Article VI. — The Chironomidcu, or Midges, of Illinois, zvith par- 

 ticular Reference to the Species occurring in the Illinois River. By 

 J. R. Malloch. 



Introduction 



The family Chironomidcu includes a very large number of species 

 the adult forms of which, in the great majority of cases, are very dif- 

 ficult to distinguish from each other. The adults of the larger species 

 of the genus Chirononius and those genera closely related to it are 

 often mistaken for mosciuitoes, which they greatly resemble in general 

 appearance. No adult of this group, Chirononiincc, nor of the Tanypi- 

 lur, has as yet been recorded as biting, and it is only in the Ceratopogo- 

 nincc, the species of which are generally very much smaller and more 

 robust, much less resembling the Culicidce, that we meet with blood- 

 sucking species. Some of the species in this latter group, known lo- 

 cally as "punkies," are very persistent biters, and though of very small 

 size occur sometimes in such numbers as to cause considerable incon- 

 venience. This habit of some species in the Ccratopogonincc is not con- 

 fined to those occurring in America. In Europe, particularly in the 

 more northern parts, Culicoides pnUcaris Linne and several closely 

 allied species are so numerous and bite so persistently in the evenings, 

 during the months of June, July, and August, that it i.^' only by endur- 

 ing much discomfort that one can remain outdoors in the country, or 

 even on the outskirts of the towns in certain districts. This condition 

 prevails in Britain, and is more pronounced in Scotland, especially near 

 the many small lakes which exist, where conditions nre almost luicn- 

 durable. Several species which attack man and cattle are dealt with in 

 this paper. 



The early stages of most species of this family are passed in water 

 — rivers, lakes, pools, and streams, or in almost any receptacle contain- 

 ing the requisite amount of water; but some species of the Ccratopo- 

 gonincc are terrestrial in the larval stage, living underneath bark, under 

 boards, or beneath other objects lying on the ground, while some of 

 them are also met with in nests of Hynicnoptcra. A most peculiar 

 form of larva belonging to this group and living on submerged logs, 

 has been found by Garman in Kentucky*, and has also occurred in the 



*BulI. Ky. Agr. Exper. Sta., No. 159, p. 31, Figs. 27 and 28, 



