174 THE entomologist's record. 



wood. In 1894, my friend Mr. Potter took 14 T. crepuscidaria and 

 5 ab. delatncirmis, making a grand total of 881 of the former and 227 

 of the latter, or 608 specimens of the species from one wood in five 

 years. The gradual increase of the dark form will be seen by a com- 

 parison of the figures given under their respective years. That the 

 ab. delamcremh is the form best adapted to survive in the struggle for 

 existence is apparent to every one who sees both forms in siUi, for the 

 type is fairly conspicuous, as it sits with outstretched wings on the 

 darkened trunks of the trees, whilst the dark form requires keen and 

 educated vision to detect. It would appear that in this locality the 

 type is being slowly supplanted by the variety in this district, for not 

 only is the ab. delamerensk becoming commoner, but intermediate 

 forms are now much more numerous than formerly, I have occasion- 

 ally obtained both forms at rest on all the trees which occur in this 

 wood, but I obtained the majority from beech, birch coming in a 

 good second. They generally occur at from four to five feet from the 

 ground, but I have taken and seen them at distances ranging from six 

 inches to fully twelve feet. As a rule they sit on the N.E. side of the 

 tree, but I have taken them from all sides. Their principal time of 

 emergence is from 2 to 4 p.m. It seems to be a very hardy species, 

 as I have taken them freely whilst snow, hail, sleet or rain has been 

 falling. It is certainly not a double-brooded species at York. Bred 

 specimens of the ab. delamercnsis are much darker than captured ones. 

 I have beaten the larvae from birch and sallow in June, and reared 

 them from the egg on both sallow and birch. — W. Hewett, York, 



drOLEOPTERA. 



Collecting Coleoptera — Evening Sweeping. 



By W. H. BENNETT, F.E.S. 



Evening sweeping is a method of collecting Coleoptera, which no 

 one who wishes to get a complete and thorough knowledge of all our 

 species, can afibrd to neglect, at the same time it is a very unequal 

 method. On one occasion you may do extremely well, and then many 

 expeditions will be totally unproductive. I know of no other way of 

 collecting which involves, at times, so much work for a very small 

 return. At the same time, however, it must be remembered that there 

 are many species which are hardly ever met with in any other way. 

 The species of Colon, Anmitoma, Cidniu, Cyrtma, Hi/dnnhins, A(jarico- 

 jdiai/Hs, Triarthnm, Thali/cra, etc., are almost exclusively known from 

 captures made by evening sweeping. On the other hand, I have met 

 many collectors who have told me that they rarely get anything in this 

 way, so that a few notes on this subject may not be without interest to 

 those who have not devoted much attention to this style of collecting. 



In this paper I shall deal only with my own experiences, and these 

 have been almost entirely confined to the districts around Hastings ; 

 so that collectors in other districts may not always employ exactly the 

 same methods, or get the same results. 



First then, as to the time at which evening sweeping should begin. 

 This varies according to the time of the year. Early and late in the 

 season I have found that the afternoon is often more profitable than 



