Messor barbarus: the autumn harvester flights

In Iberia, Messor barbarus is an ant to watch after autumn rain. Its main flight season falls in September and October.

Gómez and Abril's Iberian study collected 123 flight observations from 2003–2009. Of those, 93% fell within a seven-week period in September and October. The authors identified eight clusters lasting three to five days. Observation sites in the widest cluster were 1,075 km (668 miles) apart; that measures the spread of reports, not how far an individual ant flew.

The busiest days generally came two or three days after a cluster began. In the two weather sequences illustrated, rain had stopped and the fronts had moved away by the peak. This does not establish a universal countdown from the last raindrop. The authors also acknowledge possible identification errors in the community observations.

During September and October, check nearby nests as the weather clears after rain. Note when the rain ended and when you visited. If you visit a nest, record whether you saw workers, winged ants at the entrance or ants actually taking off. Those are different observations.

Photograph what you see before settling on a species name. A nearby seed trail is useful context, but it isn't an identification of every winged ant on the pavement. Include a side view and a view from above where possible, and keep the date and location with the photographs. The queen-identification guide shows which body parts to look at.

If you intend to keep a queen, prepare a water-filled test tube with a cotton barrier and check local collection rules before going out. Our test-tube guide covers the water reservoir and leak check; it doesn't replace species-specific advice about feeding or winter care.

For a regional outlook, use Dealate alongside your own observations. A low score and a nest full of departing ants are worth recording together. Keep the original observation even when it disagrees with the forecast.

Gómez, C. & Abril, S. (2012). Nuptial flights of the seed-harvester ant Messor barbarus (Linnaeus, 1767) (Hymenoptera: Formicidae) in the Iberian Peninsula: synchrony, spatial scale and weather conditions. Myrmecological News 16: 25–29. Published online 30 June 2011. Full paper.