Маленькие огненные муравьи захватили Гавайи: от 13 очагов до 4000 зараженных мест за 15 лет

Back in the 1990s, a tiny orange ant probably hitched a ride into Hawaii inside a shipment of potted plants, and nobody realised what had arrived until years later. According to Donna Lee and colleagues in Ecological Economics , the ants most likely arrived in a shipment of potted plants from Florida. The plants were sold to consumers along Hawaii Island's east coast, carrying little fire ant colonies in their potting medium. When the infestation was discovered in 1999, the ants were already present at 13 locations. The researchers later documented more than 4,000 infested locations on Hawaii Island, 15 years after the initial detection, while isolated infestations had also been recorded on Kauai, Maui and Oahu. These figures describe the period examined in the study and should not be taken as a measure of the invasion's extent in 2026. What the historical record does show is how quickly an introduction that was initially difficult to detect expanded across the island. The ant's small size makes an early infestation easy to overlook, but an established population can reach remarkable densities. In a 2008 field study published in the Journal of Economic Entomology , Evann Souza and colleagues examined little fire ants in a tropical fruit orchard growing rambutan and mangosteen. Using shallow core samples from the orchard floor, the researchers estimated an absolute density of more than 244 million ants per hectare, equivalent to 22.7 kilograms of wet ant biomass per hectare. They described the population as a supercolony. The measurement came from this particular orchard, so it provides evidence of how dense an established population can become rather than a population estimate for Hawaii's farms as a whole. Human activity provided another pathway for the ants to occupy new areas. Lee and colleagues recorded infestations across agricultural, nursery and residential settings, as well as parks and schools. Their analysis also identified the movement of infested soil, produce and other materials as ways colonies could be unintentionally transported. Nursery plants were especially important because they could both harbour colonies and carry them to new locations. As a result, the invasion did not have to progress solely through neighbouring habitats. A colony hidden in material being moved between properties could establish a new population elsewhere. How the ants became a problem for farms and homes Agriculture became an important part of the invasion story. In the 2008 Journal of Economic Entomology study, Souza and his co-authors tested three control products, Amdro, Esteem and Conserve, in an infested rambutan and mangosteen orchard. Treatments were applied every two weeks for 16 weeks, while relative ant abundance was monitored through transect sampling with peanut butter-baited sticks. By weeks 13 to 17, ant numbers were 47.1% lower than pretreatment levels in the Amdro plots and 92.5% lower in the Esteem plots. Counts in untreated plots, by comparison, were 185.9% higher. Conserve did not produce a significant reduction under the conditions of the trial, and none of the treatments eliminated the infestation. The researchers also found ants nesting in protected sites in the orchard trees, which could affect how effectively treatments reached them. The experiment therefore demonstrated suppression rather than eradication. Its findings came from one orchard and one field trial, but they illustrate the practical difficulty of reducing an established population when colonies are spread through vegetation and are not all equally exposed to treatment. The effects also reached people living and working in infested areas. Lee and colleagues describe painful stings in homes, schools, lodging facilities, parks and other human environments. The sting can cause an intense burning sensation followed by painful, itchy welts, although reactions vary between individuals. The study also incorporated human and pet sting incidents into its economic analysis, showing that the consequences of an infestation were not limited to the cost of treating the ants. Nurseries faced an additional problem because plants could serve as both habitat and transport. The Ecological Economics analysis associates infestations with lost productivity, treatment expenses and reduced consumer demand for infested plants. Lee and colleagues also used economic modelling to examine how different levels of management could affect future costs. Their analysis suggested that greater investment in detection, prevention and treatment could reduce the longer-term economic burden under the scenarios they examined. These were modelled outcomes rather than observed losses, so they should be understood as estimates of possible consequences rather than predictions of what has happened since the study period. These ants not only deliver painful stings but also wreak havoc on agriculture and native ecosystems. While some control methods have been moderately effective, complete elimination remains elusive, exacerbated by ongoing human transport facilitating their invasion. Image Credits: Wikimedia Commons The problem was not confined to agriculture and residential areas. Lee and colleagues describe little fire ants as a threat to native biodiversity and tropical ecosystems, noting that the species can sting reptiles and birds and interfere with reproduction, nesting and the survival of young. The paper also discusses effects on domestic animals. These observations led the authors to consider the invasion in ecological as well as agricultural and economic terms. The same Ecological Economics study used a bioeconomic model to explore how the infestation could develop under different management strategies. Under the model's current-management scenario, infestations were projected to continue increasing across several sectors and eventually become established throughout developed locations on Hawaii Island within the modelled period. Greater management effort was projected to slow that expansion and reduce associated costs, while weaker control was projected to allow greater spread. Because these results were generated by a model under specified assumptions, they should not be presented as observations of Hawaii's situation today. The historical evidence nevertheless shows why the researchers regarded early intervention as important. The infestation went from 13 known locations when it was detected in 1999 to more than 4,000 locations during the period covered by the study. At the orchard scale, the 2008 field experiment showed that even treatments that substantially reduced ant abundance did not eliminate an established population. Together, the findings illustrate two different parts of the problem: human movement could help colonies reach new places, while dense established populations could prove difficult to suppress once they were there. What began as a likely introduction hidden in potted plants during the 1990s had therefore developed into a substantial invasive-species problem by the time these studies were conducted. The research documents spread across thousands of locations on Hawaii Island, infestations in agricultural and residential settings, and a supercolony reaching an extraordinary density in one tropical fruit orchard. It also records concerns for native wildlife and costs associated with stings, treatment and affected businesses. The two studies do not establish how extensive the invasion is in 2026, but they provide a clear historical account of how a barely noticed introduction became a difficult management problem.