Aleyrodids are found on the aerial parts of a wide range of terrestrial plants. They often inhabit
the underside of leaves, but sometimes can be found on the upper leaf surface. Whiteflies have
six life stages: egg, crawler (1st instar), two sessile nymphal instars (2nd and 3rd instars), the pupa
(4th instar) and adult. Identification of aleyrodids is largely based upon characters found in the
pupal (4th instar) stage.

Collecting Whiteflies
A hand-lens is useful when searching for and collecting whiteflies in the field.  Collect leaves
infested with whiteflies, wrap them in a paper towel to avoid excess humidity and subsequent
fungal growth, place the sample in a zip-lock plastic bag, maintain the sample refrigerated or in a
cooler until it is ready for slide-mounting. Identify the host plant or collect a sample of the plant
sufficient for identification by an expert.

In the Laboratory
Examine the infested leaves under the microscope and select the largest nymphs for specimen
preparation. Place a few drops of 10% potassium hydroxide (KOH) in a small vial. Scrape off
several of the largest nymphs from the leaf surface and place them into the vial. Sometimes it is
helpful to place a drop of KOH on the whitefly pupa to help loosen it from the leaf surface.
Allow them to soak in KOH overnight. The process can be expedited by heating the specimens
on low-heat on a hot plate for 10-20 minutes; however, the specimens are more likely to be
damaged, especially if all of the KOH evaporates, and the specimens are left on the hot plate.

Slide Mounting in Canada Balsam

• 1. Pour the specimens out of the vial into a small petri dish. If the specimens are very dark brown or black, clear them in bleach for several minutes.
• 2. Gently press on the top of the whitefly pupa with a small spatula or similar tool to extract the internal contents of the whitefly.
• 3. Place the pupae in stain for about 2 minutes.
• 4. Transfer specimens to 70-75% ethanol for 2-3 minutes. Do not use isopropyl alcohol in this process.
• 5. Remove the excess stain from each pupa by gently pumping the upper surface.
• 6. Transfer specimens to 95% ethanol for 2-3 minutes.
• 7. Submerge the pupae in clove oil for several minutes. When the specimen is first placed in the clove oil, its surface will shine as the clove oil replaces the alcohol in and on the specimen. The specimen is ready for slide mounting when it loses its shine.
• 8. Place a small drop (about 3/4 the diameter of the cover slip) of Canada Balsam at the center of a clean microscope slide. Dilute the balsam with a drop of xylene, if necessary.
• 9. Transfer the specimen from the clove oil and place it in the drop of Canada Balsam. The specimen should be positioned so that it is facing upward (the operculum is on the upper surface) and the head of the specimen faces towards you.
• 10. Place a coverslip on top of the specimen, apply gentle pressure to the top of the coverslip until the balsam extends to the edge of the coverslip.
• 11. Label the slide with the following data: Locality (Country, State, City, other), date of collection, collector and host plant, sample number, mounting medium (Balsam). For example, the label on the left is the species identification and the label on  the right is the collection data: