The Aphides are remarkable for secreting a sweet, viscid fluid, known by the name of Honey-dew, the origin of which has puzzled the world for ages. Pliny says "it is either a certaine sweat of the skie, or some unctuous gellie proceeding from the starres, or rather a liquid purged from the aire when it purifyeth itself."[891]
Amyntas, in his Stations of Asia, quoted by Athenæus, gives a curious account of the manner of collecting this article, which was supposed to be superior to the nectar of the Bee, in various parts of the East, particularly in Syria. In some cases they gathered the leaves of trees, chiefly of the linden and oak, for on these the dew was most abundantly found,[892] and pressed them together. Others allowed it to drop from the leaves and harden into globules, which, when desirous of using, they broke, and, having poured water on them in wooden bowls, drank the mixture. In the neighborhood of Mount Lebanon, Honey-dew was collected plentifully several times in the year, being caught by spreading skins under the trees, and shaking into them the liquid from the leaves. The Dew was then poured into vessels, and stored away for future use. On these occasions the peasants used to exclaim, "Zeus has been raining honey!"[893]
In the Treasvrie of Avncient and Moderne Times, we read: "_Galen_ saith, that there fell such great quantity of this Dew (in his time) in his Countrey of _Pergamus_, that the Countrey people (greatly delighted therein) gave thankes therefor to _Iupiter_. _Ælianus_ writeth also that there fell such plenty thereof in _India_, in the Region which is called _Prasia_, and so moistened the Grasse, that the Sheepe, Kine, and Goates feeding thereon, yeelded Milke sweete like Hony, which was very pleasing to drinke. And when they used that Milke in any disease, they needed not to put any Hony therein, to the end it should not corrupt in the stomacke: as it is appointed in Hecticke Feauers, Consumption, Tisickes, and for others that are ulcered in the intestines, as is confirmed by the Histories of _Portugall_."[894]
The Aphides, like many other insects, sometimes migrate in clouds; and among other instances on record of these migrations, Mr. White informs us that about three o'clock in the afternoon of the first of August, 1785, the people of the village of Selborne were surprised by a shower of Aphides which fell in those parts. Persons who walked in the street at this time found themselves covered with them, and they settled in such numbers in the gardens and on the hedges as to blacken every leaf. Mr. White's annuals were thus all discolored with them, and the stalks of a bed of onions were quite coated over for six days afterward. These swarms, he remarks, were then no doubt in a state of emigration, and might have come from the great hop-plantations of Kent and Sussex, the wind being all that day in the east. They were observed at the same time in great clouds about Farnham, and all along the vale from Farnham to Alton.[895] A similar emigration of these insects Mr. Kirby once witnessed, to his great annoyance, when traveling later in the year in the Isle of Ely. The air was so full of them, that they were incessantly flying into his eyes and nostrils, and his clothes were covered by them; and in 1814, in the autumn, the Aphides were so abundant for a few days in the vicinity of Ipswich, as to be noticed with surprise by the most incurious observers.[896] Neither Mr. White nor Mr. Kirby informs us what particular species formed these immense flights, but it is most probable they belonged to the Hop-fly, _Aphis humuli_.