426 



MOSQUITOES 



as to need no description, but the details of their structure is as 

 little known by most people as are those of the structure of other 

 insects. The diagram on page 425 (Fig. 188) illustrates the 

 details of the parts of a mosquito which are of most use in iden- 

 tifying and classifying. The sexes can be distinguished most 

 readily by the antennae; in the female (Fig. 190A) they are long 

 and slender with a whorl of short hairs at each joint, whereas in 

 the male (Fig. 190B) they are shortened and have a feathery 

 appearance, due to tufts of long and numerous hairs at the 

 joints. In many mosquitoes the palpi also furnish a means of 



Fig. 190. Heads of female (Ji) and male (q) mosqmto, Culiseta incidens: 

 ant., antenna; b. j. ant., basal joint of antenna; label., labellum; palp., palpus; 

 prob., proboscis. 



distinguishing the sexes; they are usually long in the males 

 but short in the females, but in Anopheles they are long in both 

 sexes, and in some mosquitoes, e.g., Uranotcenia, they are short in 

 both. 



The proboscis, which is the most fearful part of a mosquito, 

 also differs in the sexes, and fortunately is so constructed in the 

 male that a mosquito of this sex could not pierce flesh if he would. 

 At first glance the proboscis appears to be a simple bristle, some- 

 times curved, but when dissected and examined with a micro- 

 scope it is found to consist of a number of needle-hke organs 



