﻿355 



NOTES ON THE EHOPALOCEEA OF WEST NOKFOLK. 

 By A. Smith. 



Of this division of the Lepidoptera, sixty species are given as 

 having occurred from time to time within the area of the Fens. 

 The present notes merely refer to this immediate neighbourhood, 

 say within the confines of a day's walk. Many other species are 

 said to be found at a distance of a mile or two ; but three or four 

 years of close observation has produced only the limited number 

 of sixteen species. I may add that a drive to such places as 

 Wisbeach, March, Manea, Upwell, through Bardolph Fen to 

 Lynn, or prolonged walks in various directions, has not afforded 

 any additional species to those found at home. I can walk along 

 one ditch alone and find eleven of the number in one day in 

 August, and during that month the lot could be seen there, with 

 one exception, the orange-tip. The district is poor as regards 

 species. Agriculture, with its consequent drainage improvements, 

 has deprived the fens of some grand old species, while the advan- 

 tages of cultivation have only favoured such common ones as the 

 whites, small tortoiseshell, and the like. The present notice 

 chiefly refers to the last three seasons. The lateness of appear- 

 ance of the perfect insect, in most instances, may be accounted 

 for by the flatness of the district, the prevalence of east winds, 

 and the backwardness of vegetation. 



Pieris brassicce. — The remark sometimes applied to this 

 species, that it outnumbers nearly all our native butterflies, does 

 not apply to this locality, for, in reality, it is numerically deficient 

 when compared with P. rapce, and sometimes, as was evident this 

 season, with P. napi. The fly is fairly abundant during the 

 latter half of May and throughout June ; with the advent of July 

 it falls off rapidly, abounding again when August is reached, being 

 the most profuse in that month, and on to the first week in Sep- 

 tember, when the species begins to fail. Larvse numerous on 

 cabbage ; have seen them feeding down to the first week in 

 November. 



1888: May 21st— September 19th. 1889: May 8th— Sep- 

 tember 17th. 1890 : May 7th— September 19th. 



P. rapce. — This is really the domestic butterfly, as regards 

 abundance in this restricted spot. It far exceeds the last, begin- 

 ning its career occasionally in April, becoming very numerous in 

 May and June ; a slackness during the first ten days of July is 

 succeeded by great numbers from that time onwards. During 

 August the gardens, pastures, and more especially the clover 

 fields, are alive with the whites, of which this species is by far 

 the greatest contributor. In September it is also plentiful, 

 appearing less after about the third or fourth week. I have 



2 e 2 



