SECOND REPORT OF THE DIRECTOR 1905 



45 



studying disease-bearing forms, since it is well recognized that 

 closely allied species are very likely to have similar habits. The 

 efficiency of ordinary repressive work also depends largely on a 

 correct knowledge of the species involved. It was difficult to 

 identify either larvae or adults of our native forms previous to the 

 appearance of Museum bulletin 79, a work which contains a series 

 of illustrations very nearly essential to their identification. A 

 material addition to our knowledge of these insects is given in 

 Museum bulletin 97, which contains a revised key for the separa- 

 tion of a large proportion of American Culicid larvae and is of 

 special interest because of the morphologic study of the terminal 

 abdominal appendages, particularly those of the male. We have 

 succeeded in homologizing these structures, have bestowed there- 

 upon a set of appropriate names and our studies have demonstrated 

 that these organs are of great importance to the systematist. 

 Careful morphologic stu lies have already been made of a number 

 of exotic forms, new material is constantly being received 

 and we should soon be in position to make other additions - to 

 the knowledge of this group. J. R. Gillett has been employed 

 for six months in rearing mosquitos and making microsco- 

 pic preparations. Some conception of the character and extent 

 of this work may be gained from the following statistics: The 

 State collection of Culicidae now comprises about 4600 pinned 

 specimens, many of them bred, over 1600 microscopic prepara- 

 tions and numerous vials containing alcoholic specimens of larvae, 

 a total of nearly 140 species being represented in the adult or larval 

 stages, many of them in both. It is proposed eventually to bring 

 together the results of these biologic and morphologic studies in a 

 comprehensive treatise on the mosquitos of the State. 



Aquatic insects. The studies of aquatic insects, begun in 1900, 

 have been continued. These investigations have already resulted 

 in a monograph of our dragon flies, special attention being given 

 to the much neglected immature stages, to a nearly as complete 

 account of our May flies, to important additions to our know- 

 ledge of the Caddis flies, and a portion of the true Neuroptera 

 (Sialiidae). The midges (Chironomidae and Simuliidae) have been 

 the subject of extended and comprehensive studies by Mr Johann- 

 sen, the results being given in Museum bulletins 68 and 86. Dr 

 James G. Needham and Cornelius Betten spent the summer in 

 investigating the aquatic insect fauna of Old Forge and its immedi- 

 ate vicinity. This work resulted in large additions to the State col- 



