Temporal and Spatial Patterns of Mating in Rhodnius prolixus

Area of Science:

• Entomology
• Chronobiology
• Animal Behavior

Background:

• The kissing bug, Rhodnius prolixus, is a nocturnal insect, but its mating timing and behavior are not well understood.
• Copulation in Rhodnius prolixus is lengthy (approx. 50 minutes) and involves minimal movement, suggesting a need for protection.

Purpose of the Study:

• To investigate the temporal and spatial patterns of Rhodnius prolixus mating.
• To determine if mating behavior is regulated by an endogenous circadian rhythm.
• To assess the role of shelters in mating behavior to reduce vulnerability.

Main Methods:

• Video recording of Rhodnius prolixus pairs over ten days in arenas with shelters.
• Observation under three lighting conditions: light:dark (L/D), constant light (L/L), and constant darkness (D/D).
• Analysis of copulation timing, duration, and location (shelter vs. open arena).

Main Results:

• Rhodnius prolixus pairs predominantly mated during daylight hours under L/D cycles.
• This mating rhythm persisted under constant darkness (D/D), indicating endogenous control.
• Mating occurred more frequently within shelters under L/D and L/L conditions, but was random in D/D.

Conclusions:

• Rhodnius prolixus possesses an endogenously controlled circadian rhythm influencing mating behavior.
• Mating activity is primarily concentrated during the subjective daylight hours.
• Shelters are utilized during mating, likely as a strategy to minimize predation risk.