24 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
of Werneburg's* of the German Maerolepidoptera 3.4 per cent, hiber- 
nated as egtf> 00.9 per cent, as larva*, 28.2 per cent, as pap®, and 1.5 
percent, as imagines, while in considering a single family the result stood 
entirely different. Thus all the Zyga*nidie hibernated as larvie, most 
SphingidflB as pupae, and of the butterflies 9 per cent, in the egg, 54 per 
cent, in the larval, 28 per cent, in the pupal, and 9 per cent, in the 
imaginal state. Thus it appears that insects which, not to take too 
narrow a limitation of genera, belong to one and the same genus, may 
hibernate in wholly different stages. 
Of many species of insects only the females hibernate after impreg- 
nation in autumn, /. e., many gnats and our common paper wasp (Vespa), 
while the honey bees tolerate no droues in their hives, so that only the 
queen with the workers lives through the winter. 
But abnormal meteorological phenomena may so effect such chauges 
that a species of insect may hibernate in a different stage of develop- 
ment from what is customary. Indeed there are cases where au insect 
may, though rarely, live through the winter in another of the four 
stages of metamorphosis than the usual one, for it has been observed 
that the pine Gastropacha lives through the second winter as pupa. 
(Ratzeburg : Die Forstinsekten, ii., 147, Anm.) On the other hand, it is 
very common for caterpillars, which seek winter quarters when half 
grown. This they have to do as very young animals. Thus the pine 
Gastropacha hibernates after the first molt, instead of, as usual, after 
the second. 
Insects which have generations requiring several years must natur- 
ally hibernate several times. This may occur in the same or in different 
stages of metamorphosis; thus, for example, the one, two to three years' 
generation of the May fly remains as a larva in the water, while the 
May beetle passes three winters as a larva, but the fourth as au imago.t 
For the following interesting remarks we are indebted to Judeich and 
Nitsche's work on Forest Entomology : 
Diseases of trees produced by the attacks of insects. — Various deformi- 
ties and alterations of the wood, branches, and leaves result from the 
attacks of borers and bud and leaf devourers. Before the tree com- 
pletely heals there is a more or less long period during which the tree 
assumes an abnormal, morbid appearance. Such appearances in which 
the disease affects the growth of the wood are : 1. The appearance of 
unusual new structures, such as leaves, etc., both in form and dimensions. 
2. The origin of repaired parts from representative growths or sleeping 
buds. 3. The diminution of growth. 
The appearance of unusual new growths. — In general the changed 
sickly new growths are smaller and more sparse than the normal. A 
thinner foliage in the year after the damage is generally the result of 
*A. Werneburg. Der Schuietterliug und seiu Leben. 8°. Berlin : 1SV1. 
tThe foregoing remarks on insect-generations and hibernation have been trans- 
lated from Jndeicb and Nitsche's valuable work on Central European Entomology. 
