Temperature effects on the non-parasitic phase of Amblyomma parvum (Acari: Ixodidae)

Abstract

The tick Amblyomma parvum has a wide distribution in the Central and South America. Therefore, throughout its distribution range, populations of this tick are exposed to different abiotic factors (e.g., Temperature and humidity). Here, we assess the effect of five temperatures, 18°C, 21°C, 24°C, 27°C, 32°C and 80 ± 10% RH on non-parasitic phases of A. parvum under controlled conditions of laboratory. Our results show that temperature affects all parameters of the non-parasitic phases of A. parvum. Mean periods of premolt and molting of immatures, and mean periods of pre-oviposition, oviposition and incubation of females decreases as temperature increases from 18 °C to at 32 °C. Conversely, the molting success of larvae increased from 18 °C to 32 °C but the percentages were statistically non-significant under 21°C, 24°C and 27°C. The molting success of nymphs was higher than 95% under all temperatures. Mean percentages of egg mass and EPE increases as temperature increase from 18 °C to 27°C, then both decrease at 32 °C. The mean percentage of egg hatching was higher than 90% from 21 to 32 °C. The total non-parasitic phase of A. parvum was completed in an average of 223.4, 150.9, 114.7, 90.2 and 69.0 days, respectively, under temperatures of 18°C, 21°C, 24°C, 27°C and 32°C. The effect of five temperatures studied in this experiment suggest that populations of A.parvum can exhibit different biological and ecological behaviors throughout its distribution range, as expected to occur in ticks with wide range distribution.