Resource Information

Slide Mounting Techniques  

Techniques for mealybugs and scales

1) While the insect is still in isopropyl alcohol puncture it behind its last leg with a needle or small scalpel.
2) Place the insect into a 10% potassium hydroxide solution (2 pellets of potassium hydroxide in 6 cc of water).
3) Gently pump and tease out the contents of the insect using a spatula. The shells of hard scales should be removed at this time.
4) Leave the insect in the solution at room temperature for 24 hours.
5) Transfer the insect into water to rinse off the potassium hydroxide.
6) Transfer the insect into 70% isopropyl alcohol to dehydrate.
7) Transfer the insect into 70% isopropyl alcohol with a drop of stain and leave for 30 minutes.
8) Transfer the insect to cellusolve for 5 minutes (skip if mounting in Hoyer’s).
9) Mount the insect ventral side up using Canada balsam or Hoyer’s.
10) Allow the slides to dry for 10 to 14 days on a slide warmer.
11) Periodically check for air pockets. Remove them by adding Canada balsam or Hoyer’s to the edge of the coverslip. Slight heat may be necessary to displace the air pockets.
11) Ring the edge of the coverslip with Glyptal electric paint (skip if mounting in Canada balsam). Two coats are needed to keep out moisture.
12) Scrape away excess Canada balsam or Hoyer’s that seeped out of the coverslip.

Whitefly pupae and light colored thrips: These may be mounted directly without clearing in potassium hydroxide. They are mounted dorsal side up. Staining is optional.
Dark colored aphids: These should be cleared in potassium hydroxide. They are mounted dorsal side up.
Thrips: As with aphids, dark thrips should be cleared in potassium hydroxide while light ones should not. They are also mounted dorsal side up.

I would like to thank Grace Nakahashi for explaining this technique.