120 Mr. G. F. Scott- Elliot's notes 



Diptera is extraordinary. I suspect the shelter 

 afforded by these bays aud valleys has much to do with 

 this abundance. 



Speaking generally, these flower-haunting Diptera 

 appear to be far most frequent on plants which grow in 

 enormous numbers wherever they do occur. Ihus on 

 Spergiila arvensis I found Syritta, three species of 

 Platychirus, Bhingia, Empin vitripennis and many 

 Anihomyia, Scatophaga, etc. This was also the case 

 on the common watercress, which is visited by Volucnlla 

 homhylans, EHstalis arhustorum, E. sepulchralis , Helo- 

 phihis pendulus, Syritta pipiens, Platychirus dypeatus, 

 P. peltatuf!, Empis lici<hi, and fourteen other Diptera and 

 Coleoptera. Ou the more local and scattered N. pahistre 

 I only discovered three common Anthomyids. 



Probably this explains why it is that so many plants 

 have taken to contracting their inflorescence so that a 

 very large number of flowers cau be visited by insects in 

 a very short time. 'J'hus, of all the plants which 1 have 

 studied, perhaps the following are the most visited by 

 Diptera and other insects, viz., the dwarf elder, sheepsbit, 

 ITmheUifcra', particularly Cicuta and Angelica, and of 

 course the Composita', notably Aster tripoUuni. 



On flowers which come early in the spring or late in 

 the autumn, there is, in favourable weather, quite an 

 extraordinary number of insects. I consider this to be 

 probably due to the whole available insect force being 

 concentrated on just those few forms which happen to be 

 in bloom. 'J'he following list of visitors : — Hive bee, 

 five species of Bovihus, Pieris napi, EristaUn pertinax, 

 Sericomyia horealis, Platychirus albimanus, Syrphus 

 halteatus, S. topiarius, Antliumyia radicitm* would be at 

 once supposed to belong to some very high type of flower, 

 such as a Labiate, but in reality they were all caught on 

 the common bramble or blackberry, which probably 

 attracted them because the special bue-flowers were not 

 then in bloom. Similarly the early spring buttercup or 

 pilewort rejoices in a large number of guests, e.g.. Hive 

 bee, Mantiui napi, Melanostoma, Platychirus albimanus, 

 Empis piunctata, E. bilineata, Hyetodesia basalis, Chilosia 

 sp., Anihomyia sp., and Meligethes. 



'■■'• By the author, Miss Hannay, and IMr. J. C. Willis. 



