Acridids (grasshoppers and locusts) can range from being rare
curiosities to abundant menaces. Some are threatened with extinction and
become subjects of intensive conservation efforts, while others are
devastating pests and become the objects of massive control programmes.
Even within a species, there are times when the animal is so abundant
that its crushed masses cause the wheels of trains to skid (the Rocky
Mountain grasshopper, Melanoplus spretus Walsh in western North America
in the 1860s and I 870s), while at other times the animal is alarmingly
scarce (the Rocky Mountain grasshopper went extinct in the early 1900s).
Why are there these extremes in one insect family, and even in a single
species? The NATO workshop examined this paradox and its implications
for Environmental Security, which must address both the elements of land
use (agricultural production and pest management) and conservation of
biodiversity. The reconciliation of these objectives clearly demands a
critical assessment of current knowledge and policies, identification of
future research, and close working relationships among scientists.
Insects can present two clear faces, as well as the intervening
gradation. These extremes require us to respond in two ways:
conservation of scarce species and suppression of abundant (harmful)
species. But perhaps most important, these opposite poles also provide
the opportunity for an exchange of information and insight.