Preliminary work on the biology of Acerophagus texanus (Hymenoptera, Encyrtidae) and its potential as a biological control agent of Rhodesgrass mealybug (Hemiptera, Pseudococcidae)

Acerophagus texanus (Howard) is native to Texas and Mexico and has been reared from Rhodesgrass mealybug (Antonina graminis), an invasive pest species found on a wide range of grass species. The collection of A. texanus from multiple locations and the relatively high percentage of mealybugs parasitized by it have led to further investigations into its biology and biological control potential of this parasitoid. Rhodesgrass mealybugs are found on nodes above ground, as well as 2-3cm below the soil surface. Work was done to determine the preferred host location and size of mealybugs parasitized by A. texanus. The host species, Rhodesgrass mealybug, and Solenopsis invicta Buren have formed a mutualism where the mealybugs provide carbohydrates and in return receive protection from the fire ants. In order for any biological control agent of Rhodesgrass mealybug to function effectively, it must be able to parasitize hosts and successfully emerge in the presence of fire ants. A previous study showed that fire ants would remove and destroy the pupa of another parasitoid species, Neodusmetia sangwani, and was able to suppress the parasitoid population. Greenhouse experiments were run to determine if S. invicta had similar interactions with A. texanus.