The effect of long and short-distance lures in the attraction of the blood-sucking bugs Triatoma dimidiata and Rhodnius prolixus (Hemiptera: Reduviidae)

To develop a technology for controlling triatomine bugs, the vectors of Chagas disease, the behavioral responses of two species of kissing bugs, Triatoma dimidiata (5th instar nymphs) and Rhodnius prolixus(5th instar nymphs and adult males), to different known or suspected attractants, alone or in combination, were investigated. Tests were done using a four-port olfactometer, computer-assisted video tracking system,and a 1.3 M x 0.9 M high artificial chamber that mimicked the bug’s natural habitats. Heat was found to be attractive as opposed to selected chemicals (e.g., 1-octen-3-ol, isobutyric acid, etc). Different combinations of odorants administered as lures, attracted all three bug types, but there was a significant increase in attraction when heat was added, or when heat + CO₂ was added. A significantly greater attraction was observed with the nymphs of both species versus adult male R. prolixus. The artificial chamber studies revealed a synergistic effect when lure types were combined. Chemical analysis (gas chromatography) indicated that 1-octen-3-ol was emitted from the chemical lures in amounts ranging from as little as 6.7 ng in 5 minutes to as much as 106.4 ng within 30 minutes. Using a solid phase micro extraction (SPME) device to collect the odorant, it was found that this compound could be detected as far as 86 cm from the emitting source. These findings suggest that a chemical lure combined with a heating element, CO₂ and a suitable insecticide or trap can serve as a targeted attract and kill device to control triatomine bugs in the field.