The Crane-Flies of New York — Part I 881 



In some groups (Discobola, Liogma, Cylindrotoma, Tipula ultima, 

 and others) the males mate with the females while the latter are still callow 

 and teneral, in some cases even waiting beside the pupal case for the female 

 to emerge, when she is at once engaged in copulation. In most cases, 

 however, the female is fully developed and mature before mating takes 

 place. When in copula most species rest quietly on some support, but 

 nearly all species are quite capable of flying while still mated if disturbed; 

 in such cases the larger sex takes the initiative — the female in the 

 Tipulinae, the male in Eriocera longicornis and Teucholabis. Cases of 

 mating between different species are rare, but in one instance the writer 

 has noted the copulation of Phalacrocera tipulina with Liogma nodicornis. 



Oviposition 



The method of oviposition varies with the species and according to the 

 structure of the ovipositor. In the forms with aquatic larvae (Eriocera, 

 Hexatoma, and others) the eggs are laid directly in the water, the fly dip- 

 ping during its flight. Many Tipula, such as T. iroquois, T. hella, and 

 others, deposit their eggs regularly and methodically in algal beds at the 

 edge of a stream. Tipula nohilis, one of the species having soft, blunt 

 valves in the ovipositor, lays its eggs in soft mud or in moss. Many species 

 of Limnophila deposit their eggs with great precision. The author has 

 observed females of Limnophila alleni flying about low over the earth in 

 cold, dark woods. They flutter along slowly and silently until a suitable 

 place for egg-laying is found, consisting of a moss-covered, rotten log and 

 the mud beneath it. The eggs are pushed firmly into their position by 

 the acicular tergal valves of the ovipositor, considerable effort being made 

 to place them securely. The rate of oviposition is not more than eight 

 or ten eggs a minute, the female often pausing to rest for several seconds 

 during the operation. When engaged in oviposition the fly is quite uncon- 

 cerned with other agencies and may be picked up by hand. 



The species of Tipula with a serrated ovipositor, as described on 

 page 875, undoubtedly have a specialized method of egg-laying, the 

 what this may be is not yet known. 



Photophilism 



Many species of crane-flies, in widely separated groups, are attracted 

 to light, such species being termed photophilous, or light-loving. It is 



