Do additional sugar sources affect the degree of attendance of Dysmicoccus brevipes by the fire ant Solenopsis geminata?

Abstract

Mutualistic interactions between ants and Hemiptera are mediated to a large extent by the amount and quality of sugar‐rich honeydew produced. Throughout the neotropics, the predaceous fire ant Solenopsis geminata (Fabricius) (Hymenoptera: Formicidae) is found in association with colonies of the pineapple mealybug, Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae), which they actively tend and protect from attack by natural enemies. In this study, we evaluate the effects of access to a sucrose solution on the mutualistic association between S. geminata and D. brevipes. Ten colonies of either species were established, with D. brevipes maintained on pumpkin, Cucurbita maxima Duchesne (Cucurbitaceae), in screen cages. Five of the S. geminata colonies were permitted access to vials with 20% sucrose solution and a pumpkin with 20 adult mealybugs. The remaining ant colonies were allowed access to mealybug‐infested pumpkins. Ant colonies with access to the sucrose solution attended mealybugs significantly less than those without additional sugar sources. Mealybug survival rates were similar under both treatments. Total body sugars and fructose were nearly twice as high in ants with access to honeydew and sucrose vs. those with access to honeydew and water. Fructose accumulated on the pumpkins over time in both treatments, suggesting that honeydew was not fully exploited by the ants. In conclusion, D. brevipes enjoy lower degrees of ant attendance when S. geminata have alternative sources of carbohydrates. We further discuss the significance of these findings for the conservation of predaceous ants and mealybug biological control.

Association between ants (Hymenoptera: Formicidae) and the vine mealybug (Hemiptera: Pseudococcidae) in table‐grape vineyards in Eastern Spain

“…Our results suggest that the provisioning of artificial sugars impacted ant activity, depending on the ant species, and helped reduce the mealybug population density dramatically. These results in combination with those of other studies by Carabalí‐Banguero et al, Nagy et al and Wäckers et al indicate that this method can be a simple, sustainable and effective alternative for managing honeydew‐producing pests by disrupting their mutualism with ants.…”

“…Another additional mechanism could be the increased predation on the mealybugs when their needs for sugar were satisfied. Feeding with sucrose reduced the attendance of the predaceous fire ant Solenopsis geminata (Fabricius) on the pineapple mealybug, Dysmicoccus brevipes (Cockerell) . Similarly, other studies have shown that predation by ants on aphids increases when excess alternative sugar sources are available …”

“…did not show a significant impact on entomophagous insects in vineyards . Crucially, depending on the sugar and protein availability and the nutritional requirements of the ant colony, ants may also prey on the mealybugs …”

“…In other systems, alternative strategies have been developed to alter the mutualistic association between ants and honeydew producers. Some of these methodologies involve the provisioning of alternative sugar sources, such as nectar from cover crops or artificial sugar …”

Mutualistic and antagonistic trophic interactions in canola: The role of aphids in shaping pest and predator populations

“…2). Ants often optimize aphid populations as both a source of sugar through the excreted honeydew (Mitter, 1958;Carroll and Janzen, 1973;Tschinkel, 2006;Lundgren, 2009;Lach et al, 2010;Yao, 2014), and food when prey becomes scarce (Way, 1954;Pontin, 1958;Cushman, 1991;Carabali-Banguero et al, 2013). Ant and predator densities were highest early on in the season when more food available in the form of aphids and the excreted honeydew.…”