Research Methods in Toxicology and Insecticide Resistance ...

Fig. 5.4. Preparation of test insects for topical application: (A) collection
of 10 female adult planthoppers (1 to 2 days old) to be placed in a vial
with a wire-mesh screen cap; (B) anaesthetization with CO 2 .
Fig. 5.5. Topical application: (A) anaesthetized planthoppers on watchglass wrapped with
gauze; (B) Hamilton Repeating Dispenser and microsyringe.
The treated insects are transferred in clear tumbler cages through a funnel with
the aid of a small camel-hair brush to minimize mechanical damage (Fig. 5.6). The
cages with treated insects are placed in a controlled room with a temperature range
of 25 to 30 °C and 12 hours of light.
After an insecticide treatment, either the gauze or the whole watchglass covered
with gauze is replaced to avoid contamination of new batches of test insects with the
previous insecticide.
56 K.L. Heong, K.H. Tan, C.P.F. Garcia, L.T. Fabellar, and Z. Lu