[Biological parameters of Meccus phyllosomus phyllosomus (Burmeister), 1835, Triatoma recurva (Stål), 1868 (Hemiptera, Reduviidae) and their laboratory hybrids].

Introduction: Hybrids from species and subspecies of Mexican triatomines have shown outstanding biological and behavioral characteristics as compared with their parental groups. This could lead to an increasing risk of transmission of Trypanosoma cruzi to human and animal reservoir hosts.

Objective: To describe and compare biological parameters related to the life cycle of Triatoma recurva, Meccus phyllosomus phyllosomus and their laboratory hybrids and estimate their risk as transmitters of T. cruzi to humans.

Materials And Methods: We kept a cohort of each one of the three groups (T. recurva, M. p. phyllosomus and their hybrids) under similar laboratory conditions and then compared them to record the data related to their life cycles, number of blood meals to molt, mortality rates, egg eclosion rates and female fecundity.

Results: The hybrid cohort showed the lowest mean time from first-instar nymph to adult (136.6 ± 17.5 days). The number of blood meals from molt to next instar (13.4 ± 1.7; 15.6 ± 5.2) was higher in the hybrid and T. recurva cohorts. The hybrid cohort showed the lowest mortality rate (29.5%) and the highest rate (70%) of adult females at the end of the biological cycle. Fecundity per day per female (range: 1.1 ± 0.6- 1.6 ± 0.7 eggs) was similar in the three cohorts. Egg hatching rate was higher than 70% in both hybrid and M. p. phyllosomus cohorts.

Conclusion: The hybrid cohort showed some outstanding biological characteristics, which would entail a higher risk of transmission of T. cruzi to hosts than their parentals.