I. 



Culicines. 



Chapter I. 



Morphological Remarks, 

 a. The Larva. 



In the following pages I have tried to elucidate some points in the anatomy 

 of the Culicin larvae and as far as possible compared the anatomical structures with 

 the use the larva makes of them. The chapter deals only with our Danish mos- 

 quito fauna; it would certainly be desirable if the contents could be based upon 

 larva material gathered in other regions of the world. In the terminology I have 

 followed the excellent work of HOWARD, DYAR and KNAB. 



The Head of a mosquito larva is generally wider than it is long, rarely almost 

 isodiametric as in Finlaya geniculata; it may be rectangular as in Tceniorynchus; it is 

 commonly vaulted, but may be flattened (Tceniorynchus) or, as in some of the species 

 of the genus Ochlerotatus, semiglobular. The anterior margin is formed by a narrow 

 clypeus furnished with two stout spines, between which the labrum is attached. The 

 greater part of the upper surface of the head carapace is occupied by the front or 

 epistome. It bears a number of setse, the number and arrangement of which are of 

 significance for classification (KNAB 1904 p. 175). Apart from some small tufts, the epi- 

 stome almost always bears three pairs of tufts, the preantennal tufts, at the root of the 

 antennae, provided with many and often long hairs; only in Finlaya there are three; the 

 two other pairs are either arranged in an arch over the epistome or they are arranged 

 on two lines anterior posteriorly. They are then described as lower and upper frontal 

 tufts. These tufts are rarely multiple in the Danish species. The number of hairs is 

 greatest in the genus Culicella (five or six) Calex, Theobaldia and Aedes. In the genus 

 Ochlerotatus the number is commonly only from four to one. The hair formula : two 

 strong hairs in lower frontal tuft and four in the upper, is characteristic of the group 

 O. excrucians, cantans, lutescens, annulipes. In 0. diantceus the arrangement of hair-tufts 

 and their number of hairs are more in accordance with that of the genus Culicella. 

 There is always most hairs in the upper frontal tuft ; the highest number I have found, 

 is six (C. morsitans) in Theobaldia annulata commonly four. The lower frontal tufts 

 have generally three or two, but these hairs are stronger than those of the upper 



D. K. D. Vidensk. Selsk. Skr., naturvidensk. og mathem. Afd. 8. Rsekke, VII, 1. 2 



