882 CHARLES PAuL ALEXANDER 
probable that this characteristic 1s fairly general among crane-flies. An 
interesting fact is that the great majority of specimens of photophilous 
species taken are either females, or males and females still in copulation, 
indicating a nocturnal or a-crepuscular oviposition or mating habit for 
these species. There are many of these species, among them being 
Erioptera septemtrionis, Limnophila adusta, Pedicia contermina, Nephrotoma 
ferruginea, Tipula apicalis, T. trivittata, and T. collaris. It is these 
photophilous species that are so commonly found in houses, they being 
for the most part species that came to the lights at some earlier time. 
ENEMIES 
At all stages of their existence crane-flies are beset by enemies. The 
larvae and adults are preyed upon by a great variety of insect-eating 
birds and amphibia, and by many predacious insects such as beetles, 
asilid and empidid flies, Odonata, and the like. The larvae are parasitized 
by certain tachinid flies (Siphona, Admontia), and many internal parasites 
(Gregarinidae, Bacteria) and fungous diseases (Entomophthora [Empusa]) 
often prove fatal to crane-flies in their early stages. It is at their periods — 
of transformation and while still soft and teneral that they are most sus- 
ceptible to attack and injury of all kinds. The adult flies often serve 
as carriers of little red mites of the genera Trombidium and Rhyncholophus. 
This condition is very general and a great range of species are affected. 
Many species of the family (Geranomyia, Dicranomyia, Limnophila, 
and others) live on the faces of vertical cliffs which are often wet with 
percolating and dropping water, and this results in a certain mortality 
due to the insects’ being struck by the falling drops and dashed into the 
mud. During heavy rainfalls the smaller crane-flies rest on the underside 
of the leaves of trees, while the larger forms escape injury by hiding in 
crevices of the rock or the bark or by remaining closely pressed against 
the trunks of trees. 
