RESPIRATORY GAS-EXCHANGE IN THE TICK AMBLYOMMA-HEBRAEUM (ACARI, IXODIDAE)

Respiratory ps exchange was studied in unfed adult Amblyomma hebraeum Koch. Carbon dioxide emission was measured at 25-degrees-C using flow- through respirometry to determine standard metabolic rate and the temp oral pattern of gaseous emmission. The standard CO2 production rate (s V(CO2) of inactive ticks was 0.0135 +/- 0.0085 ml g-1 h-1, and the sta ndard O2 consumption rate (sV(O2) was 0.0158 +/- 0.0097 ml g-1 h-1. Ve ntilation was discontinuous and was characterized by periodic bursts o f CO2 emission at frequencies of 0.33 h-1-1.11 h-1. Low metabolic rate coupled with discontinuous ventilation may contribute to the ability of adult A. hebraeum to withstand prolonged periods of starvation and desiccation in the absence of a host