Link, O. fusca Link and O. lutea Cavan. He learned 
that the flowers of Ophrys speculum are visited not only 
byasingle species of insect, Scolia ( Dielis ) ciliata (Fabr. ),° 
but solely by the males. The females exhibited complete 
indifference to the orchid although visiting the flowers 
of species of Centaurea, Galactites, Malva and Reseda in 
search of food. Both sexes visit species of these genera 
and both the males and females then use the proboscis 
in sipping nectar. 
Scola ciliata is a member of the Scoliidae, a family 
of burrowing hymenoptera, whose burrows are made in 
sand-banks exposed to the sun. The males emerge from 
the burrows about a month earlier than the females, us- 
ually in March. The females lead an almost subterranean 
existence and leave the burrows chiefly in search of food. 
While waiting for the females to make their appearance 
(mating takes place only in the open air), the males may 
be seen exploring in sinuous flight the ramparts of Al- 
gerian fortifications and exposed railroad embankments. 
And it is just such places as these for which the plants 
of Ophrys speculum exhibit a predilection. The flowering 
season of the orchid coincides with the appearance of the 
males of Scola ciliata and during the long wait for the 
coming of the females, the male insects visit the orchid 
flowers, seeming to find in them a compelling attraction. 
There were questions here demanding deep thought. In 
the first place, why the indifference of the females? And 
in the second place, what attributes peculiar to Ophrys 
speculum were of a nature to attract one sex and not the 
other of an insect seeking food‘ 
Pouyanne established beyond any doubt that the 
tlowers of Ophrys speculum are not visited for nectar or 
P ; et 
“Pouyanne referred to this insect as Colpa aurea, In more recent ac- 
counts the name Dielis ciliata Fabr. has been used. In this paper | 
have adopted the view that Dielis is a subgenus under Scolia. 
[4] 
