Myrmecol. News 19: 93-102; printable
- DOI: https://doi.org/10.25849/myrmecol.news_019:093
- Open Access: CC BY 4.0
- Year: 2014
- Title: Initiation of swarming behavior and synchronization of mating flights in the leaf-cutting ant Atta vollenweideri FOREL, 1893 (Hymenoptera: Formicidae)
- Journal: Myrmecological News
- Volume: 19
- Pages: 93-102
- Type of contribution: Original Article
- Supplementary material: Yes
- Abstract: Leaf-cutting ants of the genus Atta build giant nests, inhabited by millions of workers. During a few days in spring, thousands of alates leave their mature home colonies for their mating flights. These flights are synchronized on a large geographical scale, and weather conditions have been reported to play a crucial role in determining when mating flights occur. Nevertheless, many fundamental aspects of the fascinating swarming behavior in Atta are unknown. In this study we describe the three successive phases of the swarming behavior of A. vollenweideri Forel, 1893, the initiation phase, the aggregation phase, and the mating flight. Prior to take-off, alates of both sexes exhibit distinct pre-flight behaviors. Atta vollenweideri is a day-flying species, with mating flights occurring in the late afternoon before dusk, and it is the southernmost species of the genus, experiencing strong seasonal climate. In order to identify climatic parameters that induce swarming behavior and elicit a synchronized mating flight, we analyzed 23 swarm events and the corresponding climate data from 2004 - 2010 recorded in northern Argentina. Colonies prepare for mating flights in the spring after a cumulative precipitation of at least 64 mm in the last month before the first mating flight. Only if temperatures rise above 26°C on the days following a major rainfall, alates may leave the nest mound, although they prefer temperatures of about 32°C. When accounted for together, rainfall and a subsequent temperature increase are highly predictive and thus prerequisites for swarming behavior in this species. We propose that Atta species have based on the preferred depth of the founding chamber and local soil conditions speciesspecific thresholds for cumulative precipitation. In A. vollenweideri, the heavy clay soils that are desiccated after the austral winter select for mating flights and subsequent colony founding only after very high precipitation.
- Key words: Atta vollenweideri, leaf-cutting ants, weather induction, synchronization, Formicidae, mating flight.
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: Print: 1994-4136 - Online: 1997-3500
Myrmecol. News 19: 93-102; Appendix S1_Males displaying sex-specific preflight behavior
- Open Access: CC BY 4.0
- Journal: Myrmecological News
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: Print: 1994-4136 - Online: 1997-3500
Myrmecol. News 19: 93-102; Appendix S2_Nest densely covered with males during late aggregation phase, just prior the start of a mating flight
- Open Access: CC BY 4.0
- Journal: Myrmecological News
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: Print: 1994-4136 - Online: 1997-3500
Myrmecol. News 19: 93-102; Appendix S3_Gynes departing from central nest entrances
- Open Access: CC BY 4.0
- Journal: Myrmecological News
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: Print: 1994-4136 - Online: 1997-3500
Myrmecol. News 19: 93-102; Appendix S4_Individual gyne displaying sex-specific preflight behavior
- Open Access: CC BY 4.0
- Journal: Myrmecological News
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: Print: 1994-4136 - Online: 1997-3500
Myrmecol. News 19: 93-102; Appendix S5_Yellow-Headed Caracara (Milvago chimachima VIEILLOT, 1816) catching an airborne gyne during a mating flight
- Open Access: CC BY 4.0
- Journal: Myrmecological News
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: Print: 1994-4136 - Online: 1997-3500