Insects need to be studied carefully to distinguish the
beneficial from the harmful. People have often gone to great trouble and expense
to destroy quantities of insects, only to learn later that the insect destroyed
was not only harmless but was actually engaged in saving their crops by eating
destructive insects. Most entomologists have had correspondents send in the
larvae of lady beetles with the complaint that they were injuring plants; at the
same time overlooking the smaller aphids which were causing the injury and which
these larvae were continually devouring.
Insects are beneficial to the gardener in several ways:
-
Insects aid in the production of fruits, seeds,
vegetables, and flowers, by pollinizing the blossoms. Most common fruits are
pollinized by insects. Melons, squash, and many other vegetables require
insects to carry their pollen before fruits set. Many ornamental plants,
both in the greenhouse and out of doors, are pollinated by insects for
example, chrysanthemums, iris, orchids, and yucca.
-
Parasitic insects destroy other injurious insects by living
on or in their bodies and their eggs. Insects also act as predators,
capturing and devouring other insects.
-
Insects destroy various weeds in the same ways that they
injure crop plants.
-
Insects improve the physical condition of the soil and
promote its fertility by burrowing throughout the surface layer. Also, the
dead bodies and droppings of the insects serve as fertilizer.
-
Insects perform a valuable service as scavengers by
devouring the bodies of dead animals and plants and by burying carcasses and
dung.
Many of the benefits from insects enumerated above, although
genuine, are insignificant compared with the good that insects do fighting among
themselves. There is no doubt that the greatest single factor in keeping
plant-feeding insects from overwhelming the rest of the world is that they are
fed upon by other insects. It is easy to see how the industry of insects and
their devotion to purpose, when coupled with almost unlimited numbers, can
benefit us when they seek and devour myriads of pests scattered over a farm or a
forest.
Of cause there are many harmful insects known as pest need to
be controlled and dealt with, pest alerts information can be found at
USDA Forest Service's Pest Alert Master List for the USA
National Agricultural Pest Information System (NAPIS) Index
University
of Illinois Extension Home & Garden Pest Newsletter
University of Kentucky Entomology Department Insect Pest Fact
Sheets
