【Background】Mutually beneficial relationship between invasive organism can enhance the spread of both species. The red imported fire ants Solenopsis invicta Buren workers tend colonies of the cotton mealybugs Phenacoccus solenopsis Tinsley. This relationship may be mutually beneficial: it can increase the food supply of ants, and ants may protect the mealybug colonies, or even assist their spread. 【Method】We performed manipulative experiments, by planting hibiscus plants in a cruciform arrangement, and inoculated the plants with the cotton mealybug. By appropriately placing fire ant colonies at various distances, we observed and recorded the effect of the fire ant invasion on the cotton mealybug short-range spread. 【Result】With increasing distance from the nest, the number of fire ant workers on hibiscus reduced gradually. The rates of hibiscus infected by mealybugs were 75% and 45% at 2 m and 3 m distances from the fire ant nests, respectively. These were significantly higher than rates (25% and 10%) in areas with no fire ants. The infection rates for the hibiscus plants were significantly correlated with the number of the fire ants, and could be described by the equation: Infestation rate=0.0042X (no.of fire ants)+0.1992. 【Conclusion and significance】The results indicated that fire ant invasion facilitated the short range (2~3 m) dispersal of the cotton mealybugs, and provided the supporting data for indepth understanding the co-invasion of the fire ants and the cotton mealybug.