692 AN INTRODUCTION TO ENTOMOLOGY 



thick tuft of hair at the caudal end of the body is black or blackish. 

 The larva of this species was first observed in Florida (Comstock '8i). 

 A detailed account of its habits was later published by Welch ('14), 

 who studied it at Douglas Lake, Michigan. It is at first a leaf-miner 

 in the leaves of the yellow pond-lily, later it is a borer in the leaf- 

 stallcs. Its habits are similar to those of the following species. 



The brown-tailed diver, Bellura diffusa. — Shortly after the dis- 

 covery of the preceding species in Florida, the writer studied larva? 

 with similar habits at Ithaca, N. Y. From these larvae were bred 

 moths which proved to be Bellura diffusa. In this species the anal 

 tuft of the female is dark brown. In the male there is a series of dark 

 tufts on the basal abdominal segments. 



The young larvae of this species were not observed ; doubtless they 

 are leaf-miners like those of the preceding species. The older larvae 

 live in the leaf-stalks of the pond-lily, a single larva in a leaf-stalk. 

 The larva bores a hole from the upper side of the leaf into the petiole, 

 which it tunnels in some instances to the depth of two feet or more 

 below the surface of the water. This necessitates its remaining below 

 the surface of the water while feeding. The writer has seen one of 

 these larvsi remain under water voluntarily for the space of a half- 

 hour. The tracheae of these larvae are unusually large, and we 

 believe that they serve as reservoirs of air for the use of the insect 

 while under water. The form of the hind end of the larva has also 

 been modified, so as to fit it for the peculiar life of the insect. The 

 last segment appears as if the dorsal half had been cut away ; and in 

 the dorsal part of the hind end of the next to the last segment, which, 

 on account of the peculiar shape of the last segment, is free, there open 

 a pair of spiracles much larger than those on the other segments. 

 When not feeding the larva rests at the upper end of its burrow, with 

 the segment bearing these large spiracles projecting from the water. 



The white-tailed Bellura, Bellura gortynoides. — In this species the 

 anal tuft of the adult female is white. The habits of the larva have 

 not been described. 



The cat-tail noctuids, Arzama and Archanara. — Two or more 

 species of noctuids infest the cat-tail plant, Typha, in this country. 

 The larvas of both are at first leaf -miners, later they bore in the stalks. 

 Our most common species is Arzama obltqtta. According to the 

 observations of Claassen ('21) the full-grown larva overwinters in its 

 burrow in the cat-tail plant and transforms in the spring. But the 

 late Professor D. S. Kellicott, who made a special study of this 

 species, informed me in a letter written in 1882, that the larva leaves 

 the cat-tail plant in the fall and conceals itself under bark, in old 

 wood and even in the ground until spring when it pupates, and 

 emerges as a moth in May. It is evident, therefore, that individuals 

 of this species differ as to the location in which they pass the winter. 



Figure 872 represents either a variety of this species or a closely 

 allied species. It was determined for me by Grote in 1882 as Arzama 

 obliqua. I collected larvae of this form in winter from under bark of 

 fence-posts near water. 



