Similar stocking and treatment procedures were used in 
temperature-delayed feeding-growth experiments. Food was withheld from one 
group at each temperature, and one group at each temperature was given food 
at the beginning of the experimental period. Initial dry weight measurements 
were made on a sample of 20 larvae at the beginning of the experiment. At the 
time each group was given its first food, a sample of 10 larvae from the unfed 
lot was weighed. At the end of the observation period all of the larvae in each 
treatment were measured and weighed. In cases where an intermediate growth 
observation was made between the time of first feeding, and before the end of 
the experiment, a sample of 10 larvae was used to establish growth of the 
population to this point. 
RESULTS 
Figure 16-1 shows the effect of delayed initial feeding on groups of larvae 
maintained at four temperatures. The survival time of the unfed control 
decreased with increasing temperature. The time to 50 percent mortality for 
unfed groups was 19, 21, 25 and 27 days after hatching among groups 
maintained at 24, 21, 18 and 15°C, respectively. Survival among early fed 
groups was generally highest in each temperature treatment. Among groups in 
which food was provided for the first time after up to 50 percent of the 
population had died, a portion of those remaining alive survived through the 
end of the observation period. A “point-of-no-return” beyond which survival 
could not occur even when food was provided, was nowhere in evidence in 
these experiments. In each temperature treatment the longer food was 
withheld, the greater the total mortality each group suffered. In cases where 
some additional mortality was observed after food was presented, there was 
generally evidence that the dead larvae had captured at least some food before 
expiring. 
Figure 16-2 shows the result of an experiment in which initial feeding was 
progressively delayed in a series of experimental groups of larvae held at five 
test temperatures. Changes in dry weight were used here to measure the rate of 
growth or shrinkage in fed and unfed groups at each temperature. Among 
starved lots, longevity increased and the rate of weight loss decreased at lower 
temperatures. Growth in dry weight increased rapidly once food was provided. 
In general, the effect of delayed initial feeding was to defer the attainment of a 
temperature-specific rate of growth of which larvae fed to satiation were 
capable. 
Larvae receiving their first food at day six after hatching at 15°C, had 
scarcely recovered their initial weight at hatching by the end of the 25-day 
observation period. Other groups which received their first food at day six after 
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