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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Imported Fire Ant and Household Insects Research » Research » Publications at this Location » Publication #189436
Title: Oviposition Process of Solenopsis invicta (Hymenoptera: Formicidae) Queens

Author
item Vander Meer, Robert - Bob
item MOREL, LAURENCE - UNIVERSITY OF FLORIDA

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2006
Publication Date: 9/1/2007
Citation: Vander Meer, R.K., Morel, L. 2007. Oviposition Process of Solenopsis invicta (Hymenoptera: Formicidae) Queens. Annuals of the Entomological Society of America.100(5):758-762.

Interpretive Summary: The fire ant is a multi-billion dollar problem in the United States, affecting the general public, wildlife, and agriculture. Much of the success of the fire ant can be attributed to huge population levels that are maintained through high queen egg-laying rates. Knowing more about the egg-laying mechanism is important in understanding the population dynamics of this invasive ant species. Previously we determined that the queen deposits antimicrobial compounds and a worker attractant on the eggs as they are laid. Scientists at the Center for Medical, Agricultural and Veterinary Entomology, USDA, ARS, Gainesville, Florida describe here the egg-laying mechanism of the red imported fire ant. Each time an egg is laid, the vulva opens and the sting is fully extended. When the vulva closes, the egg is forced to the base of the sting, whereupon the sting is usually retracted across the egg. This phenomenon has been consistently observed for queens from single queen and multiple queen fire ant colonies. Zero to 4 eggs can be laid for each vulva opening. Multiple egg deposition is more frequent for queens from single queen colonies, and it generally follows an oviposition cycle in which no egg is laid. The egg-laying cycles were evenly distributed during the observation periods, regardless of the total number of eggs laid. This suggests that oviposition is a continuous process in the red imported fire ant. This research has implications in the areas of hymenopteran evolution, caste determination, as well as queen control of colony sociality.

Technical Abstract: The oviposition process of Solenopsis invicta is described as a succession of four events forming one egg-laying cycle. Each time an egg is laid, the vulva opens and the sting is fully extended. When the vulva closes, the egg is forced to the base of the sting, whereupon the sting is usually retracted across the egg. This phenomenon has been consistently observed for queens from monogynous and polygynous S. invicta colonies. Zero to 4 eggs can be laid for each opening of the vulva. Multiple egg deposition is more frequent for monogyne queens, and it generally follows an oviposition cycle in which no egg is laid. The egg-laying cycles were evenly distributed during the observation periods, regardless of the total number of eggs laid. This suggests that oviposition is a continuous process in S. invicta. This is the first detailed description of the sting's involvement in egg deposition. This research has implications in the areas of hymenopteran evolution, caste determination, as well as queen control of colony sociality.