0. L. Walton 5 



Area I had not received any complaints or noted any unusual abund- 

 ance of the larvae of the White Butterflies, and my attention was 

 first drawn to an attack upon Swedes and Rape in adjacent fields 

 upon a cliff farm near Fishguard. Subsequently I saw others, while 

 Cabbages were, in many places reduced to mere skeletons. I returned 

 to Aberystwyth by train and noted some damaged Swedes as soon as 

 the Survey Area was entered. I made about 40 enquiries, and dis- 

 covered that whilst not so severe as in S.W. Wales, these pests were 

 sporadically abundant within the Area. Following these enquiries 

 I visited a number of the places whence damage was reported. 



The larvae of Pieris brassicae and P. rapae damaged garden Crucifers, 

 and to a lesser extent Swedes from sea level to 1100 feet. The damage 

 to Broccoli and Sprouts, however, was not equally distributed ; steep 

 banks lying in the sun ; the upper parts of fields and similar hot, dry 

 situations suffered most, while gardens and fields in damp situations, 

 near rivers, etc., were least affected. 



Two of the more severe cases were reported from mountain valleys ; 

 one from the upper portion of the Ystwyth (about 700 feet) following 

 a swarm of butterflies M'hich were noted about the Swedes at the end 

 of August ; the other from the steep slopes of the Rheidol valley. 

 This latter was visited when the Swedes were being harvested, and 

 there was little difference in size between the roots from the upper 

 half of the field which had been badly stripped, and the lower which was 

 but lightly attacked, the damage having being done too late to seriously 

 affect growth. Both in Pembrokeshire and in the Aberystwyth Area 

 farmers reported that broadcasting lime and soot had been without 

 effect. Within the Survey Area one farmer tried dusting with Basic 

 Slag after a shower (on Swedes) and another had no success with a 

 dressing of Baking Powder applied to cabbages ! 



Mr D. J. Morgan the Agricultural Organiser for Cardiganshire in- 

 formed me that he had observed Keating's powder (Pyrethrum) used 

 upon Cabbage with excellent results. Commencing on September 28th 

 I experimented upon several rows of Cabbages in an Aberystwyth 

 garden ; dusting with lime produced little results, and watering with 

 brine practically none, but a dusting of Pyrethrum was rapidly effective. 



A large proportion of the larvae in Aberystwyth gardens were 

 parasitised, and quite half the larvae and pupae observed attached to 

 walls, etc., in early October showed the yellow cocoons of the Braconid, 

 Microgaster glomeratus. 



During September and October, 1915, I noted slight damage to 



