MAN IN A WORLD OF INSECTS — DE LONG 425 



The majority of insect species have no economic status and are seen 

 only incidentally by man. They are considered as neutral. The re- 

 maining forms could be divided into two groups, the constructive and 

 the destructive. If man attempts to evaluate the role of his insect asso- 

 ciates, he will need to enter them on the ledger as either assets or lia- 

 bilities, namely, those that benefit him or those that do him harm. We 

 speak of many insects as being beneficial to man, and although we 

 may be reluctant to admit it, we are actually dependent upon insects 

 for much of our food supply, either directly or indirectly. In fact, 

 the peoples of the world could not be fed today except for their 

 assistance. 



INSECT ASSETS— THE CONSTRUCTIVE 



Insects and pollination. — Biologists in general have agreed that one 

 of the major benefits derived from insects is the production of crops 

 which result from their services as pollinating agents. It would be 

 difficult to estimate the value to man of pollinating insects, but the 

 sum is enormous. It has been demonstrated that at least 50 agricul- 

 tural crops depend on flower- visiting insects for pollination, or yield 

 decidedly more abundant crops when bees are present. This list as 

 reported by the U.S. Bureau of Entomology and Plant Quarantine in- 

 cludes most of the important fruits and vegetables, forage crops, 

 legumes, and certain special crops. The real value to man is the 

 production of seed and fruit. Without insects to effect pollination, 

 many species of plants will not set seed or produce fruit no matter 

 how well they are cultivated, fertilized, and protected from diseases 

 and pests. 



Although the honey bee is the most important pollinating insect, 

 it is but one of many species of bees necessary for the perpetuation of 

 flowering plants. Various species of flies, beetles, and other insects 

 also visit flowers and to some extent pollinate them. The Bombyllidae 

 are particularly known for their pollinating habits. The importance 

 of the honey bee is especially noted because it and certain wild bees 

 must obtain nectar and pollen in order to nourish both the young and 

 adults. This is not the case with other pollinating insects. 



Furthermore, agricultural development has seriously interfered 

 with the balance in nature by demanding enormous acreages for cul- 

 tivation. The nesting places of wild and native pollinating insects 

 have thus been destroyed. As a result the burden of pollination has 

 been increased to such an extent that wild bees are no longer adequate 

 or dependable. Honey bees must be introduced seasonally in certain 

 specific areas for pollination, and they have thus become the most 

 numerous of the flower- visiting insects. It is essential, nevertheless, 

 to work to conserve our native pollinating insects, since some species 

 of native bees are more efficient, bee for bee, than honey bees and will 

 work under more adverse conditions. 



