e bottom of a pond and pile it on the bank. As the water soaks away
watch for signs of life in the mass. If you find a few small creatures,
say half an inch long with large head and eyes, broad body and with six
rather long legs they are probably the nymph stages of dragon-flies.
Wash the mud off of them so that you can examine them carefully. With a
straw probe in the mouth and you will find that the lower lip is a long
elbowed structure which can be suddenly thrown out in front of it and
with a pair of pincher-like prongs at the tip it can catch and hold its
prey. Some forms keep their bodies covered with mud so that they can
slowly creep up close to their prey.

Collect several nymphs and keep them in a jar of water and study their
movements and feeding habits. Disturb one with a pencil or straw and see
how it darts forward. It has a water chamber in the large intestines,
including also the respiratory tracheal gills, from which the water can
be suddenly squirted which throws the insect forward. The escaping
stream of water forces the insect forward on the same principle as the
rotating lawn sprinkler. If you collect some almost mature nymphs and
keep them for a time in a vessel of water you may see them crawl out of
the water, shed their skin and change to winged adults. Collect a few
adults of different species for pinning in your permanent collection.

CHAPTER XIV

THE SQUASH BUG

This common blackish or earth-colored bug is usually called the squash
stink-bug. It has a very disagreeable odor which gives it this name.
When disturbed it throws off from scent glands a small quantity of an
oily substance which produces this odor. This is a protection to it for
few birds or animals care to feed on it. Most species of sap or blood
sucking true bugs have a similar protecting odor.

The squash bug feeds largely on squash and pumpkins. It has a slender
beak with needle-like mouth parts which are stuck into the plant for
extracting the sap. It feeds only on plant sap. When it can not get
squash or pumpkins it will feed on watermelons, muskmelons and related
crops. It is very destructive to these crops. It not only extracts sap
thus weakening the plant but it also seems to poison the plant while
feeding. In this way its bite injures the plant something like the
effects of the bed-bug's bite on our flesh. It feeds first on the leaves
and vines often killing them in a few days. Later it may cluster and
feed on th