76 



NATURAL HISTORY. 



situations, where they pass the winter, coming forth again in the first mild weather of spring to deposit 

 their eggs and continue the species. 



As has already been stated, it is only the females (which have all the parts of the mouth 

 developed) that feast upon the blood of vertebrate animals ; the males feed only upon the nectar of 

 flowers, to which also the females will resort. They never seem to miss a chance, however, of 

 procuring the more nourishing food, and the irritation caused by their bites is pretty well known 

 to most people. The common English Gnat produces sufficiently disagreeable effects, but the 

 Mosquitoes of warm climates and of high northern latitudes are among the most formidable of 

 insect-plagues, and even in Central Europe the Mosquitoes seem to possess a wonderful power 

 of irritation. Their mode of operation is well described by Professor Westwood : " Thirsting," he 



HOUSE GNAT. (Culex ciliaris.) 



1. The male, enlarged. 2. Head of the male, magnified ; a, antennae; r>, palpi ; r, proboscis. 3. Antenna of the male still more magnified. 4. Egg- 

 noat. 5. Larva, magnified. 6. Head of larva still more magnified. 7. Mandibles and labrum further enlarged. 8. One of the comb-like hairs from 

 the mandibles. 9. Side view of pupa, magnified; a, case of antenna; (, I', I", cases of the limbs; w, wing-case; c, caudal leaves, front view. 10. 

 Gnat issuing from pupa. 



"for its evening meal, the little animal enters our apartments, and, instead of whirling, 

 like the Moths, around the light, it betakes itself to its employment, sounding an approach, however, 

 by a tolerably loud humming,* which, in our chambers, at least, is often sufficient to banish sleep. 

 Taking its station upon an uncovered part of the skin, with so light a motion as not to be perceptible 

 when it alights (although it will not hesitate to make its attacks occasionally through our thick 

 clothing), it lowers its rostrum and pierces the skin by means of its exceedingly slender needle-like 

 lancets, which are barbed at the tips, and, as by degrees it pushes these deeper into the skin, 

 the lower lip or sheath, in which they were enclosed when at rest, becomes more and more elbowed 

 towards the breast, until the whole length of the lancets is introduced into the skin. It is supposed 

 that, at the same time, it instils into the wound a venomous liquid, which, while it enables the 



It is only the females that produce this humming or trumpeting noise, and it has been calculated that the winga 

 vibrate 3,000 times in a minute. 



