Mosquitoes go through four phases: (1) ovum, (2) larva, (3) nympha, (4) complete insect.
The absence or extreme paucity of mosquitoes no doubt accounts for the infrequency of malarial fever in the interior.
I'm not taking chances that mosquitoes or whatever remain.
One noteworthy feature in Liberia, however, is the relative absence of mosquitoes, and the white ants and some other insect pests are not so troublesome here as in other parts of West Africa.
All it does is breed mosquitoes and attract snakes.
The genus with which Anopheles is most likely to be confounded is Culex, which is the commonest of all mosquitoes, has a world-wide distribution, and is generally a greedy blood-sucker.
Pierre shook his head and arms as if attacked by mosquitoes or bees.
Mosquitoes caught by the experimenters, and sent to London, produced malaria in persons who submitted themselves to the bites of these insects at the London School of Tropical Medicine.
The alleged occurrence of the disease in localities free from mosquitoes or without their agency is not well attested; its absence from other localities where they abound is accounted for by their being of an innocent species, or - as in England - free from the parasite.
The wide distribution of certain species is undoubtedly attributable to the agency of ships and trains; under natural conditions mosquitoes seldom travel far from their breeding grounds, although the powers of flight of some species are greater than has been supposed.
Following up this line of investigation, Major Ronald Ross in 1895 found that if a mosquito sucked blood containing the parasites they soon began to throw out flagellae, which broke away and became free; and in 1897 he discovered peculiar pigmented cells, which afterwards turned out to be the parasites of aestivo-autumnal malaria in an early stage of development, within the stomachwall of mosquitoes which had been fed on malarial blood.
He further found that only mosquitoes of the genus Anopheles had these cells, and that they did not get them when fed on healthy blood.
The result was that the houses were free from mosquitoes and no malaria occurred throughout the entire season, though there had been 40 cases in the previous year.
These mosquitoes or gnats - the terms are synonymous - belong to the family Culicidae and the genus Anopheles, which was first classified by Meigen in 1818.
When unhealthy situations cannot be avoided, they may be rendered more healthy by destroying the breeding-grounds of mosquitoes in the neighbourhood.
When a place cannot be kept free from mosquitoes the house may be protected, as in the experiments in Italy, by wire gauze at the doors and windows.
Mosquitoes in the house may be destroyed by the fumes of burning sulphur or tobacco smoke.
According to the experi ments of Celli and Casagrandi, these are the most effective culicides; when used in sufficient quantity they kill mosquitoes in one minute.
The existence of the parasite is maintained by a vicious interchange between its alternate hosts, mosquitoes and man,.
Short of suppressing mosquitoes, the parasitic cycle may theoretically be broken by preventing them from giving the infection to man or taking it from him.
Their alternate hosts are mosquitoes of the Culex genus.
- Celli, Malaria; Christy, Mosquitoes and Malaria; Manson, Tropical Diseases; Allbutt's System of Medicine; Ross, "Malaria," Quain's Dictionary of Medicine, 3rd ed.; The Practitioner, March, 1901 (Malaria Number); Lancet (Sept.
Of insects there are relatively few kinds; but ants, beetles and mosquitoes abound.
Flies, lice, gadflies and mosquitoes are the worst of the insect plagues.
Other flies act as diseasecarriers, including the mosquitoes (Anopheles), which not only carry malarial germs, but also form a secondary host for these parasites.
Mosquitoes are rarely troublesome; gadflies, and a large spider (hangeyu), which spins a web resembling golden silk, are common, as are scorpions and centipeces.
Mosquitoes and flies are everywhere, and the wasp and wild bee also.
The ticks (Ixodes) are not only injurious as blood-suckers, but are now credited with carrying the germs of Texas cattle-fever, just as mosquitoes carry those of malaria.
Mosquitoes, locusts and ants are also common.
Before the year 1899 mosquitoes had never been collected systematically, and had received little notice from entomologists, so that but few genera and comparatively few species were known.
The result has been that in subsequent years mosquitoes have been collected, studied and described by naturalists and medical men in all parts of the globe.
Nearly zoo genera and about 700 species of mosquitoes are now recognized, but in all probability the total number of species is not less than 1000.
In general appearance mosquitoes resemble many harmless midges (Chironomidae), but may be distinguished by the following characters.
All ordinary mosquitoes), and the Culicimorphae or forms without a piercing proboscis (Mochlonyx, Corethra, &c.).
The thirst for blood is stimulated by heat, and in temperate climates it is only during hot weather that mosquitoes are troublesome.
Some species of mosquitoes, such Female Anopheles costalis, Loew.
In tropical climates with a well-marked dry season mosquitoes pass into a semi-dormant condition during the period when there is little water in which to deposit their eggs.
The preliminary stages of all mosquitoes are passed in water, either fresh or salt, stagnant or slightly moving.
The nature of the breeding-place varies greatly according to the species, and while many of the mosquitoes that infest houses will breed even in the smallest accidental accumulation of water such as may have collected in a discarded bottle or tin, the larvae of other species less closely associated with man are found in natural pools or ditches, at the margins of slow-moving streams, in collections of water in hollow trees and bamboo-stumps, or even in the water-receptacles of certain plants.
, The majority of mosquitoes are dull in hue, but certain species are brilliantly coloured or conspicuously banded or spotted with white.
Six or seven species of mosquitoes are also the intermediate hosts of Filaria immitis, which infests the right auricle and pulmonary artery of the dog, and occurs throughout the tropics, in southern Europe, the United States of America, and elsewhere.
The surrounding country is mostly deep swamp and the station is most unhealthy; mosquitoes are present in millions.
Fortunately mosquitoes are not a serious plague outside a few marshy localities.
To the traveller, the most conspicuous among the Mexican insects, perhaps, are the butterflies, beetles, ants and the myriads of mosquitoes, midges, fleas and chinches.
Among the mosquitoes, which are extraordinarily numerous in some of the hot lowland districts, are the species credited with the spread of malarial and yellow fevers.
Insects are numerous, and of about 500 species of beetle some 80% are not known to exist elsewhere; cockroaches and green locusts are pests, as are, also, mosquitoes,' wasps, scorpions, centipedes and white ants, which have all been introduced from elsewhere.
Reptiles, sand-flies and mosquitoes are common.
The south wind is dry, cool and invigorating, and banishes mosquitoes for a time; the north wind is hot, moist and relaxing.
Mosquitoes are also abundant throughout the delta.
There are many large and poisonous spiders and flies; fleas and mosquitoes abound.
Among the Diptera, which includes a very wide range of genera and species, are some of a highly troublesome character, though on the whole, Mr Whymper did not find the flies and mosquitoes so.
His explorations, however, did not extend to the eastern region, where the mosquitoes are usually described by travellers as extremely troublesome.
In 1900-1901 Major Walter Reed (1851-1902), a surgeon in the United States army, proved by experiments on voluntary human subjects that the infection was spread by the Stegomyia mosquito,' and the prevention of the disease was then undertaken by Major William C. Gorgas - all patients being screened and mosquitoes practically exterminated.'
Mosquitoes are innumerable, and moths and ants of the most destructive kind, as well as others equally noxious and disagreeable.
Mosquitoes and sand-flies are the chief insect pests, and in some districts are very troublesome.
Mosquitoes, termites, bees, ants, centipedes, millipedes, locusts, grasshoppers, butterflies, dragonflies, sandflies and spiders' are found in immense numbers.
Perhaps the converse is more feasible in some circumstances - that is to say, preventing mosquitoes from having access to malarial persons, and so propagating the parasite in themsevles.
Although it had long been suspected that these insects were in some way connected with malaria and other diseases, while that the species now called Stegomyia calopus was the carrier of yellow fever had been asserted by Finlay as early as 1881, it was not until the closing years of the 19th century that the brilliant researches of Ross in India, and of Grassi and others in Italy, directed the attention of the whole civilized world to mosquitoes as the exclusive agents in the dissemination of malarial fever.
Mosquitoes are found in all parts of the world.
Mosquitoes are numerous in the wet lowlands.
An old popular belief current in different countries, and derived from common observation, connected mosquitoes with malaria, and from time to time this theory found support in more scientific quarters on general grounds, but it lacked demonstration and attracted little attention.