The' Scottish Naturalist. 31 



sides. On putting on sugar for the first time on a tree, it should be well rubbed 

 into the crevices of the bark, but afterwards a less quantity of the compound 

 and a slighter brushing will do. I may mention here that trees which have been 

 frequently sugared are generally more productive than trees sugared for the first 

 time : it follows, therefore, that we should not change our sugaring ground too 

 frequently, or without good reason. 



If we can find no trees, we must sugar some other objects, such as flowers, 

 leaves, posts, or stones. * Of flowers, ragwort and thistles are about the best ; 

 and on them the sugar may be dabbed, while on stones it may be applied in 

 stripes. 



If none of these can be found, it has been suggested that bunches of grass, 

 such as bent on sandhills, should be tied together and sugared, but in pre- 

 ference, I would be inclined to try the effect of rags soaked in the mixture, and 

 tied to short sticks. 



Thirdly, — "When to Sugar." 

 This may be considered under several aspects : — 



(1) The time to put on the sugar. 



(2) The time to examine it. 



(3) The seasons most productive. 



(4) The weather best suited, 



(5) The occasions on which not to sugar. 



(1) The time to put on the sugar should be immediately before dark. It is 

 possible (if we cannot do otherwise) to put it on several hours before dusk, and 

 to find the sugar productive, but as the scent is likely in a great degree to be 

 dispersed in that case, it is better to wait until the last moment of daylight. 

 Sugar put on after dark is probably (I say "probably" for I have not tried it), 

 still less productive than that put on too soon, for the reason that the scent has not 

 time to be spread about enough, not to mention the obvious difficulties attendant 

 on the application of the mixture. That sugar put on some hours before dark 

 is not unproductive, is evident, because ' ' old sugar'' {i.e., sugar put on the previous 

 night) is often worth examining. 



(2) The examination of the sugar may begin as soon as it is pretty dark, and 

 be carried on at intervals till dawn. Different moths have different hours of 

 flight, and up to midnight we find a constant succession of new arrivals. After 

 midnight, (according to Dr. Knaggs), the order of arrival is reversed, till just 

 before dawn we find the same species that came just after dusk. As few of us, 

 however, have sufficient energy to continue examining the sugar all night, two, 

 or perhaps three rounds, will be sufficient, especially if we begin our examination 

 not immediately, but half or three quarters of an hour after dark. My usual 

 number is two rounds, except when a very productive night tempts me to try 

 more. 



(3) "Which is the most productive season?" is a question not very easily 

 answered, as opinions differ thereon. In every month in the year I have taken 

 moths at sugar, but of course some months are much more productive than 

 others, The question arises, " Which are these months?" If I was to answer 

 from my own experience, I should say June and part of July, but I know that 

 while I have been finding moths abundant at sugar during that period in one 

 locality, friends in others have been experiencing the reverse, — their sugar being 



' I have counted forty-seven moths on a single stone. 



