study thermal susceptibility characteristics of insects.
The heating system consists of two metal
blocks with heating pads capable of producing
from 0.2 to 28°C/min heating rates. An aluminium
plate with four square openings is sandwiched
between the two metal blocks to form
compartments, each capable of holding several
insects. The thickness of the sandwiched plates
can be adjusted for different insect size to ensure
direct contact between insects and metal blocks
during heating tests. With a solid state relay and a
data acquisition system, the block temperatures
can be controlled to increase to the desired set
point within 90.3°C at selected heating rates
(Fig. 1). The data acquisition software displays
the real time data to enable monitoring and confi-
rmation of treatment heating rate, set point temperature,
and holding time. An engineering
analysis of the heating block system shows that
for fifth instar codling moth (12–20 mm long and
2.0–2.5 mm wide), the temperature differential
(lag) between the block and the centre of insect
body was less than 0.2°C and 0.6°C at the 5°C/
min and 20°C/min heating rates, respectively, 30
seconds after reaching the selected holding temperature.
Detailed information on this system is