134 THE EARLY STAGES OF TABANID^ 



and conditions of oviposition, Lecaillon thinks that as in tabanids 

 oviposition may take place, according to species, either in a dry or 

 in a damplocahty, "not only the embryo but also the larva" can live 

 under very variable conditions of humidity. Lecaillon considers that 

 observations on the larval life of Tabanus qualuornotatus verify this 

 hypothesis. 



Later, in 1905, again large numbers of egg masses of this species 

 were found by Lecaillon, and his first observations could be generalized 

 to some extent. The eggs were always laid on warm sunny days 

 in early June about the middle of the day, and almost without ex- 

 ception on dried out twigs of various herbaceous plants. In fact, of 

 sixty egg masses collected in 1905, not a single one was found on a 

 green leaf or stem. During the subsequent years, few exceptions to 

 this rule were noticed. In 1907, however, Lecaillon found an egg 

 cluster fastened to a green stem of a grass, and in 1908 a cluster fas- 

 tened to the dry branch of a tree (bouleau) which had been rammed 

 into the ground. Lecaillon discusses (1906) this fact, putting the 

 question whether we might be dealing with mimetic resemblance. 

 This he thinks hardly probable. The females, avoiding the green 

 objects, would alight only on twigs of grayish or blackish color. More 

 likely it seems to Lecaillon that the females oviposit on dry twigs 

 because these are more rigid than the green stems. In fact, it is 

 observed that during the act of oviposition, the stems of weeds on 

 which the insects alight are curved, especially when agitated by the 

 wind. On the dried out twigs the Tabanus is in a much more stable 

 situation and can with greater facility give to the egg mass its rather 

 complicated form.^^ 



The places where eggs had been deposited were in all cases exam- 

 ined on woody slopes distant from any water courses. This fact 

 alone is certainly sufficient to prove that the larvae of Tabanus 

 qualuornotatus are not aquatic but terrestrial. 



The egg masses are found in large numbers assembled in certain 

 places on hillsides which evidently present all the favorable conditions 

 to which the ovipositing females are adapted. This circumstance is 



^^Lecaillon's explanation is more than doubtful. Many species of tabanids 

 complete their egg masses on quite slender reeds and grasses. Also for Tabanus 

 quatuornotatus it remains doubtful by what stimuli it is attracted to the twig. 



