The Sources of Nectar and Pollen 371 



list of honey-plants at the close of this chapter. To the 

 product which the bee makes from sugar from these sources 

 the name plant honey-dew honey is given. 



Insect honey-dew. 



The main source of honey-dew is, however, not plant 

 secretion but insect excretion. Certain plant-sucking 

 insects, belonging to the order Hemiptera, such as plant- 

 lice (Aphidae), scale insects (Coccidse), leaf hoppers (Jas- 

 sidse), white flies (Aleyrodidse) and tree hoppers (Mem- 

 bracidse), all belonging to the Homoptera, suck the juices 

 of the various plants on which they are specifically parasitic 

 and the portion of the sap not utilized by the sucking insect 

 is ejected, falling on the leaves and stems of the plant and 

 even running off to the ground below. Many of these juices 

 are sweet and are gathered by bees exactly as they gather 

 nectar,, except that if nectar is available honey-dew is aban- 

 doned. This is carried to the hive, ripened and sealed, 

 making what is known as honey-dew honey. This substance 

 is high in its content of gums and is a poor food for bees in 

 winter. It was formerly believed that the honey-dew of 

 some aphids was secreted from the tubular processes on 

 the dorsal side of the abdomen but it is now established 

 that it is an intestinal excretion, just as in the other families. 

 Honey-dew is gathered by ants perhaps more than by 

 bees. 



The sugars in honey-dew honey are the same as those in 

 honey and the chief chemical difference is in the higher 

 percentage of gums. The flavor is usually poor, and most 

 honey-dew honeys are dark in color and granulate quickly, 

 often before sealing. An exception is that from the sugar- 

 cane leaf-hopper (Perkinsiella saccharicida) of Hawaii which 

 rarely granulates. Honey-dew honey is probably much more 

 common than is appreciated by beekeepers, for the excreting 

 insects are present in millions every summer and probably 

 many of our honeys contain small amounts of this substance. 

 It is not unlikely that the variation in gum content of hon- 



