Assessing the relative culpability of Simulium (Diptera: Simuliidae) species in recent black fly outbreaks along the middle Orange River, South Africa

2014 ◽  
Vol 92 (6) ◽  
pp. 505-513 ◽  
Author(s):  
N.A. Rivers-Moore ◽  
R.W. Palmer ◽  
H.F. Dallas
Keyword(s):  
Control Programme ◽  
Weight Of Evidence ◽  
Pest Species ◽  
Flow Conditions ◽  
Black Fly ◽  
Simulium Damnosum ◽  
High Flows ◽  
Fly Control ◽  
Species Being ◽  
Management Issues

Black fly along the Orange River are major pests of livestock and labour-intensive agriculture, causing annual estimated industry losses in excess of US$30 million. The problem is attributed to winter high flows, with the main pest species being Simulium chutteri Lewis, 1965, although Simulium damnosum Theobald, 1903 and Simulium impukane de Meillon, 1936 may also be periodically problematic. During 2011, black fly outbreaks along the middle Orange River were perceived by farmers to have worsened and attributed to S. impukane. Here, we investigate the likelihood of this being the case, using a weight-of-evidence approach incorporating ecohydrological data. Results showed that it is unlikely that the 2011 outbreaks were caused by S. impukane, and more likely that the main outbreak cause remains S. chutteri. Sustained high flows and turbidity levels favour S. chutteri species over the other species of black fly, while flow conditions for a species such as S. impukane were favourable for 1% of the time only. However, during periods of lower flow and lower turbidity, other species of black fly may be favoured and contribute towards periodic outbreaks. We conclude that black fly control should focus on management issues around the control programme.

ECOLOGY OF BLACK FLIES (DIPTERA: SIMULIIDAE) OF THE SOURIS RIVER, MANITOBA AS A BASIS FOR CONTROL STRATEGY

1981 ◽  
Vol 113 (3) ◽  
pp. 223-234 ◽  
Author(s):  
A. R. Westwood ◽  
R. A. Brust
Keyword(s):  
Control Program ◽  
Abundant Species ◽  
Pest Species ◽  
Black Flies ◽  
Black Fly ◽  
Simulium Vittatum ◽  
Late Instar ◽  
Simulium Decorum ◽  
Fly Control ◽  
Wire Cage

AbstractTen species of black flies were collected from the Souris River, Manitoba between April 1977 and October 1978. Adults of Simulium luggeri Nicholson and Mickel, Simulium meridionale Riley, Simulium venustum Say, Simulium verecundum Stone and Jamnback, and Simulium johannseni johannseni (Hart) were collected feeding on livestock and humans, and are well known pest species. Simulium vittatum Zetterstedt was the most abundant species, but was not a pest on man or domestic animals. Simulium tuberosum (Lundström) and Simulium johannseni duplex Shewell and Fredeen were the least abundant species. Simulium j. johannseni, S. j. duplex, S. venustum, S. verecundum, S. tuberosum, and Cnephia dacotensis (Dyar and Shannon) appeared to be univoltine species while S. luggeri, S. meridionale, Simulium decorum Walker, and S. vittatum were multivoltine in the Souris River.An evaluation of cone, plate, rope, and wire cage sampling devices for black fly larvae and pupae indicated that cone samplers provided a more representative sample for population assessment.In a black fly control program, of the Souris River, Manitoba two separate larvicide treatments in spring may be necessary. In the case of two treatments, the first should be aimed at late instar larvae of S. j. johannseni, S. venustum, and S. verecundum. Since the majority of S. luggeri and S. meridionale would be in the egg stage at this time, a second treatment, 10–14 days later, would be necessary to control late instar larvae of these species.

scholarly journals Comparative performance of traps in catching tsetse flies (Diptera: Glossinidae) in Tanzania

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Imna I. Malele ◽  
Johnson O. Ouma ◽  
Hamisi S. Nyingilili ◽  
Winston A. Kitwika ◽  
Deusdedit J. Malulu ◽  
...  
Keyword(s):  
Glossina Pallidipes ◽  
Abundant Species ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Comparative Performance ◽  
Control Programmes ◽  
Fly Control ◽  
Tsetse Fly Control ◽  
Species Being ◽  
Biconical Traps

This study was conducted to determine the efficiency of different tsetse traps in 28 sites across Tanzania. The traps used were biconical, H, NGU, NZI, pyramidal, S3, mobile, and sticky panels. Stationary traps were deployed at a distance of 200 m apart and examined 72 h after deployment. The results showed that 117 (52.2%) out of the 224 traps deployed captured at least one Glossina species. A total of five Glossina species were captured, namely Glossina brevipalpis, Glossina pallidipes, Glossina swynnertoni, Glossina morsitans, and Glossina fuscipes martinii. Biconical traps caught tsetse flies in 27 sites, pyramidal in 26, sticky panel in 20, mobile in 19, S3 in 15, NGU in 7, H in 2 and NZI in 1. A total of 21 107 tsetse flies were trapped, with the most abundant species being G. swynnertoni (55.9%), followed by G. pallidipes (31.1%), G. fuscipes martinii (6.9%) and G. morsitans (6.0%). The least caught was G. brevipalpis (0.2%). The highest number of flies were caught by NGU traps (32.5%), followed by sticky panel (16%), mobile (15.4%), pyramidal (13.0%), biconical (11.3%) and S3 (10.2%). NZI traps managed to catch 0.9% of the total flies and H traps 0.7%. From this study, it can be concluded that the most efficient trap was NGU, followed by sticky panel and mobile, in that order. Therefore, for tsetse fly control programmes, NGU traps could be the better choice. Conversely, of the stationary traps, pyramidal and biconical traps captured tsetse flies in the majority of sites, covering all three ecosystems better than any other traps; therefore, they would be suitable for scouting for tsetse infestation in any given area, thus sparing the costs of making traps for each specific Glossina species.Keywords: tseste; traps; densties; Glossina; mobile; stationary; Tanzania

Displacements of Simulium damnosum and strategy of control against onchocerciasis

1979 ◽  
Vol 287 (1022) ◽  
pp. 277-288 ◽  
Keyword(s):  
Sensu Stricto ◽  
Control Programme ◽  
West African ◽  
Simulium Damnosum ◽  
Logistic Problem ◽  
Degree Of Control ◽  
High Degree ◽  
Onchocerciasis Control ◽  
Upper Volta ◽  
West African Savannah

Regular aerial treatment of 14000 km of watercourses has achieved and maintained, over an area of 700000 km 2 of West African savannah, a very high degree of control of the larvae of Simulium damnosum sensu stricto and S. sibanum , the vectors of onchocerciasis in this area. However, particular and relatively restricted parts of this area, mainly in northern Ivory Coast and neighbouring parts of Upper Volta, experience regular and prolonged reinvasions by parous female vectors, which have already taken bloodmeals (and many of them carrying the parasites) and arrive from unknown sources probably hundreds of kilometres away, from directions probably between southwest and north. This reinvasion, now experienced in three successive years, represents the outstanding scientific, epidemiological and logistic problem still facing the WHO Onchocerciasis Control Programme. An outline is presented of the multidisciplinary investigations being undertaken to find a solution.

scholarly journals STRATEGIE INNOVATIVE PER IL CONTROLLO DI ZANZARE, VETTORI DI ORGANISMI PATOGENI

2020 ◽  
Author(s):  
Giuliano Gasperi
Keyword(s):  
Reproductive Behaviour ◽  
Pest Species ◽  
Gene Drive ◽  
West Nile Fever ◽  
Environmentally Safe ◽  
Safe Control ◽  
Human Infections ◽  
Species Being ◽  
Harmful Species

Mosquitoes are the most dangerous insect species being the vectors of the pathogens causing the most widespread diseases as Malaria, Dengue fever, Chikungunya, West Nile fever, Yellow fever, Zika. Several species of the Anopheles, Aedes and Culex are responsable for millions of human infections causing hundreds of thousands of deaths per year. This causes dramatic socio-economic and health consequences, especially in developing countries. Harmful insects are controlled using chemical insecticides which cause insecticide resistance and environmental pollution, due to long term use. In the second half of the 20th century, new insect environmentally safe control stategies were been developed, based on the insect’s reproductive behaviour. Notably, the Sterile Insect Technique (SIT) has been successfully applied against some dipteran pest species in several regions of the World. It drived several research efforts to increase our knowledge of the biology of the harmful species. SIT improvements have been also achieved with several molecular biology approaches and transgene technologies such as the innovative RIDL, cytoplasmic incompatibility (CI) and gene drive.

FIELD EVALUATION OF THE PHOTOTOXIN, ALPHA-TERTHIENYL, FOR REDUCING LARVAL POPULATIONS OF BLACK FLIES (DIPTERA: SIMULIIDAE) AND ITS IMPACT ON DRIFT OF AQUATIC INVERTEBRATES

1991 ◽  
Vol 123 (3) ◽  
pp. 439-449 ◽  
Author(s):  
L.M. Dosdall ◽  
M.M. Galloway ◽  
J.T. Arnason ◽  
P. Morand
Keyword(s):  
Aquatic Invertebrates ◽  
Sampling Site ◽  
Field Evaluation ◽  
Post Treatment ◽  
Invertebrate Drift ◽  
Black Flies ◽  
Black Fly ◽  
Control Programs ◽  
Pre Treatment ◽  
Fly Control

AbstractThe efficacy of alpha-terthienyl (α-T) for reducing larval populations of black flies was determined in two streams in southeastern Ontario. By 24 h post-treatment, larval black fly population reductions greater than 90% resulted from exposure to calculated dosages of 0.04 and 0.10 mg-L−1 α-T emulsifiable concentrate over distances of 1.0 and 1.5 km, respectively. Significant population reductions were not observed 2.3 km downstream from injection of the 0.10 mg·L−1 dosage, probably because a marshy area upstream from this sampling site slowed the transport and enhanced photodegradation of α-T. Alpha-terthienyl initiated catastrophic drift of benthic invertebrates that was not selective for any functional feeding group. Significant increases in post-treatment drift, relative to pre-treatment densities, were observed downstream from treatment for eight of 10 taxa studied and included filter-feeders, grazers, and predators. Upstream from treatment, significant increases between sampling days were observed for only two taxa. The catastrophic and nonselective impact of α-T on invertebrate drift preclude its usefulness as an alternative to black fly larvicides used currently, although specialized applications for α-T may exist in integrated black fly control programs.

Computer modelling of the migration of Simulium damnosum sensu lato (Diptera: Simuliidae) across the Onchocerciasis Control Programme (OCP) area of West Africa

1994 ◽  
Vol 84 (3) ◽  
pp. 343-353 ◽  
Author(s):  
C.G. Johnson ◽  
R.P.C. Johnson
Keyword(s):  
Computer Modelling ◽  
Sampling Site ◽  
Control Programme ◽  
En Bloc ◽  
Factors Affecting ◽  
Simulium Damnosum ◽  
Breeding Populations ◽  
Hypothesis Model ◽  
Chi Squared ◽  
Onchocerciasis Control

AbstractThe number of wind-borne female Simulium damnosum Theobald sensu lato migrating across territory devoid of breeding populations (the Onchocerciasis Control Programme, OCP) were monitored daily at widely separated sites downwind. The seasonal curves of numbers recorded each day were remarkably similar in pattern at each site with little blurring (although numbers lessened as distance from source increased). The uniformity suggests that each daily batch of S. damnosum moved downwind en bloc with but a small proportion of laggards. To test this hypothesis, model curves were generated, with different proportions of daily laggards, from the data at each sampling site and compared by chi-squared tests with the observed curve at the next site downwind. It was found that, in general, those models that most closely resembled the downwind curves were those with the smallest proportion of laggards. Other aspects of the migration were also considered, notably the factors affecting loss of numbers as distance increased and the interaction between laggards and loss where it was shown that the greater the proportion of laggards the greater will be the daily loss.

Adsorption of DDT on Suspended Solids in River Water and its Role in Black-fly Control

Nature ◽  
1953 ◽  
Vol 171 (4355) ◽  
pp. 700-701 ◽  
Author(s):  
F. J. H. FREDEEN ◽  
A. P. ARNASON ◽  
B. BERCK
Keyword(s):  
River Water ◽  
Suspended Solids ◽  
Black Fly ◽  
Fly Control

The pattern and speed of displacement of females of Simulium damnosum Theobald s.l. (Diptera: Simuliidae) across the Onchocerciasis Control Programme area of West Africa in 1977 and 1978

1985 ◽  
Vol 75 (1) ◽  
pp. 73-92 ◽  
Author(s):  
C. G. Johnson ◽  
J. F. Walsh ◽  
J. B. Davies ◽  
S. J. Clark ◽  
J. N. Perry
Keyword(s):  
West Africa ◽  
Control Programme ◽  
The South ◽  
Wet Season ◽  
Breeding Sites ◽  
Simulium Damnosum ◽  
Biting Rate ◽  
Western Border ◽  
Alternative Sources ◽  
Onchocerciasis Control

AbstractBreeding of Simulium damnosum Theobald s.1., the vector of Onchocerca volvulus, had been eliminated by 1977 from about 654 000 km2 of the Onchocerciasis Control Programme in the Volta River Basin Area (OCP) of West Africa. Nevertheless, migrating adult females continually invaded the controlled area, being blown on the prevailing south-westerly winds from uncontrolled breeding sites beyond the south-western border of the OCP area. Graphs of numbers of females caught per man per day (the daily biting rate) throughout the wet season, March to October, at 16 sites in 1977 within the OCP controlled area were remarkably similar in pattern from site to site over a range of about 500 km downwind. In 1978, only seven sites within the OCP area were similarly monitored, and the graphs were different in pattern from those in 1977, when they each consisted of three or four well-defined waves or cycles of daily biting rate which could be easily identified and traced across country, their times of occurrence lagging increasingly as the distance of the site from the south-western border of the OCP area increased. Four methods were used to demonstrate and estimate the lag: visual comparison of seasonal graphs; comparison of the mean dates of cycles at different sites and the regression of these dates on distance from the south-western border; the dates when particular cumulative percentages of the total season's catch occurred at each site and their regression on distance; and principal coordinate analysis of the data and its relation to distance from the south-western border. Statistically significant lags were demonstrated and averaged one day for every 10–30 km from the border in 1977, which indicated an average speed of migration across country. In 1978, a rate of one day per 7–35 km was indicated. Where some graphs at outlying sites were anomalous, possible alternative sources of immigrant flies are considered. The possible behaviour of flies in causing the lag is discussed.

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