Temporal and Spatial Patterns of Mating in Rhodnius prolixus

Abstract

The kissing bug Rhodnius prolixus is a nocturnal species; however, its temporalmating patterns remain unexplored. Copulation lasts about fifty minutes, during whichtime the couple remains almost motionless. We hypothesized that R. prolixus copulateswithin shelters to reduce its vulnerability. To test this, we examined the spatial and temporalpatterns of its copulation, as well as the potential endogenous regulation of its circadianrhythm, under three conditions: a light:dark cycle (L/D), constant light (L/L), and constantdarkness (D/D). Over ten days, the number and the timing of copulation of pairs in arenascontaining a shelter were video-recorded. Under the L/D cycle, the pairs mated mainlyduring daylight hours. This rhythm persisted under the D/D cycle, with a peak extendingfrom the first half of the subjective day to the first half of the subjective night. No rhythmwas observed under the L/L cycle. A greater proportion of mating occurred within theshelters during the L/D and L/L cycles, whereas its spatial distribution was random underthe D/D cycle. Our results reveal an endogenously controlled circadian rhythm of matingbehavior, with mating activity mainly occurring during daylight hours. Additionally, weshowed that the pairs copulated inside the shelters. These results provide new insights intothe reproductive behavior of R. prolixus.