xciv. PRESIDENT'S ADDRESS. 



migration before we again see this splendid hawk-moth in 

 this country. Several other hawk-moths are amongst our 

 regular migrants, notably Sphinx convolvuli, which must reach 

 us in immense numbers, as it is often quite common locally and 

 of very general distribution. A record of fifty or sixty in a 

 season in one garden is not unusual, and yet there is every 

 reason to believe that none of these survive the winter, though 

 some may be the produce of moths which have migrated here in 

 the spring. 



There are many other species of moths, besides hawk-moths, 

 which must reach us in this manner, the unexpected captures of 

 them taking place occasionally, sometimes singly, more often a 

 few in different localities, but they never establish themselves, 

 and we cannot assign their sudden appearance to any other 

 cause. At the same time great caution should be used in 

 distinguishing between a true immigrant and a species which, 

 from some unknown cause, is either always rare, or is very 

 variable in its appearance. It must be the experience of any 

 entomologist who has observed the habits of moths in nature 

 that with most species, whatever may be the causes, the numbers 

 met with in the same place in different years fluctuate very 

 greatly, so that in some years a moth will not be observed at all, 

 whilst in others it is comparatively common. Considering the 

 very large number of eggs laid by most insects, there would be 

 no difficulty, other things being favourable, in their multiplying 

 themselves a hundredfold in one season, which would be quite 

 sufficient to account for an unusual abundance without any 

 migration. 



Two of our most regular visitors amongst the butterflies are 

 Vanessa Cardui and Colias Edusa, better known to most of us as 

 the Painted Lady and the Clouded Yellow butterflies. The 

 striking and brilliantly yellow appearance of the latter in its 

 flight is such that, if it is here, it cannot well help being 

 observed, even by non-entomologists, which cannot be said of 

 most of the moth immigrants. 



