CULICID^. 
565 
The scales on the wings, head, and body have frequently character¬ 
istic shapes in the different species and genera, and are therefore used 
in classification. 
Fig. 363 —Proboscis of female anopheles (after Nuttall and Shipley). 
LR. LABRUM. MN. MANDIBLES. HP. HYPOPHARYNX. MX. MAXILLA. 
LI. LABIUM. LA. LABELLA. P. PALPI. 
As is well known, female mosquitos are blood-suckers, and their 
proboscis is modified for the purpose (Fig. 363). It consists of a gutter¬ 
shaped lower lip (Labium) roofed in by the upper lip (Labrum) so as to 
form a complete tube, a sheath and support for the inner parts. These 
consist of a rather flattened blade-like “ hypopharynx ’ ’ and four 
sharp serrated needles (the two mandibles and maxillae), and it is these 
inner parts which do the actual work of piercing and sucking. If a 
mosquito be carefully watched while biting, it will be seen to begin by 
planting the tip of the proboscis on the skin. The tip bears two slightly 
swollen lobes (the labella), and when it is pressed against the skin these 
lobes spread out on each side, like a man’s hands when he leans on a table, 
so as to give support and steadiness to the proboscis. As the inner 
needle-like structures are pushed further into the skin between the two 
steadying lobes, the latter maintain their position at the surface, and in 
consequence the outer sheath (labium) of the proboscis does not really 
pierce the skin at all, but can be seen to bend elbow-like so as to allow 
