30 AGRICULTURAL EXPERIMENT STATION. 



There is also a difference in the manner of attack. Some 

 species hover about for a long time, selecting a place to puncture ; 

 others dart in at once, giving scarcely any notice of their arrival ; 

 some fly at the least disturbance, while others can scarcely be 

 driven off when once they have tasted blood. The peculiarities 

 so far as they have been observed, will be noted under specific 

 headings. 



During the summer of 1904 I had the pleasure of being bitten 

 by Stegomia fasciata, the yellow fever mosquito, in Georgia. 

 This species has the singing habit developed in the most aggra- 

 vated form and will hover, as it seems, for hours before deter- 

 mining to bite. Ordinarily I can feel a mosquito when it alights 

 anywhere on my face or hands; but these little fellows I could 

 not feel. I knew when one had lit; but absolutely could not 

 locate it. Nor was there any immediate sensation of pain with 

 the bite. In fact the bite itself was not felt; but gradually at- 

 tention was directed tO' a sensation of pain coming on slowly and 

 increasing in intensity until it reached a point quite as acute as 

 anything I ever felt in New Jersey. 



It would seem as though I ought to be used to all sorts of 

 mosquito bites by this time ; but the persistent singing, the 

 inability to "swat" the culprits and the gradual development of 

 bites on every exposed portion of the body, effectually destroyed 

 sleep for that night. 



HOW A MOSQUITO BITES. 



If we watch a mosquito after it has settled for a meal, we will 

 observe that the head comes ever nearer to the skin, but that the 

 beak itself is not forced into it; on the contrary we may see that 

 the beak bends at or near the middle and that, what seems to be 

 a thin rod or lancet, comes from and is steadied by its tip. If 

 we wait until the insect is fully gorged, we will see that as the 

 puncturing structures are withdrawn the beak straightens and, 

 when it is ready to fly, they have disappeared entirely within the 

 covering structures. A mosquito has no mandibles or biting 

 jaws, and no structures that correspond to them. The beak that 

 is visible when the insect is examined is simply a cover or sheath 

 for the real puncturing structures that lie within it. These 

 puncturing structures when separated under the dissecting micro- 

 scope, resolve themselves into a series of five or six very fine, 

 slender rods ; two on each side and one, somewhat more flattened 

 and larger, in the center. This central piece is really a grooved 

 or trough-like structure, covered by a thin, flat strip that makes 

 the trough a tube. It is through this tube that the poison is 



