Evidence of queen-rearing suppression by mature queens in the little fire ant, Wasmannia auropunctata

Authors: COLLIGNON, MAX - Eastern Mennonite University; SIDERHURST, MATTHEW - Eastern Mennonite University; Cha, Dong

Submitted to: Insectes Sociaux
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2023
Publication Date: 5/10/2023
Citation: Collignon, M.R., Siderhurst, M.S., Cha, D.H. 2023. Evidence of queen-rearing suppression by mature queens in the little fire ant, Wasmannia auropunctata. Insectes Sociaux. 70:259-263. https://doi.org/10.1007/s00040-023-00917-4.
DOI: https://doi.org/10.1007/s00040-023-00917-4

Interpretive Summary: Little fire ant (LFA) is one of world’s most aggressive and destructive invasive pests with huge economic, environmental, and health impacts. Once established in a new area, it is extremely difficult and costly to eradicate LFA. A queen pheromone of ants could offer a means to shutdown LFA reproductive capability, potentially by suppressing production of new queens or inducing execution of queens or queen-destined larvae. To develop an environmentally-friendly eradication tool, researchers at USDA-ARS laboratory in Hawaii and Eastern Mennonite University are identifying queen pheromone for LFA. As a first step, this study demonstrated the effect of queen presence on LAF queen production. When queenless experimental nests and multi-queen experimental nests were compared, queenless nests successfully reared new alate queens and drones to adulthood, while no adult alate queens or drones were reared out from multi-queen nests. This is the first evidence of LFA queen pheromone and suggests that the queen pheromone may be applicable to suppress the LFA population.

Technical Abstract: Little fire ant (LFA), Wasmannia auropunctata, is a serious invasive pest first reported on Hawaii Island in 1999, and has since spread and established itself across the island. LFA is considered one of the worst 100 invasive species, and has significant ecological, agricultural, and public health impacts in invaded areas, which include much of the tropical New World. Although localized eradication efforts have proven successful, they are intensive and difficult to implement. Furthermore, LFA’s high invasive-ability mollify these control efforts in areas where the species is established and can re-infest treated areas. To develop environmentally-friendly management tools for established populations of LFA, this research set out to determine whether LFA queens have a suppressant effect on new queen production in nests, as a first step in identifying a potential queen pheromone for LFA. A queen pheromone could offer a means to shutdown LFA reproductive capability, potentially by suppressing production of new queens or inducing execution of queens or queen-destined larvae. When queenless experimental nests and polygyne experimental nests were compared, 6 out of 8 queenless nests successfully reared both new alate queens (2.25 queens/nest) and drones (3.63 drones/nest) to adulthood, whereas only 3 of 8 polygyne nests reared some sexual larvae that failed to develop to adulthood or even the pupal stage. These results suggest that dealate mature LFA queens have a suppressant effect on production of new alate queens in LFA nests, and is the first evidence that LFA may utilize a queen pheromone.