78 
Culicine Larvae 
The larvae of the Culicinae are superficially 
much alike. There are, however, marked differences 
in some features on closer examination. These differ¬ 
ences are to be found mainly in the syphon tube, the 
antennae, the mouth parts, and mental plate, and to 
a less extent in other structures. 
Note differences in naked eye appearance ; note 
the long worm-like Stegomyia larva and its wriggling 
mode of progression ; note the transparent and spiny 
appearance of some larvae (e.g., Melanoconion and 
Taeniorhynchus) ; note that some larvae adopt a nearly 
horizontal attitude (C. concolor and Mucidus scata- 
phagoides ) ; others a vertical attitude ( Stegomyia ) ; 
whilst the majority form a small angle with the vertical. 
Examine larvae under a low objective. Note the 
penultimate segment (eighth) which carries the syphon 
tube and a patch of scales known as the 4 comb.’ 
Note especially the following :— 
(i) The syphon tube. 
(ii) The antennae. 
(iii) The mouth parts. 
(iv) The anal papillae. 
The Syphon Tube. —This is formed of a single 
cylindrical piece of chitin, and contains the origin 
of the two main tracheae of the body. Note the 
small flap-like pieces of chitin forming a closing 
apparatus at the extreme tip. Measure the length and 
greatest breadth of the syphon tube ; note that in 
different species, and especially in different genera, 
the syphon tube varies greatly in its measurement. 
By dividing the length by the breadth a figure may 
be obtained which is useful in classification and may 
be termed the symphonic index number. 
