The red imported fire ant (Solenopsis invicta) may disrupt biological control of hibiscus mealybug (Nipaecoccus viridis) in Florida citrus. Controlling S. invicta may therefore be necessary for effective management of hibiscus mealybug. We evaluated four different methods to control S. invicta (ground applications of insecticide, two different insecticidal ant baits, and spot treating ant colonies with hot water) to determine how these different treatments affected ants tending to hibiscus mealybug colonies, natural enemy abundance within hibiscus mealybug colonies, and hibiscus mealybug colony abundance. While all treatments reduced the number of S. invicta colonies in treated areas compared to an untreated control, only ground applications of insecticide and the two ant baits significantly reduced the abundance of S. invicta found tending hibiscus mealybug colonies. Additionally, significantly more Brachymyrmex obscurior ants were found tending mealybug colonies in plots treated with either of the two ant baits. There was no significant effect of treatment on the abundance of natural enemies in hibiscus mealybug colonies, but significantly fewer natural enemies were found in mealybug colonies tended by S. invicta, and significantly more natural enemies were found in mealybug colonies tended by B. obscurior. Ground applications of insecticide, the abamectin ant bait Clinch and hot water treatments all reduced the overall number of hibiscus mealybug colonies compared to control areas, while the S-methoprene ant bait Extinguish did not. Our results suggest that reducing the number of S. invicta tending hibiscus mealybug colonies can lead to higher natural enemy abundance and lower hibiscus mealybug abundance. However, methods used to control S. invicta may have different impacts on ant species like B. obscurior, leading to different outcomes with natural enemies.

Data were collected in a 26-acre commercial Valencia orange grove in Lake Wales Florida USA (27°50'34.55"N, 81°34'29.99"W). Plots were laid out in a Randomized Complete Block Design, with five treatments and six blocks. Five treatments were assessed: 1) An untreated control; 2) Ground applications of insecticide consisting of chlorpyrifos and later, bifenthrin at a rate of 1 qt/acre for chlorpyrifos, and ~22.5 oz/acre for Bifenthrin; 3) An abamectin ant bait (Clinch) at a rate of 1 lb/acre; 4) An S-methoprene ant bait (Extinguish) at a rate of 1 lb/acre; and 5). Hot water applications to individual ant mounds.

Sampling took place between March 2021 and March 2022. Natural enemies and foraging ants were sampled by collecting mealybug clusters from the grove. S. invicta colonies were sampled by counting individaul colonies in the grove. Mealybugs were sampled by visually counting colonies.

Data were recorded in excel with minimal additional processing. More specific information is included in individual excel files.

Data were recorded in Excel.