BROWN MOSQUITO.
Observe the proboscis in front of the head.
Gnats breed in standing water, fresh or otherwise, but seem to prefer rain-water, for they are very numerous about small pools and water-butts. Consequently they were formerly far more abundant in England than at present, when the fens were still undrained, and when every house had its rain-water butt. The females of some species construct small rafts of eggs, which float about on the surface of the water till hatched, and then produce small maggots with a breathing-apparatus at the end of the tail. In this condition they swim head-downwards, while the more compact pupa floats head-upwards. They may be destroyed by pouring a little kerosene into their breeding-places; and as this floats on the surface of the water, it does not interfere with the use of the water in water-butts, which is usually drawn off by a tap below. The males of gnats often have feathered antennæ and long, slender legs. The females, however, are more nocturnal in their habits, and come into houses in the evening, and keep people awake by their humming and painful "bites," or rather punctures, which frequently cause a distressing irritation for a day or two afterwards. What is worse is that they are now known to disseminate various diseases, such as elephantiasis and also malarial fever of every kind, in this manner—from the comparatively mild ague of the English fens (now nearly extinct) to the terrible malaria of Southern Europe, India, and Africa, formerly attributed to the unhealthy atmosphere of marshy countries, or to exposure to the night air in warm countries, but now known to be caused by the bites of the gnats, or mosquitoes, which breed in swampy places, and fly about in the evening. It is believed that only certain species of gnats convey the germs of these diseases; and it has been stated that, though ague-bearing species of gnats are still found in England, those which have been examined for the purpose have been free from these germs, and are therefore incapable of propagating the disease.
Photo by W. P. Dando, F.Z.S., Regent's Park.
HORNET ROBBER-FLY.
Common in the south of England.
Photo by W. P. Dando, F Z.S.] [Regent's Park.