LIPID CONSUMPTION IN IXODES-RICINUS (ACARI, IXODIDAE) - TEMPERATURE AND POTENTIAL LONGEVITY

The effect of temperature on the rate of consumption of the lipid rese rves in Ixodes ricinus Linnaeus was characterized in constant temperat ure experiments. There was a consistent linear relationship between te mperature and lipid consumption in nymphs and adult females and males between 5 and 37 degrees C. Nymphs and adults were able to withstand e xtended periods of exposure to temperatures within the range of 2-37 d egrees C, although at 2 degrees C there was evidence of thermal stress . The variance about the median rate of lipid consumption was found to increase with increasing rate of lipid consumption. Predictions of lo ngevity were made using the rates of lipid consumption for the three s tages studied, which ranged from 16 weeks to more than two years depen ding on temperature and stage. The predictions were consistent with re ported survival times for I. ricinus and followed patterns reported fo r other ixodid ticks.