of the rough fern tree, Cyathea australis in Kurth Kiln Regional Park, Yarra Ranges National Park, Cathedral Range State Park, Marysville Bushland Reserve and Grants Picnic Ground in the Dandenong Ranges region in eastern Victoria, Australia. Nests were collected across seven separate collections from December 2017 to January 2021. Collections were performed at dawn when temperatures were below 15°C to ensure all bees were in their nest. Nest entrances were sealed upon collection and nests placed on ice in insulated boxes and transported to Flinders University for nest processing.
Nest processing: Nests were opened lengthwise until the first brood cell was reached. All adult female A. morosus and any adult parasites in the nest entrance were removed and placed in 99% ethanol for preservation and identification. Nests of A. morosus can be characterized as either i) social – in which at ..., , # It's complicated: The role of false brood cells as an anti-parasite strategy in Hymenoptera is not simple despite their ubiquity

Data collection and processing:

Nest collections
In total, 299 Amphylaeus morosus stem nests were collected from abscised fronds of the rough fern tree, Cyathea australis.

Colony data
Nests were processed within 24 hours after being returned to Flinders University, and opened longitudinally up to the first brood cell, with all adult A. morosus and additional contents within the nest entrance removed and placed in 99% ethanol. The maturity of the brood cell closest to nest entrance was examined to determine if the brood were at a pupal stage where they could be visually sexed. Because A. morosus construct brood cells in a linear array, starting from “cell 1” (first brood laid – furthest from the nest entrance) to a maximum of “cell 16” (last brood laid – closest to the nest entrance) in the largest of nests, the cell closest to the nest entrance is expecte...,