THE 
HEW PHYTOIiOGIST. 
Vol. XVI, Nos. 5 & 6. May & June, 191 7. 
[P ublished June 28th, 1917.] 
THE SYRPHID VISITORS TO CERTAIN FLOWERS. 
By E. & H. Drabble. 
D URING the year 1916 much attention was given hy the writers 
to the flowers visited hy the Syrphidae, a group of the 
Diptera. Our observations were made in several parts of England, 
principally in Derbyshire, Middlesex and Hertfordshire, and they 
supplement rather considerably the information given by Knuth 
(“ Handbook of Flower Pollination,” English Edition, Oxford, 
1906-09), by Willis and Burkill (“ Flowers and Insects in Great 
Britain,” Annals of Botany ix., 1895), by Lord Avebury, and 
by many other writers whose works we have consulted. 
The Syrphidae, popularly known as the “ hover flies,” are 
Cyclorrhaphous Diptera with muscid type of venation, but with 
long anal cell, closed subapical cell, and a vena spuria. They are 
generally brilliantly coloured flies, which hover—particularly the 
males—in bright sunlight, suddenly darting from side to side, and 
again hovering, and many are very difficult to “ net” on account of 
their extraordinarily rapid movements. 
The larvae of many species feed on Aphides; such are 
Pipizella, Melanostoma, Catabombn, Syrphus, Sphcerophorea spp. and 
Baccha. Others, such as Cheilosia and Platycheirus spp., are 
found in fungi. Others again occur in decaying vegetable matter 
and cowdung ; of these may be mentioned Leiogaster, Platycheirus 
spp., Rhingia ) Eristalis, Myiatvopa, Helophilus and Syritta. In 
the sap of diseased trees have been found the larvae of Xylota 
and Chrysochlamys, while those of Volucella seem to be confined 
to the nests of wild bees. 
The imagines of nearly all Syrphids are attracted by flowers, 
particularly by those with plentiful pollen and with exposed or 
slightly concealed nectar. Accordingly they play a very large part 
in pollination, visiting the flowers both for pollen, which they eat, 
and for nectar. 
It is not necessary to describe the structure of the mouth 
parts, as a sufficient account of them may be found in any good 
text-book of entomology, such as those of Sharp (“ Cambridge 
