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Biology

provided by Halictidae LifeDesk

The biology of Augochloropsis iris is described by Coelho (2002) from nests studied in a cloud forest at 1500 m elevation Sao Palo state, Brazil.

Augochloropsis iris’ colony cycle extends from August to March, and includes three phases of cell provisioning, separated by periods of inactivity. The bees construct tunnel nests in the soil. A short lateral tunnel connects the main burrow to a cavity that surrounds a cluster of earthen brood cells. Each cell contains one developing offspring. Cells are re-used after the emergence of offspring.

Nests are typically initiated by solitary females who have overwintered (May-July) after mating in March. These females construct cells and provision offspring with pollen from August to October. The daughters who emerge from this first brood in November may stay in the nest as non-reproductive workers, foraging for pollen for the second brood of offspring of their mother, the queen, who reproduces and never leaves the nest. Or they may disperse and initiate their own nests. Or they may work to provision the second brood of offspring, and then leave to disperse and initiate their own nests. The original queens, as well as the new foundresses, each provision a brood of offspring during the second phase of provisioning, from December to January. Again, female offspring from the second brood may stay as workers or disperse to initiate their own nests; approximately 50% dispersed to initiate their own nest. Queens and new foundresses provision a third phase of offspring in February, which emerges in March. These females mate, dig their own nests, and wait there in diapause until the following August to begin the cycle again. Queens—those females who initiate a nest after overwintering—average 5% larger than workers. In general, workers are mated but do not have developed ovaries.

First phase nests were typically solitary (with 2.33 average cells), but about one quarter contained multiple females (up to 4, average 2.3, with 5.6 average cells). Second and third phase nests contained about 3 females (up to 5), and 5 cells.

Nests were attacked by mutillid wasps of the genus Sphinctopsis, which evicted the bees from the nest, phorid flies, and ants.

The offspring sex ratio was heavily female biased, and new solitary nests initiated by females who left the foundress-initiated nests produced exclusively female offspring.

Workers can work, then leave to initiate nest.

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Smith, Adam
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Smith, Adam
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