Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 22, 2006
Publication Date: March 1, 2007
Citation: Burns, S.N., Vander Meer, R.K., Teal, P.E. 2007. Mating flight activity as dealation factors for fire ant, Solenopsis invicta, female alates. Annuals of the Entomological Society of America. 100(2):257-264. Interpretive Summary: Fire ants are noted for their high reproductive capabilities, where each colony may produce 5,000 female and male sexuals a year. When weather conditions are right the sexuals take flight and mate 400-600 feet in the air. The newly mated fire ant queens fly to the ground and almost immediately break off their wings (dealate) and search for a suitable place to dig a nuptial chamber, where she will start a new colony. While waiting in the parent colony for mating flight weather conditions the colony queen releases a chemical that that prevents the sexuals from losing their wings. If the colony queen is removed the female sexuals lose their wings within three to four days. Understanding what factors govern wing loss when the queen is removed and after a mating flight is important and could lead to novel control methods. Scientists at the Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL, and the Entomology and Nematology Department, University of Florida, Gainesville, FL have investigated the influence of several mating flight activities on female sexual wing loss. We conclude that the actual mating process is responsible for the rapid wing loss observed after mating flights. These results provide important information that could lead to methods that induce premature wing loss and decrease the fire ant's high reproductive capability.
Technical Abstract: The fire ant (Solenopsis invicta Buren) queen produces a primer pheromone that prevents dealation (wing removal) of cohabiting female alates by presumably suppressing endogenous titers of juvenile hormone (JH). Alates are released from the effects of this primer pheromone when they are separated from the queen by mating flights or death of the queen. In the former situation dealation occurs within 1h of the mating flight, whereas in the latter dealation may take several days. We investigated why the time to dealation was so different for the two conditions. A previous study showed that the dimensions of the corpora allata (CA, the source of JH) were not significantly different for newly-eclosed, mature alates, or uninseminated dealates, suggesting that size of CA do not correlate with JH production, or JH level is not a factor in dealation. No single pre-mating behavior or combination of behaviors associated with nuptial flights induced dealation rates comparable to that of newly-mated queens. Therefore, mating alone or in combination with other behavioral and/or environmental signals appears to be critical in stimulating rapid dealation in newly-inseminated alates. Dealation in the two contexts, within the colony and after mating flights, appears to occur via separate mechanisms.