46 
THE LIFE-HISTORY OF OCNERIA DISPAR. 
I have chosen this insect as the subject of a paper because, having 
reared it repeatedly through all its stages, I have noticed several 
features in its history which led me to think that it would prove 
specially interesting, and furnish food for thought and discussion. 
I will deal first of all with its nomenclature. Why the moth 
received its English name, “ The Gipsy moth,” I do not know, but the 
female is figured under that name in 1742 by Wilkes, (Bowles' New 
Collection of English Moths and Butterflies in 12 prints, all drawn from 
life, pi. x., fig 2.), who seems to have been the first British author to 
notice it. Scientifically it is probably best known to entomologists as 
Liparis dispar, though it is now called by the name which appears in 
the title of this paper. It seems to have had no specific synonyms 
worthy of mention, although generically it has experienced numerous 
vicissitudes. Linngeus called it Phalaena ( Bornbyx ) dispar ; Haworth, 
Bombyx disparns; then we have Hiibner with Porthetria dispar, and 
Ochsenlieimer with Liparis dispar; then Stephens and Curtis with 
Hypogymna dispar, and finally Herrich-Schaeffer with Ocneria dispar. 
The generic name, Ocneria, is probably derived from the Greek 
ohieiros —“ sluggish ”; if this be the origin of the word, it is par¬ 
ticularly applicable to the female Gipsy moth. The trivial name dispar, 
meaning “ unlike,” is most appropriately bestowed on this species 
because of the striking dissimilarity between the sexes. 
As most of you are doubtless aware, this moth is remarkable from 
the fact that it has ceased to exist in a wild state in Britain and has 
degenerated into a purely domestic article of produce. On the 
Continent, however, it is anything but extinct; in fact, it occasionally 
becomes so excessively abundant as to strip large tracts of trees of their 
leaves. It is also unpleasantly in evidence on the other side of the 
Atlantic, in the State of Massachusetts, where Brother Jonathan 
employs many men whose sole business it is to keep the numbers of 
this insect in check, with a view to ultimate extermination. I wrote 
to Prof. Riley for information concerning the ravages caused by this 
species in the aforementioned State, and received in reply the three 
Reports now on the table; each of these, as you will observe, is 
entitled: “ Special Report of the State Board of Agriculture on the 
work of extermination of the Gypsy Moth.” The Moth seems to have 
been accidentally introduced into America about 35 years ago, and it 
gradually increased and spread to such an extent that, in 1890, £10,000 
was voted by the Legislature to be expended in efforts to get rid of it. 
Those efforts are still going on merrily, and you will see, by the map in 
the Report for 1894, that about half the infested district (that is about 
100 sq. miles) has been cleared of the pest. The expenditure last year 
amounted to about £15,000. One of the reasons given, in the RejDort 
for 1893, for its great destructiveness in America is, that it was 
introduced without its natural enemies; and this is the reason why 
those “ insect pests which are of European origin have been far more 
injurious ” in America “ than they were ever known to be in their 
native homes.” In the same Report twenty-four species of American 
birds (including the famous Blue Jay, immortalized by Mark Twain) 
are mentioned as feeding on the insect in three of its stages; there are 
are also four species of insects which have been found to destroy the 
ova, and seven true parasites which live in the larvae. I cannot give 
