Trophic eggs in three ponerine ant species: Harpegnathos venator, Odontomachus simillimus and Odontoponera denticulata

Trophic eggs in ants have been well known for a long time, however, published infor-mation of trophic eggs in poneroid ants is relatively scarce. We observed the production and fate of trophic eggs in relation to female castes and reproductive status in three species of ponerine ants in SE Asia. In all species, trophic eggs were principally offered to and eaten by reproductive females. When the trophic eggs were refused by reproductive females, other colony members fed on the trophic eggs. Reproductive females of the three species fed on both insect prey and trophic eggs, however, the proportion of time spent eating the two types of prey varied among species and also among colonies. In Harpegnathos venator, trophic eggs were laid by non-reproductive females including virgin work-ers, virgin queens, and mated but infertile workers. All trophic eggs were eaten by mated queens or gamergates (mated and egg-laying workers). The rate of trophic egg laying was as low as 0.0187 +/- SD 0.0110 per individual per hour (i.e. on average one egg every two days 5 hours 29 min.). In Odonto-ponera denticulata, workers laid on average 0.0115 +/- 0.009 trophic eggs per worker per hour (i.e. one egg every three days 14 hours 57 min.). All egg laying workers first brought trophic eggs to queens, but queens fed on only ca. 20% of the trophic eggs. Furthermore, queens rarely showed complete feed-ing. In most cases, queens ate the eggs halfway through and dumped the rest. These dumped eggs were picked up by workers, and given to larvae or eaten by workers. In Odontomachus simillimus, queen feeding behavior varied from insect prey to trophic eggs depending on colony growth stage. When the colony was large, workers laid trophic eggs at a low rate of 0.0035/individual/hour (i.e. one egg every 11 days 21 hours 43 min.) and most trophic eggs laid by workers were eaten by the queen.

Automated summary

There are variations in the production and fate of trophic eggs among different species of ponerine ants. Non-reproductive females usually lay trophic eggs, which are then consumed by mated queens or gamergates. The type and proportion of food consumed by reproductive females vary among different species and colonies.