THE INSECT POLLINATORS 207 



all be found at times upon flowers, either wild or cultivated. 

 So far as cultivated crops are concerned, however, these 

 insects are much less important than are the bees, both on 

 account of their smaller numbers and the lack of barbed 

 hairs upon their bodies for catching and carrying the 

 pollen. 



TWO-WINGED FLIES 



In the great order of two- winged flies (Diptera) there 

 are hundreds of species that freely visit flowers. Some 

 come for nectar, some for pollen, some for both. The legs 

 and bodies of many of these flies are furnished with hairs, 

 to which the pollen becomes attached and by means of 

 which it is carried from the anthers of one blossom to the 

 stigmas of another. These flies, as a rule, however, visit 

 those flowers in which the nectar is more or less exposed 

 in shallow cups, and, except perhaps in the case of certain 

 fruit crops, they are not nearly so important as pollinators 

 as are the social bees. 



BUTTERFLIES AND MOTHS 



In the great order of scale-winged insects, the moths and 

 butterflies (Lepidoptera), the great majority of species are 

 especially adapted to living as adults upon the nectar of 

 flowers. Consequently, there are many plants the blossoms 

 of which are especially adapted to cross-pollination by 

 means of butterflies or moths. These insects have long 

 sucking tubes, each of which is commonly coiled like a 

 watch spring on the under side of the insect's head. When 

 the butterfly or moth visits a flower, however, it uncoils the 

 tongue and projects it forward to reach the nectar of 

 the blossom. Often these tongues are of extraordinary 

 length, and so it is not surprising to find that the flowers 



