Air Temperature Records as a Guide to the Date of Hatching of the Nymphs of Austroicetes cruciata, Sauss. (Orthoptera)

Abstract

Most of this paper is occupied with the description of a method for evaluating the influence ol temperature, recorded in the field, on the rate of development of the eggs of a grasshopper (Austroicetes cruciata). When the conventional methods of temperature summation were used, important errors were introduced because:—(a) The temperature in the environment of the insect may be different from the temperature in the meteorological screen.(b) The arithmetic mean of the maximum and minimum temperature may not be an adequate estimate of the true mean temperature for the day.(c) The relationship between temperature and the rate of development of the organism over the range of temperature used, was not linear.(d) Development may proceed for less than 24 hours of each day.