496 
HONEYDEW 
, move them to new pastures, care for their 
eggs, and build over them covers of earth 
or cow-sheds to keep them warm. Ants 
also estend their protection to scale-insects. 
The term honeydew should be rigidly re¬ 
stricted to the sweet excretions of insects 
gathered by honeybees. Nectar is the se¬ 
cretion of nectaries whether floral or ex¬ 
tra-floral. It has been asserted by many 
beekeepers and not a few botanists in the 
past, that there is a third sweet liquid, 
which, under favorable weather conditions, 
is exuded directly by the leaves. The 
statement of Gaston Bonnier is often 
quoted to the effect that he had often seen 
trees on which there was not a single plant- 
louse, covered with a sweet liquid which 
exuded from the leaves. Cowan, editor of 
the British Bee Journal, gives the follow¬ 
ing opinion: “We are perfectly aware that 
opinions are divided as to the source of 
honeydew; but we agree with those who 
think it generally is an exudation from the 
pores of leaves under certain conditions 
of the atmosphere, -altho it may sometimes 
be produced by aphides. We have on sev¬ 
eral occasions examined trees producing 
honeydew in abundance that were free 
from aphides.” Many similar views might 
be given. But in the majority of cases it 
has been conclusively shown that the sweet 
liquid found on the foliage of trees is of 
insect origin, and that the assertions to 
the contrary were based on insufficient ob¬ 
servation and superficial investigation. 
Recent investigations by Davidson and 
Teit, however, show that from the tips of 
the leaves of the Douglas fir in British Co¬ 
lumbia, and Washington State west of the 
Cascades, there is exuded a sweet liquid in 
large quantities. “Fir sugar” was known 
to the Indians of British Columbia long 
before the discovery of America, and in 
recent years its presence has repeatedly 
been reported by beekeepers, but it does 
not occur every year. The sugar-yielding 
firs (Pseudotsuga Douglasii) are confined 
chiefly to the dry belt of British Columbia 
between the parallels of latitude 50 and 51 
degrees and the meridians of longitude 121 
and 122 degrees. The sugar is not formed 
on trees in the dense forest, but only on 
those in comparatively open areas, on gen¬ 
tle slopes facing the east and west, during 
hot summer droughts. In leaves of the 
Douglas fit exposed to continuous sunlight 
a larger quantity of carbohydrates is 
formed during the day than can be stored 
or earned away to the growing tissues. In* 
the hot dry atmosphere transpiration 
ceases and the leaves become gorged with 
water, which is f-orreed out thru their tips. 
A beekeeper at Victoria states that many 
of the firs, particularly isolated trees, are 
well spattered with the exudation, and the 
needle-like leaves studded with pale amber 
diamouds. A large number of bees gather 
the liquid and in some years two or three 
supers of sections are filled with it. The 
honey is fair in quality, pale amber in 
color, with rather dark cappings. It crys¬ 
tallizes quickly. By the evaporation of 
the water the liquid is transformed into 
white masses 14 inch to 2 inches in dia¬ 
meter. This solid may again be dissolved 
by rain and recrystallized in patches at 
the base of the tree. 
A beekeeper living in the Olympic Na¬ 
tional Forest, Ore., 21 miles from Port 
Angeles, reports that his bees stored 150 
pounds of fir sugar during a very dry sea¬ 
son. The following winter many bees died 
from dysentery, which was attributed to 
the effects of the sugar. This seems very 
probable, as the composition of this excre¬ 
tion is very different from that of floral 
honey. It contains among other constitu¬ 
ents nearly 50 per cent of the rare sugar, 
melezitose. 
It is certainly not improbable that 
other species of conifers may under spe¬ 
cial climatic conditions exude a sweet liq¬ 
uid. In Switzerland about 40 per cent of 
the honey crop is gathered from the weisst- 
anne (Picea excelsa), a fir tree. From an 
excretion found on the leaves of this fir 
tree the beekeepers in the Vosges Moun¬ 
tains, the Black Forest, and in parts of 
Switzerland harvest large crops of “honey¬ 
dew,” also called “waldhonig.” J. A. Heb- 
erle believes that this honey is of plant ori¬ 
gin, since metereological conditions seem 
to determine its production. Unfortunate¬ 
ly most assertions that the leaves of coni¬ 
ferous and hardwood trees exude occa¬ 
sionally a sweet liquid are based on ob¬ 
servations that are too superficial to be 
conclusive. But in the case of the Doug¬ 
las fir the investigations of Davidson and 
Teit appear to establish beyond question 
