Ae. (Aed.) vexans Meig.
Widespread within all areas of the Holarctic, except tundra, look. In the southern part of the range comes in the Oriental and Ethiopian regions. In the USSR extended north to the forest zone, although it is wedged on floodplains (Monchadsky, 1951). In Kazakhstan, the ubiquitous, reaching a high population in the south and in the north of the country. It should be noted in this mosaic of distribution, due, we believe, confined to certain environmental conditions. In the desert, semi-desert and steppe zones of the Republic of substantial warming of solar radiation due to high larval habitats, hatching is timed to overgrown areas of flood plains of rivers flowing here. In the north and east is where the sun exposure is less, its development is confined to a more open or slightly overgrown ponds. In Kazakhstan, there are two subspecies of it, well differentiated and morphologically indistinguishable on ecology.
Ae. (Aed.) vexans vexans Meig.
Ae. vexans vexans Polycyclic is relatively heat-loving species. Its breeding places and circumstances, are very similar to Ae. with. caspius and Ae. with. dorsalis. The larvae develop in many ephemeral, temporary and semi-permanent water bodies (clusters melt water, floodplain flooding, water logging and filtration Zatoka irrigation network, the outputs of groundwater water, Copanca, ditches, canals, ponds, filtration fields, lakes and wetlands with fluctuating water levels). In water with a high concentration of salts hatching is unchecked. Prefers ponds, slightly overgrown submerged vegetation, and are surrounded by trees and shrubs and partly shaded by them. In the south and south-east of Kazakhstan meet these requirements flood waters, and on the north and east – forest spills. In reservoirs of the larvae of this species are found together with Ae. sticticus.
Development observed in water with a salinity of 641 to 3515 mg / L, slight shift of the reaction to the alkaline side (pH 7.2-7.6) and different ratios of some compounds with limits. At higher salt concentrations hatching is not marked, although these waters are often caught within the activity of this kind.
Range of temperatures at which the possibility of development, is in range 14-34 ° (Shlenova, 1952). In extreme versions of it in one case, a tightening of development, and in the other (upper limit) – high mortality of larvae. Optimum development 29 – 30. Thus, the criteria for this type of temperature close to the Ae. with. caspius, but its development and mass hatching occur much later. This is explained by the specificity requirements Ae. v. vexans to environmental conditions. As already noted by some researchers (Shlenova, 1952 Monchadskip, 1950 Sazonov, 1959) development larvae began only after refilling water stations with clutches of this species, which Shlenova MF (1952) explains the need for the passage of drying out of eggs.
According to our observations in Kazakhstan, the hatching of the larvae can be carried out without having to double-covered with water. Females Ae. v. vexans died in the cages, but the eggs to water does not set aside. But on a wet filter paper made of masonry willingly, mostly at the edges of her. In all cases of eggs laid after 8-9 days at 23-33 ° vyplazhivalos 68-79% of the larvae. Of the remaining eggs and nests contained a certain time on a wet paper and then dried, hatching was observed only after the re-fill with water. Conclusions Shlenova MF (1952) also confirm that the normal passage of embryonic development and hatching period of drying required. While for subsequent reactivation of eggs to the effects of high (30-34 ") temperatures. In Kazakhstan, according to experimental data, it is applicable only for the eggs, which, for various reasons, be inhibited embryonic development. Main part of them under favorable conditions develops sequentially.
The observed phenomenon is probably due to the fact that the bulk of the development of the larvae takes place in time, quickly drying up reservoirs. By the time of egg laying, hatching Xia generation reservoirs have dried up or were close to it, which probably led to the development of electoral taxis. Females lay eggs in the water's edge or on a wet surface areas are subject to periodic flooding. Laying on the water, followed by hatching would constitute such a biological dead end. On wet soil is completely dry to the period they occur embryonic diapause, during which clutches are dry and thorough exposure to high summer temperatures, which due to strong heating of the soil grow large quantities (up to 50 °). Adaptation to such influences was the development xerothermic properties in the egg stage. Hereditary entrenched, these qualities combined with a period of diapauzirovaniya guarantee the safety population in any climatic irregularities. However, under favorable conditions, a continuous hatching, which reflects the overall trend of increasing the capacity of the biological species.
Under natural conditions, it is shown as follows. In the temperate zone of the USSR, and in the arid zones of Kazakhstan tightening spring development and dedicated it to the re-flooding of water are due to the fact that in the period between the two flooding overwintering eggs have xerothermic impact. In more southern regions of Kazakhstan, the passage of this period is a warm, dry autumn and therefore part of the diapause larvae hatching eggs observed at the appropriate temperature during the first flood. Mass hatching of the same depends on the number of filled clutches. Typically, it is not confined to the time of minor flooding meltwater ponds, and the period of the spring flood of different rivers and associated lakes. In this case, the water level rises to an important extent, and all are filled egg.
Us, and KA Amirgazievym (1966) and VP Bozhenko (1948) in late April found a small number of larvae of this subspecies in time, well-warmed waters. Mass development of the larvae in the south, south-east and west of Kazakhstan noted in the first or second decade of May. This is, as already mentioned, with the re-flooding of the breeding grounds in the more northern parts of the vast and spring floods of the rivers in the south.
Height of the flood and thus flooded area breeding sites play for this subspecies of paramount importance. Thus, in 1962 spring flooding in May on the Syr-Darya (100 km Chardara below) has been modest, and the number of breeding sites of mosquitoes insignificant. The following year, the water level went up a lot, the area of temporary ponds has increased by 7-8 times and the number of developing larvae increased to 17 thousand for 1 m2. A similar phenomenon was noted in the pool or in 1963 and 1964. Explained by layering it clutches in the profile of the reservoir.
First, the most numerous of masonry made in the period of a rather large water level to higher tiers, the next – in the low-lying areas of the reservoir drying up and the last, small in number – only the bottom of a dried-up pond wet. Therefore the number of hatching the next generation depends on the water level and the subsequent flooding of the area.
As the result of the continuous hatching egg laying near the water's edge is limited, the number of subsequent generations and their number is determined by the frequency and height of future spills. In the south, south-east and west of Kazakhstan, as a rule, is another generation of this species due to the summer floods of the rivers of desert winds and surges on the northern coast of the Caspian Sea. In years with a number of minor floods first generation is negligible, and the hatching of the second is not marked at all.
In northern Kazakhstan last larval stages are found in early July in ponds dried up after the spring snow melt and rain waters flooded again. The development of the second generation was noted in late July – early August (Prygunova, 1966).
In the south of the Altai larvae last stages caught in mid-July at the height of 1300-1400 m n. a. m in a time open water formed Zatoka thawed water. Because at that height is the first flood, then only assume that hatching occurred from last year's clutch, which has experienced the effect of temperature and dryness last summer.
Seasonal variation in the number of the rest of the Kazakhstan match phenology larvae. In the south, south-east and west of the country a small number of breeding adults can be detected in early May. The main hatching occurs in late May – early June (depending on climatic conditions). The number of mosquito breeding sites can reach huge numbers. May 21, 1963, in the floodplain of the Syr Darya in 100 strokes butterfly net in the twilight were captured 3275 copies. Subsequent hatching usually observed in late July – early August, not so many, and depending on the hydrological regime is subject to large fluctuations. During the warm and rainy summer in numbers attackers this species occupies the third place after Ae. with. caspius and Cx. modestus, and at certain times even dominant over them. At such time, the activity of females due to close in time of two breeding remains high from June to mid-August. Last specimen caught in late August – early September.
In northern Kazakhstan first winged individuals appear at the beginning of July. The number of first-generation low. Hatching of the second generation, which is numerically superior to the first 12 times, celebrated in early August, and the maximum years – in the third week of this month (Prygunova, 1966). As described seasonal activity of the species in mountainous parts of the pool or at 2000 m n. a. m
Duration exceeds that of predimaginalnogo Ae. with. caspius. At 16-17 ° development is delayed up to 34 days (Shlenova, 1952). In Kazakhstan, at 23-29 ° it ends in 15-16 days. The same time spent preimago-tional development in the wild Volga delta (Monchad-sky, 1956). Gonotrophic cycle at 23-29 ° lasts 4-6 days. Number of laid by in vitro eggs less than 120, but more often in the range of 50-60 pieces. During embryonic development at 23-29E lasts 8-9 days. When tested for salt-vyplazhivanie and further development of the larvae occurred only in 1-2% solution of NaCl. Perhaps this and the features of egg laying near the water's edge, the level of which always rises upon receipt of fresh water, which prevents the egg from getting into a large salt concentration.
We swarming noted only in the evening, although Monchadsky A. (1951) observed it in the morning. Place swarming often are exposed among the thickets, and a guide – cartway or no noticeable thing. Mosquitoes swirling in countless numbers on the height of 1.5-2 m Among the majority of males and females Ae. v. vexans there are isolated instances Ae. with. caspius. Like all other members of the genus Aedes, this species overwinters in the egg stage.
The diurnal variation of activity corresponds to the usual one. The bulk of the attackers have to morning and evening hours. Morning peak period begins at dawn and ends at 1 – 1.5 hour after sunrise. Evening peak starts 45-90.chin before sunset and lasts until deep twilight. In the bright moonlight activity decreases, but does not stop completely. The greatest female aggressiveness often before sunrise and just after it. In the daytime, only attack in the bush and then in small quantities. Away from the breeding sites and dense shelters do not fly away.
Dnevok places are various herbal and natural bush shelter (caves, crevices in the rocks, wells). Petrischeva PA (1962) displayed a female boar in shelters and gazelles, burrows of badgers, wolves, jackals, steppe cats, porcupines, gerbils, squirrels, hamsters, rats, hedgehogs, Shchurok nests, owls, swifts and swallows, we to same – in the nests of crows.
Subspecies prefers wild and domestic animals, but willingly striker and a person. Often flies into villages. Most attacks on pets.
Possible vectors of the virus St. Louis encephalitis, western and eastern equine encephalomyelitis, lymphocytic chorio-meningitis (Chamberlain, 1958; Gluschenko Gutsevich, Dudkina, 1957). In Kazakhstan Ae. vexans was able to transmit the agent of tularemia (Olsufiev, 1938).