180 INJURIOUS INSECTS. 



while feeding on the bark of the willow, one perceives a few of them to 

 elevate their bodies, and a transparent substance evidently drops from them. 

 At first I was not aware that the substance thus dropping from these 

 animals was their excrement, but was convinced of it afterwards, for on a 

 more accurate examination, I found it to proceed from the extremity of 

 the abdomen, as is usual in other insects. On placing a piece of writing 

 paper under a mass of these insects, it soon became thickly spotted; holding 

 it a longer time, the spots united, from the addition of others, and the 

 whole surface assumed a glossy appearance. I tasted this substance, and 

 found it as sweet as sugar; and were it not for the number of ants, wasps, 

 and flies, which devour it as quickly as it is produced, it might, no doubt, 

 be collected in considerable quantities, and if subjected to the process used 

 with other saccharine juices, might be converted into the choicest sugar or 

 sugar-candy." 



Such is Mr. Curtis's account of honey-dew, with which we agree, yet 

 we find many well-informed people entertain a contrary opinion. Pliny 

 could not account for this substance, and hesitated to give it a name, and 

 even declares himself at a loss whether to call it the sweat of the heavens, 

 the saliva of the stars, or a liquid produced by the purgation of the air. 

 We believe that the Abbe Boissier de Sauvages, of Monpellier, was the 

 first to describe it as the excrement of Aphides. Duhamel observed it 

 dripping in such quantities from some willows by a river-side, that children 

 were catching it as it fell. He also observes in "Physique des Arbors," 

 that it flowed from nut trees in equal quantities, a circumstance quite 

 common in our nut trees, from the Aphis eoryli; but Duhamel does not 

 consider it the excrement of Aphides. Dr. Darwin, in "Phytologia," says, 

 "If it is voided by the Aphis, it is owing to their penetrating the sap- 

 vessels, and drinking more of it than they can digest." 



That the Aphides exist not by consuming the foliage of plants, upon 

 which they are found, but receive their nourishment by sucking out the 

 juices of the plants, is a fact well known to every observer of Nature. 

 Some, however, assert that this is the case only with such as are produced 

 by viviparous propagation, and that those produced from eggs may eat some 

 part of the foliage in spring, while they are in the larvae state, if they 

 ever can truly be said to be in such a state of their existence. Upon 

 this subject Dr. Darwin says, that "the Aphides produced from eggs early 

 in the spring may have a larva state, and that during that state they may 

 feed on the young leaves of peaches, apricots, nectarines, plums, and cherries, 

 and thus occasion them to curl and die; that those which are not from 

 the egg, only puncture the larger vessels which receive the vegetable sap- 

 juice from the roots; this they suck up, and live on to such an extent, 

 that it passes through them almost unchanged, falling on the leaves and 



