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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 

 T aeniorhynchus) ; note that some larvae adopt a nearly 

 horizontal attitude (C. concolor and Mucidus scata- 

 pbagoides) ; 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 ' 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 syphonic index number. 



