BEES WHICH VISIT ONLY ONE KIND OF FLOWER 



adopted this method of visiting flowers to avoid competition 

 in gathering pollen for brood-rearing. But this is not the fact 

 and it can be shown that only a part of the available flower-food 

 is gathered by bees. The commonness of an insect species 

 does not depend alone on the quantity of food obtainable, e. g., 

 occasionally the forest-caterpillar {Heterocampa guttivittd), 

 which feeds on the leaves of deciduous trees, appears in count- 

 less numbers, defoliating acres of the woodlands and apparently 

 threatening the entire destruction of the hardwood forest; 

 but it speedily disappears again and becomes so rare that its 

 presence is unnoticed. The size of the bee fauna is likewise 

 limited by other factors than the food supply, the most im- 

 portant being insect parasites which destroy annually vast 

 numbers of bee larvae. 



It is desirable to consider a few specific instances where there 

 is unquestionable evidence of a surplus of flower-food. In 

 Riverside County, Cal., the orange-bloom secretes nectar so 

 freely that it drips upon the clothing of the pruners, and at 

 the end of a day's cultivating in the groves it is necessary to 

 wash the horses and harnesses. Large quantities are lost each 

 year for want of bees to collect it. Hundreds of acres of the 

 sandy, coastal plain of Georgia are covered with the bushes of 

 the common gall-berry {Ilex glabra). It remains in bloom for 

 about a month. The secretion of nectar is constant and but little 

 affected by the weather; but this sea of flowers is not frequently 

 visited by insects. Immense quantities of fine honey are lost 

 annually because there are no bees to gather it; furthermore, it 

 is not easy to overstock a gall-berry region with the domestic 

 bee, and in one instance 362 colonies did nearly as well as 100 

 previously. The production of honey in Iowa is placed at ten 

 to twelve million pounds annually ; but according to a conserva- 

 tive estimate by Iowa apiarists of great experience, it is possible 



115 



