l66 YORKSHIRE NATURALISTS' UNION. 



possess these traps and use them, I would suggest that at the 

 end of a future season we compare notes as to the best 

 evenings, highest number of specimens in the trap on any one 

 night, and the greatest number of species, also the number of 

 specimens and the number of different species of females cap- 

 tured. I would also suggest that where practicable a white 

 sheet be placed behind the light, after the manner of that used 

 at the lamps worked by the fen collectors. Very wet, very dark 

 and very warm nights, with some wind, seem especially favour- 

 able for an abundant harvest ; fine starlight or moonlight nights 

 very unfavourable. 



With a view of making future reports something more than 

 a mere recapitulation of species captured (not that I wish by any 

 means to underrate the importance of these lists), I would sug- 

 gest the following subjects as being especially interesting and 

 worthy of the closest attention on the part of Yorkshire lepi- 

 dopterists during the coming season ; they are all subjects on 

 which reliable information is urgently needed. May I ask all 

 my Yorkshire friends to help me in this great work ? I know 

 they can and I feel sure they will. 



Observations bearing upon tliese phenomena as observed 

 in Yorkshire or in the North of England should be sent to The 

 Naturalist, which is the organ of the Y.N.U., and I feel sure that 

 the Editor would be pleased to have such communications for 

 insertion. 



I St. — Instances of one species pairing with another species, 

 the sexes of each to be noted, time of day, and whether 

 eggs were subsequently laid, and if so whether they were 

 fertile, with particulars of the eggs, larvae, pupae, and 

 resultant imagines if any. 



and. — Where a number of any species of lepidoptera is bred, 

 whether the males or the females emerge the first, together 

 with the numbers of each where possible. 



Charles Darwin thought the males emerged first, but 



Trans. V.N.U., 1900 (pub. Dec. 1900). Series D, Vol. 5. 



