236 THE entomologist's record. 



1'fiE LIFE-jilgfORy OF Oe^[EI^I£ DI^P^]^.* 

 By C. NICHOLSON. 



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, (Bowies' New 

 Collection of English Moths and Butterflies in 12 prints, all draivn 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. Linnajus called it Phalaena (Bomhi/x) dispar ; Haworth, 

 Bomhyx dispariis ; then we have Hiibner with Porthetria dispar, and 

 Ochsenheimer 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 besto\ved on this species 

 because of the striking dissimilarity between the SL'xes. 



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. Eiley 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 Eeport 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 sjjread 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 Eeport for 1894, that about half the infested district (that is about 

 100 sq. miles) lias been cleared of the pest. The expenditure last year 

 amounted to about £15,000. One of the reasons given, in the Eeport 

 for 1893, for its great destructiveness in America is, that it was 

 introduced without its natui'al enemies ; and this is the reason why 

 those " insect pests which are of European origin have been far more 

 injurious " in Anierica " than they were ever known to be in their 



* Bead before The City of London Entomological Society, Sept. 18th, 1894. 



