Specificity of the Red Imported Fire Ant Phagostimulant Response to Carbohydrates
The red imported fire ant, Solenopsis invicta Buren, is considered an oil-loving feeder, however, carbohydrates are essential ingredients in the diet of the fire ant also. Comprehensive screening of mono-, di-, and tri-saccharides demonstrated that glucose, fructose, fucose, sucrose, maltose, turanose and raffinose were significant phagostimulants for fire ant workers. It was also found that while D-glucose and L-fucose, the naturally occurring isomers, were active, the opposite diastereomers were not. Any structural modification of the glucose molecule resulted in loss of activity. None of the sugar alcohols evaluated were active. The fire ant is an agricultural pest and the many reports of fire ant damage to food crops may be linked to their need for dietary carbohydrates. A knowledge of carbohydrate phagostimulants may help to understand specificity of fire ant /plant interactions.
Red Imported Fire Ants: Feeding on Radiolabeled Citrus Trees
Navel orange and ruby red grapefruit trees made radioactive by soaking the rootsin a 32P solution were fed upon by workers of the red imported fire ant (RIFA). Solenopsis invicta Buren. Workers obtained radioactivity from all radiolabeled citrus trees; after 24 h, 53% of ants sampled were radioactive and ca. 80% were radioactive from day 2 through day 10. New leaves, blossoms, and small fruit were consumed by the ants. The availability of supplemental food (house fly pupae) did not reduce feeding on the citrus trees.
Feeding in the Larvae of the Imported Fire Ant, Solenopsis invicta: Behavior and Morphological Adaptations
Adult workers of the imported fire ant, Solenopsis invicta Buren, feed liquid foods, including sucrose and soybean oil, to larvae of all instars, and feed solid proteinaceous foods only to the 4th instars. Solid foods, including undamaged fire ant eggs, experimentally placed on larvae, are ingested only by 4th instars. Workers place solid food, of a specific size range, on the antero ventral region of 4th instars. This region bears specialized hairs and spines which hold solid food while the larvae feed on it. The relationship of larval feeding to a possible method of fire ant control is discussed.