252 Willis and Bur kill — Flowers and 
distinctly scarce in the district. It must be remembered 
that, as Macleod has shown (18), they become less numerous 
as the season advances. Of the other Hymenoptera, Vespa 
sylvestris was abundant on Angelica , but was never seen on 
any other plant. The Ichneumonidae and their allies were 
found in great numbers on the Umbellifers, and on Senecio , 
& c. Whether or not they visit the flowers for floral food 
they must be of some importance in fertilization. 
Of the Syrphidae, 25 species were observed, making 89 
(species-) visits. The commonest were (in order) Eristalis 
tenax (on 9 flowers), E. pertinax (8), Platychirns albimanus 
(8). Rhingia rostrata was abundant on Centaur ea and S tacky s, 
but was never seen on any other flower. Altogether the 
number of visits made by these flies forms more than a fifth 
of the total, but it is known that they increase in (propor- 
tionate) number in late summer (see 341 b and 18). 
The short-tongued flies number 50 species with 124 visits 
(the largest number for any group). The commonest species 
belong to the genera Lucilia (esp. L. sericata\ Trichophthicus , 
Anthomyia (A. radicum on 22 flowers), Hyetodesia , Mydaea , 
Scatophaga. No species of any other genus was seen on more 
than 4 flowers. In individuals, these flies far outnumber the 
other groups, and must be of considerable importance in 
fertilization. 
Of the Coleoptera (it species, 23 visits) the only common 
ones are species of Meligethes (abundant in nearly every 
flower) and Crepidodera ferruginea . Of the Hemiptera 
(6 species, 22 visits) Anthocoris was common. 
If we compare the percentages of visitors of each class of 
insects (foot of Table I) with those given by Muller (Fert. of 
Firs. p. 654), it will be seen that considerable differences 
exist between the composition of the flower-visiting insect 
fauna in Germany and in South Scotland, as shown in the 
figures. The Lepidoptera (11*3 per cent, against 6-9 per cent.), 
Syrphidae (21-2 to 19*6), other Diptera (29*3 to 10*9) and 
miscellaneous insects (Hemiptera, &c.) (5*4 to 0-9) are more 
numerous in proportion in Scotland, whilst the long-tongued 
