MOSQUITOES (DIPTERA:CULICIDAE) IN IRRIGATED AREAS OF SOUTHERN ALBERTA AND THEIR SEASONAL CHANGES IN ABUNDANCE AND DISTRIBUTION

1959 ◽  
Vol 37 (6) ◽  
pp. 899-912 ◽  
Author(s):  
J. A. Shemanchuk
Keyword(s):  
Management Practices ◽  
Common Species ◽  
Culex Tarsalis ◽  
Farming Practices ◽  
Irrigation Districts ◽  
Chaoborus Americanus ◽  
Southern Alberta ◽  
Culiseta Inornata ◽  
Abundance And Distribution ◽  
Trap Catches

More than 95% of the mosquitoes in southern Alberta develop in waste irrigation water. Sixteen species of four genera in the subfamily Culicinae were identified, namely, Anopheles earlei, Culex tarsalis, Culiseta inornata, Culiseta alaskaensis, Aedes vexans, A. cinereus, A. dorsalis, A. campestris, A. spencerii, A. flavescens, A. nigromaculis, A. riparius, A. sticticus, A. intrudens, A. cataphylla, A. melanimon; and two species in the subfamily Chaoborinae, namely, Chaoborus americanus and C. flavicans. Weekly index of the number of larvae and pupae as the average number per dip multiplied by the area in square yards, and total weekly trap catches of adults of the seven most common species were computed for each of three irrigation districts, representing distinctly different farming practices. Adults were more numerous in a sheltered than in an open site, the males noticeably more so than the females. Mosquitoes were more abundant in the older than in the newer irrigated districts, and improper farming and water-management practices favored increase in numbers, even in well-planned irrigation districts.

Isolation of western encephalitis virus from mosquitoes in Alberta

1968 ◽  
Vol 14 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. A. Shemanchuk ◽  
Odosca Morgante
Keyword(s):  
Encephalitis Virus ◽  
Culex Tarsalis ◽  
Aedes Vexans ◽  
Southern Alberta ◽  
Early Fall ◽  
Culiseta Inornata ◽  
Time Of Collection

Mosquitoes were collected in Alberta during the spring, summer, and early fall of 1965. Western encephalitis (WE) virus was isolated from pools collected between August 11 and August 25.Two positive pools, one of Aedes vexans (Meigen) and one of Culiseta inornata (Williston) were collected by sweep nets in irrigated areas of southern Alberta near places where horses were reported sick with WE virus. Seven other positive pools, three of C. inornata and four of Culex tarsalis Coquillett, were collected in southern Alberta from mammalian burrows, which are hibernating habitats for C. inornata, C. tarsalis, and Anopheles earlei Vargas. This indicates that C. tarsalis and C. inornata can enter hibernation infected with WE virus. None of the A. earlei pools tested were positive for WE virus.About 50% of the C. inornata and 9% of the C. tarsalis collected from mammalian burrows were blood-engorged at the time of collection. None of the A. earlei collected from mammalian burrows were blood-fed.

scholarly journals LABORATORY TRANSMISSION OF JAPANESE B ENCEPHALITIS VIRUS BY SEVEN SPECIES (THREE GENERA) OF NORTH AMERICAN MOSQUITOES

1946 ◽  
Vol 83 (3) ◽  
pp. 185-194 ◽  
Author(s):  
W. C. Reeves ◽  
W. McD. Hammon ◽  
Keyword(s):  
North America ◽  
North American ◽  
Common Species ◽  
Encephalitis Virus ◽  
Culex Tarsalis ◽  
Summary Table ◽  
Infected Female ◽  
Ability To Act ◽  
B Virus ◽  
Culiseta Inornata

In the present studies ten common species of Western North American mosquitoes have been tested for their ability to act as vectors of Japanese B encephalitis virus (see summary Table XII). The strain of Japanese B encephalitis virus which was used was adapted to direct mouse brain passage, probably a disadvantage, but no freshly isolated strain was available. Of the ten species of mosquitoes tested, seven were demonstrated to be laboratory vectors. These seven species represent three genera (Culex, Aedes, and Culiseta). In previously reported work Japanese and Russians had only incriminated five species of two genera (Aedes and Culex) (1–3). Transmission was made to mice 21 times and to a chicken once. Two attempts to infect mosquitoes from an infected chicken were unsuccessfui, but no significance is attached to so few experiments. Repeated tests for virus in the eggs, or in imagines reared from eggs of infected female mosquitoes have been negative. In this we failed to confirm results claimed by Japanese investigators (5, 6). These data, in addition to the published accounts by Japanese and Russian workers of the natural epidemiology of this disease lead us to believe that this virus might well establish itself in North America, especially if introduced in those areas where our native encephalitides are now endemic. These studies also indicate that species of mosquitoes (Culex tarsalis, Culex pipiens, See PDF for Structure Aedes dorsalis, and Culiseta inornata) now known to be fully incriminated vectors of the Western equine or St. Louis encephalitis viruses can also serve as laboratory vectors of the Japanese B virus. Methods for the effective abatement of these species should be further developed and put into practice if future epidemics of encephalitis of the Western equine, St. Louis, or Japanese B types in Western North America are to be prevented or brought under control.

Can farm-management practices reduce the impact of house mouse populations on crops in an irrigated farming system?

2004 ◽  
Vol 31 (6) ◽  
pp. 597 ◽  
Author(s):  
Peter R. Brown ◽  
Micah J. Davies ◽  
Grant R. Singleton ◽  
J. David Croft
Keyword(s):  
House Mouse ◽  
Management Practices ◽  
Farming System ◽  
Farm Management ◽  
Advisory Panel ◽  
Farming Practices ◽  
Management Actions ◽  
Winter Cereals ◽  
Significant Difference ◽  
The Impact

The impacts of a range of farm-management practices on house mouse (Mus domesticus) populations were tested in a large replicated field study in a complex irrigated farming system in southern New South Wales, Australia. An advisory panel, made up of farmers, extension officers, industry representatives and scientists developed a series of best-practice farm-management actions to minimise the impact of mice. Twelve experimental sites were split into six treated sites, where farmers were encouraged to conduct the recommended practices, and six untreated sites, where farmers conducted their normal farming practices. Mouse abundance was generally low to moderate for the 4-year project (5–60% adjusted trap success). We found significant reductions in population abundance of mice on treated sites when densities were moderate, but no differences when densities were low. Biomass of weeds and grasses around the perimeter of crops were significantly lower on treated sites because of applications of herbicide sprays and grazing by sheep. We could not detect any significant difference in mouse damage to crops between treated and untreated sites; however, levels of damage were low (<5%). Yields of winter cereals and rice crops were significantly higher on treated sites by up to 40%. An analysis of benefits and costs of conducting farming practices on treated sites compared with untreated sites showed a 2 : 1 benefit to cost ratio for winter cereals, 9 : 1 for rice and 4 : 1 for soybeans.

THE EFFECT OF SOD TYPE ON THE OCCURRENCE OF GROUND BEETLES (COLEOPTERA: CARABIDAE) IN A PEST MANAGEMENT APPLE ORCHARD

1984 ◽  
Vol 116 (2) ◽  
pp. 165-171 ◽  
Author(s):  
N. J. Holliday ◽  
E. A. C. Hagley
Keyword(s):  
Pest Management ◽  
Pitfall Trap ◽  
Common Species ◽  
Ground Beetles ◽  
Apple Orchard ◽  
Soil Samples ◽  
Soil Sampling ◽  
Pitfall Trapping ◽  
Before And After ◽  
Trap Catches

AbstractThe effects on carabids of natural, fescue, and rye sod types and of tillage were investigated in a pest management apple orchard. Carabids were sampled before and after the treatments by pitfall trapping and by two types of soil sampling. There were no significant effects of sod type on pitfall trap catches; however the abundance of all common species in soil samples was significantly affected by sod types. Usually in soil samples carabids were most abundant in natural sod and least abundant in tilled plots; numbers were intermediate in fescue and rye. Sod type did not affect structure or diversity of the carabid fauna.

Cache Valley virus: isolations from mosquitoes in Saskatchewan, 1972–1974

1979 ◽  
Vol 25 (6) ◽  
pp. 760-764 ◽  
Author(s):  
J. O. Iversen ◽  
R. J. Wagner ◽  
M. K. Leung ◽  
L. B. Hayles ◽  
J. R. McLintock
Keyword(s):  
Infection Rate ◽  
Culex Tarsalis ◽  
Cache Valley Virus ◽  
Cache Valley ◽  
Culiseta Inornata ◽  
Minimum Vector

Eighteen isolations of Cache Valley virus (Bunyaviridae) were obtained from a total of 113 694 mosquitoes collected in Saskatchewan during the summers of 1972 to 1974. Most of the isolations were from mosquitoes collected during August. Culiseta inornata, the most abundant mosquito (38% of total collected), had the highest minimum vector-infection rate (0.83 isolations per 1000 mosquitoes). The virus was also isolated from Culex tarsalis and Aedes texans. It is indicated in the isolations that the prairie grasslands of the province are enzootic for Cache Valley virus.

scholarly journals LABORATORY TRANSMISSION OF WESTERN EQUINE ENCEPHALOMYELITIS VIRUS BY MOSQUITOES OF THE GENERA CULEX AND CULISETA

1943 ◽  
Vol 78 (6) ◽  
pp. 425-434 ◽  
Author(s):  
W. McD. Hammon ◽  
W. C. Reeves
Keyword(s):  
Guinea Pig ◽  
Culex Tarsalis ◽  
Epidemiologic Evidence ◽  
Anopheles Maculipennis ◽  
Encephalomyelitis Virus ◽  
Culiseta Inornata ◽  
Western Equine Encephalomyelitis Virus ◽  
Culex Stigmatosoma ◽  
The Brain ◽  
Culiseta Incidens

1. Western equine virus has been successfully transmitted in the laboratory by 3 species of mosquitoes from 2 genera not previously reported as laboratory vectors: Culex tarsalis, Culiseta inornata, and Culiseta incidens. 2. Though transmission was not demonstrated, survival of the virus for more than a few days was shown to occur in Culex stigmatosoma and Psorophora confinnis. Possibly transmission occurred by the former. 3. In experiments with Culex tarsalis, infection of the mosquitoes occurred from feeding on an inoculated guinea pig, a duck, and virus-blood suspensions. After an incubation period of 10 to 30 days at a temperature above 25°C. these mosquitoes infected chickens and a guinea pig by their bite and virus was in turn demonstrated in the blood of the chickens and in the brain of the guinea pig. A total of 12 transmissions occurred. The fact that mosquitoes can be infected from fowl and in turn transmit to fowl, together with much other supporting data from field and laboratory, is interpreted as strengthening evidence that fowl serve as reservoirs of virus in nature. 4. Since Culex tarsalis mosquitoes have been repeatedly found infected with Western equine virus and epidemiologic evidence supports their incrimination, the vector rôle of this species is now established, and it may be regarded as fully incriminated. 5. Culiseta inornata has also been found infected in nature and now proven a laboratory vector. This species does not fit the epidemiological picture in the Yakima Valley as well as C. tarsalis, but may play an important rôle elsewhere. 6. Anopheles maculipennis freeborni and Culex pipiens found naturally infected have not transmitted the virus under laboratory conditions.

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