scholarly journals Field and in vitro insecticidal efficacy of alphacypermethrin-treated high density polyethylene mesh against Culicoides biting midges in South Africa

2014 ◽  
Vol 203 (1-2) ◽  
pp. 184-188 ◽  
Author(s):  
P.C. Page ◽  
K. Labuschagne ◽  
G.J. Venter ◽  
J.P. Schoeman ◽  
A.J. Guthrie
Author(s):  
K. Labuschagne ◽  
L.J. Gerber ◽  
I. Espie ◽  
S. Carpenter

Culicoides biting midges (Diptera: Ceratopogonidae) are responsible for the transmission of a large number of pathogens to livestock and wild animals. In this study the presence of the genus, using light traps based at four different sites within the National Zoological Gardens of South Africa, was investigated during 2002-2004. In total, 37 species were recorded, including large numbers of Culicoides imicola Kieffer, 1913, which is responsible for the transmission of economically important arboviruses in South Africa, Europe, Middle and Far East. These results are discussed with reference to the wider Culicoides fauna in the Onderstepoort area of South Africa, their vector competence as well as biosecurity at the National Zoological Gardens.


2005 ◽  
Vol 75A (1) ◽  
pp. 14-22 ◽  
Author(s):  
S. SH. Homaeigohar ◽  
M. A. Shokrgozar ◽  
A. Yari Sadi ◽  
A. Khavandi ◽  
J. Javadpour ◽  
...  

2006 ◽  
Vol 309-311 ◽  
pp. 1161-1164 ◽  
Author(s):  
Miho Tanuma ◽  
Yoshikazu Kameshima ◽  
Akira Nakajima ◽  
Kiyoshi Okada ◽  
Shigeo Asai ◽  
...  

We have reported that CaSiO3 ceramics show very fast bone-like apatite formation in simulated body fluid (SBF). However, CaSiO3 ceramics have disadvantages in their mechanical properties and shapability. It is therefore more effective to develop composites of CaSiO3 particles dispersed in a matrix of polymer or metal. Such composites are usually prepared by homogeneously blending the ceramic powder with the matrix component. This method is, however, ineffective for the preparation of biocompatible polymers or metals because only the surfaces containing accidentally-exposed ceramic particles play a role in generating apatite in SBF. It is therefore necessary to add a large volume of ceramic powder and also to abrade the surface to expose more of the ceramic particles. In this study, CaSiO3/high-density polyethylene (HDPE) composites were prepared by hot-pressing to introduce surface CaSiO3 particles and their biocompatibilities were evaluated under in vitro conditions using SBF. CaSiO3 powders were spread on a HDPE plate and hot-pressed at 140oC and 4.9-14.7 MPa for 2 min. The composite sample (about 10×10×1 mm3 in size) was immersed in 30ml SBF (sample/solution ratio of 2.5 g/l) at 36.5oC. After 14 days soaking, the apatite product particles covered most of the composite surface and formed apatite layers. Bone-like apatite particles were formed only on the surface regions containing exposed CaSiO3 particles but no apatite was formed on the CaSiO3 particles buried in the HDPE matrix. The results show that this surface deposition method is very effective in developing biocompatibility in the composites using very small amounts of CaSiO3 powder (about <1 %v) compared with results reported for hydroxyapatite and AW glass-ceramic powders (requiring about 40 %v). It is also found that the inhomogeneous state of the CaSiO3 particles in the surface of the present composites strongly influences their biocompatibility. It will be necessary to improve the homogeneity of CaSiO3 dispersion in the surface of the composites to achieve a more uniform surface apatite layer.


Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1978
Author(s):  
Jumari Snyman ◽  
Gert J. Venter ◽  
Marietjie Venter

Culicoides-borne viruses such as bluetongue, African horse sickness, and Schmallenberg virus cause major economic burdens due to animal outbreaks in Africa and their emergence in Europe and Asia. However, little is known about the role of Culicoides as vectors for zoonotic arboviruses. In this study, we identify both veterinary and zoonotic arboviruses in pools of Culicoides biting midges in South Africa, during 2012–2017. Midges were collected at six surveillance sites in three provinces and screened for Alphavirs, Flavivirus, Orthobunyavirus, and Phlebovirus genera; equine encephalosis virus (EEV); and Rhaboviridae, by reverse transcription polymerase chain reaction. In total, 66/331 (minimum infection rate (MIR) = 0.4) pools tested positive for one or more arbovirus. Orthobunyaviruses, including Shuni virus (MIR = 0.1) and EEV (MIR = 0.2) were more readily detected, while only 2/66 (MIR = 0.1) Middelburg virus and 4/66 unknown Rhabdoviridae viruses (MIR = 0.0) were detected. This study suggests Culicoides as potential vectors of both veterinary and zoonotic arboviruses detected in disease outbreaks in Africa, which may contribute to the emergence of these viruses to new regions.


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