LIBRARY

HEMIPTERA 343
species have been described. In Australia and New Zealand eight families are
represented, and the group probably attains its greatest development there.
For the most part the members of this superfamily are to be considered injurious
because of their great numbers and their damage to native and cultivated
plants. A number of species, however, have produced or still produce
articles of great commercial value that add greatly to the wealth of certain
countries.
Collecting and Mounting.
Scale insects occur abundantly in all regions where there are forests and
shrubbery and have become generally well established in orchards and ornamental
plantings. Therefore they are not difficult to find. They may be collected
in pasteboard boxes, bags, and in liquid preservatives and kept in many
different ways. A common method is to dry the specimens t'n situ on portions
of the bark, twigs, leaves, roots, or fruit of the host and file or mount these in
suitable small boxes. glass vials. riker mounts, or in opaque or transparent
envelopes together with necessary data, including the common and scientific
names, host, locality, date of collecting, name of collector, and name of determiner.
The soft mealybugs and other unarmored forms may also be indefinitely
preserved in alcohol.
For study and permanent preservation, scale insects should be mounted on
glass microscopic slides. Many methods may be employed in the preparation
of such mounts, those given here being simple and easy to master. The procedure
may be summarized as follows:
1. Remove the bodies of the males and females from the host and from the
protecting scales where present.
2. Wet and dissolve the waxy covering in alcohol, xylol, or other solvent.
3. Transfer to a 10 per cent solution of KOH to remove body contents.
Specimens may be boiled a few minutes in a test tube over a small
flame or placed in small vials or covered dishes in a warming oven at
lOO°F for 24 to 48 hours.
4. Body contents, especially eggs and embryos, should then be removed by
puncturing the wall and teasing them out with a flattened needle point
bent to a 35-degree angle, thus leaving a complete and perfectly clear
and clean skin.
5. Transfer to glacial acetic acid, remove all adhering particles, and press
out any KOH. For large specimens it is desirable to change the acid at
least once.
6. Specimens may be stained with any reliable stains, such as acid fuchsin
or magenta red or fast green. The time required depends upon the concentration
of the staining medium. Ordinarily the stain may be added
to the acetic acid in step 5. It is advisable to mount a few cleared specimens
along with the stained ones to show pigmentation.
7. Destaining or washing out the surplus dye may be accomplished by teasing
or by heating in a fresh supply of acetic acid for a few minutes.