Search

The hematophagous bug Triatoma brasiliensis (Neiva) is an important vector of Chagas disease in Brazil. We describe the mating behavior of this species in a comparative manner and analyze the effect of time elapsed since the first imaginal bloodmeal on motivation of males to mate, on female mate-rejections, and on overall mating frequency. We also evaluate whether females of this species copulate with several males in short time intervals, and we examine whether the duration of copulation may vary in the presence of other males compared with what is observed with isolated pairs. Age affected the motivation of males to perform mating attempts, whereas nutritional status affected the receptivity of females. Results showed that 70% of the females tested accepted copulating with three males over a period of 90 min, whereas the remaining 30% mated with at least two males. Mating duration in T. brasiliensis was prolonged in the presence of other males compared with observations of isolated pairs, and males of this species performed long postcopulatory associations only in the presence of other males, apparently as a mate guarding response to the presence of potential competitors.

The thermopreference of resting P. megistus (Burmeister, 1834) adults was studied in a temperature gradient. We also determined the thermopreference for oviposition and ecdysis. Thermopreference of resting individuals depended on the feeding state of the insects. Results demonstrated an initial resting preference of ≈29°C, which gradually changed to 26–27°C with increasing starvation. A daily variation in thermopreference was also observed with this species. The insects showed a daily maximum preference at the beginning of the dark phase, and a minimum preference during the first half of the light phase. Ecdysis took place all along the gradient, but exhibited a maximum frequency at 30°C. Most eggs were found between 25 and 29°C. Results are discussed in relation to the ecology of P. megistus as compared with other related species, and the existence of mechanisms of behavioral thermoregulation in the group.

The hematophagous bug Triatoma brasiliensis (Neiva) is an important vector of Chagas disease in Brazil. We describe the mating behavior of this species in a comparative manner and analyze the effect of time elapsed since the first imaginal bloodmeal on motivation of males to mate, on female mate-rejections, and on overall mating frequency. We also evaluate whether females of this species copulate with several males in short time intervals, and we examine whether the duration of copulation may vary in the presence of other males compared with what is observed with isolated pairs. Age affected the motivation of males to perform mating attempts, whereas nutritional status affected the receptivity of females. Results showed that 70% of the females tested accepted copulating with three males over a period of 90 min, whereas the remaining 30% mated with at least two males. Mating duration in T. brasiliensis was prolonged in the presence of other males compared with observations of isolated pairs, and males of this species performed long postcopulatory associations only in the presence of other males, apparently as a mate guarding response to the presence of potential competitors.