| Abstrakt: |
Abstract: Observations on the blowfly Calliphora vicina Robineau-Desvoidy, 1830 under quasi-natural conditions in the environs of St. Petersburg (Russia) where the average temperatures ranged from 10 to 25 °C revealed that the correlation between the rate of its larval development and the mean daily temperature could be approximated by a linear regression (R=0.89). Laboratory experiments conducted under constant temperatures of from 12 to 23 °C also yielded a strong (R=0.93) linear correlation. The parameters for the development from egg to puparium calculated based on the data recorded in the field and laboratory (low temperature thresholds of 1.1±0.7 and 2.4±1.5 °C, regression coefficients 0.55±0.02 and 0.61±0.05, respectively) were not significantly different. The sums of effective temperatures were also practically the same: 193 and 188 degree-days for field and laboratory conditions, respectively. Further increase in the constant temperature up to 25-28 °C did not result in an increase in the rate of larval development in the laboratory and was similar to the developmental rate recorded under natural conditions at mean temperatures of 24-25 °C, but were slightly lower than the regression line. The rate of larval development when subjected to an artificial thermorhythm (temperatures alternating between 22 and 28 °C every 12 hours) was not significantly different from that recorded at a constant temperature of 25 °C. We conclude that the rate of larval development of C. vicina under natural thermorhythms can be reliably predicted based on parameters determined in the laboratory at constant temperatures. |
