2.4. Experiments with larvae
Larvae chosen for irradiation were of three different
ages: 1–9, 9–18 and 18–27 days old plus the control. Using
soft forceps, larvae of similar age were isolated into four
different groups, one for the control and three for the
different doses. Each group consisted of three replicates,
with 20 insects/replicate. Larvae in each replicate were
exposed simultaneously to the designated UVC dose by
placing these larvae in a plastic screw cap. Each treatment
group was exposed to one of three doses of UVC,
namely, 56.52 J cm2 (exposure time 3 min), 150.72 J cm2
(exposure time 8 min), and 226.08 J cm2 (exposure
time 12 min). After exposure to UVC, irradiated larvae
were returned to their corresponding Petri dish and
provided with wheat and cracked wheat grain as food.
All irradiated and control larvae were returned to the
incubator under the conditions described in Section 2.1.
Development of larvae was followed until the end of their
life cycle. Time between selecting and grouping the larvae
and returning them to the incubator after irradiation was
never more than 2 h.