Invasive Argentine ants are defending other pests in California, troubling farmers and leaving natives hungry

An invasive species of ants travelled across continents to America and is now defending other insects. According to a report by econews, Argentine Ants have been protecting aphids, mealybugs, scales, whiteflies and psyllids against the predators and parasites that would normally keep their population under control. This unlikely alliance has turned the ants into a hidden and looming problem for citrus groves, vineyards, nurseries and backyard plants.A century-old invasionArgentine ants are native to South America and were first detected in the United States around New Orleans in 1891. California recorded their presence by 1907 and researchers found that human transport created long-distance jumps far faster than the ants could spread by slowly budding into neighbouring nests.Their presence was only facilitated by California's mild coastal conditions. Irrigated farms, landscaped suburbs, leaky pipes and regularly watered gardens provide the moisture and steady food sources that allow colonies to persist in places where the surrounding landscape may otherwise be too dry.In their native range, neighbouring colonies of ants often fight. But in California, a genetic bottleneck reduced v...