160 
Psyche 
[September 
SOME CUBAN PHORID.E WHICH VISIT THE FLOWERS 
OF ARISTOLOCHIA ELEGANS. 
By Charles T. Brues. 
During a stay at the Harvard Biological Station at Soledad, 
Cuba some time ago, Mr. Robert M. Grey, the Curator of the 
Botanical Garden showed me a beautiful group of Aristolochia 
vines which are grown in one corner of the garden near his house. 
He told me that they were regularly visited by small Diptera 
which he thought were Phoridse and since I have been interested 
in the members of this family for many years we searched in the 
few flowers present at that time in hopes of finding some flies. 
None were to be found, but Mr. Grey promised to send me some 
at the season when the Aristolochias bloom in greater profusion. 
He did not forget his promise and I received recently a series of 
specimens which include two common species of West Indian 
Phoridse. These are Dohrniphora venusta Loew and Aphiochceta 
scalaris Loew, both present in apparently about equal numbers* 
It is of course well known that various small insects, par- 
ticularly Diptera, enter the flowers of Aristolochia through the 
corolla tube which in some species is lined with reflexed hairs 
that prevent the escape of the visitors until the withering of 
stigmas and the opening of the anthers. Then the barricade of 
hairs withers likewise and the insects escape. As the flowers are 
protogynous, cross fertilization is affected by the first entrance 
of the insects if they come from another flower, and they later 
leave with pollen acquired toward the end of their imprisonment. 
Several observers have recorded the insect visitors of a 
number of species of Aristolochia (Spengel, Hildebrand, Delpino, 
Correns, Carr 1 ) and find that most of the insects are small Dip- 
tera of various kinds. Verrall (British Flies, vol. 1, p. 47) noted 
in England that Aristolochia clematitis is visited most commonly 
by gall midges (Itonididse), although Muller and Delpino found 
References to many earlier publications are contained in Knuth’s well 
known Bliitenbiologie vol. 2, pt 2, pp. 366-372; Carr’s account is in the En- 
tomologist’s Monthly Magazine, vol. 60 (1924) p. 258). 
