In late spring, in summer, and in early fall, insects are very abundant
in fields and woods, and large numbers of them may be caught by sweeping
through the grass and branches with a strong insect net. Flowers of all
descriptions are favorite visiting places of many bees, flies, beetles,
and other insects, and will afford good collecting. Woods along the
banks of streams, open glades in deep woods, and brush along forest
edges offer some of the best opportunities for collecting by the
sweeping method.
In early spring, when insects can be taken only sparingly in the open,
the collector frequently finds sheltered hollows where they may be
caught in large numbers. A certain kind of insect may live only on a
certain kind of plant, and to obtain the insect the collector must
search or sweep the plant, called the host plant.
Many obscure places harbor insects seldom found elsewhere. Among these
are leaf mold and debris on the surface of the soil, particularly in
woods; rotten logs and stumps, which should be turned over to reveal
insects that hide under or around them, and then carefully searched or
torn apart for others that live inside; in, under, and around dead
animals; under boards and stones.
Trees sometimes yield valuable specimens. If part of a tree, under which
has been spread a large white sheet, is struck with a heavy, padded
stick, many insects, such as weevils, will fall to the sheet and "play
possum." They can be picked off quite easily.
Lights attract large numbers of certain nocturnal insects, such as June
beetles and many kinds of moths; at night these insects may be collected
at street or porch lights, on windows and screens of lighted rooms, or
at light traps put up especially to attract them. Swarms of aquatic
insects come to street lights of towns along rivers, sometimes in such
numbers as to pile up in a crawling mass under each light. Collecting at
this source is best on warm, cloudy nights; wind or cold keeps most
nocturnal insects fairly inactive. Different species of moths and
beetles visit the lights in different seasons so that collecting by this
method alone yields many kinds of insects.
Insects that live in the water may be collected with heavy dip nets
swept through the water at various levels and through the mud and debris
at the bottom. In shallow water, many insects will be found if stones
and logs are turned over and leaf tufts pulled apart.
In winter, insect galls or cocoons may be gathered. If these are placed
in jars with cheesecloth covers tied over them, kept in a warm room, but
away from radiators and all intense heat, many insects will emerge from
them before spring.