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Stokwe N.F.,Stellenbosch University | Malan A.P.,Stellenbosch University | Nguyen K.B.,University of Florida | Knoetze R.,Directorate Plant Health | Tiedt L.,North West University South Africa

During a survey for entomopathogenic nematodes in citrus orchards throughout South Africa, a new species of Steinernema was isolated from a citrus orchard on Rietkloof farm, near the town of Piketberg in the Western Cape Province, South Africa. The nematode was isolated from soil using the Galleria-baiting technique. Steinernema citrae n. sp. is characterised by the following morphological characters: third-stage infective juvenile with a body length of 754 (623-849) μm, distance from head to excretory pore of 56 (49-64) μm, tail length of 71 (63-81) μm, and ratio E value of 110 (85-132). The lateral pattern for the new species is 2, 7, 8, 6, 4, 2 and is not typical for the genus. Steinernema citrae n. sp. is closely related the feltiae-group. The body length of the IJ is close to that of S. texanum and S. weiseri, though it differs in body diam., the length of the pharynx and E%. The male of S. citrae n. sp. differs from S. feltiae in the length and shape of the spicule and body diam. Steinernema citrae n. sp. differs from all species in the feltiae-group in the morphology of the vulva, as it has a single flapped, low, epiptygma. It also differs from the most closely related species, S. feltiae, as there is no interbreeding between the two species. In addition, the new nematode differs from other species of the feltiae-group by characteristics of the ITS and D2D3 regions of its rDNA. © 2011 BRILL. Source

Manrakhan A.,Citrus Research International | Hattingh V.,Citrus Research International | Hattingh V.,Stellenbosch University | Venter J.-H.,Directorate Plant Health | And 2 more authors.
African Entomology

On 5 May 2010, Bactrocera invadens Drew, Tsuruta & White was detected in a methyl eugenol-baited surveillance trap in the northernmost part of the Limpopo Province in South Africa, an area adjacent to the Zimbabwe border. A delimiting survey was carried out to determine extent of spread in the area by trapping with both methyl eugenol and Biolure-3-component lures. A quarantine area of approximately 1100 km 2 (surrounding the area of detection) was implemented to regulate movement of host fruits. Eradication of the pest was achieved in the quarantine area through male annihilation technique (MAT) using fibreboard blocks containing methyl eugenol and malathion in combination with protein bait sprays (application of GF-120 and LokLure mixed with malathion) and orchard sanitation. Eradication measures were carried out for a period of 12 weeks. Thereafter, MAT blocks were removed and trapping continued for a period of four weeks to confirm eradication. No B. invadens was caught in the area during the four weeks after control measures had stopped. No B. invadens was captured within a period of 12 weeks (approximately three generations) after the last fly find in the area. This constitutes the first successful eradication of B. invadens from an area of incursion. Source

Manrakhan A.,Citrus Research International | Venter J.H.,Directorate Plant Health | Hattingh V.,Stellenbosch University
Biological Invasions

The discovery of the exotic fruit fly pest Bactrocera dorsalis (Diptera: Tephritidae), previously recognized as Bactrocera invadens, on the African continent in 2003 raised biosecurity concerns in South Africa where agriculture is of major socio-economic importance. This prompted the development of a nationally coordinated system to prevent introduction of this pest into the country. A steering committee was constituted to provide a platform for multi-stakeholder cooperation. A national action plan on B. dorsalis was developed. A surveillance network was initiated to provide for early detection of B. dorsalis. The first B. dorsalis eradication campaign was launched in 2010 following the detection of the pest in the northern border region of South Africa. Multiple point incursions were detected thereafter in the northern parts of the country and for the first 2 years all of these were considered successfully eradicated. However, the rate and geographic spread of incursions increased over time. In March 2013 the pest was declared present in the Vhembe district, Limpopo Province. All areas affected by B. dorsalis were placed under quarantine and eradication actions are still ongoing in areas other than the Vhembe district. The national control strategy on B. dorsalis continues to be focussed on preventing further incursions, slowing the spread of the pest and monitoring the extent of its distribution within South Africa. © 2015, Springer International Publishing Switzerland. Source

Gordon D.R.,University of Florida | Mitterdorfer B.,Biosecurity Australia | Pheloung P.C.,Khan Research Laboratories | Ansari S.,SWCA Environmental Consultants | And 16 more authors.
Plant Protection Quarterly

This paper provides guidance on how to address he 49 questions of the Australian Weed Risk Assessment (WRA) system. The WRA was developed in Australia in 1999, and has since been widely adapted for different regions. As interest in implementation and results comparison has increased, the issue of consistency in answering and scoring the questions has become important. As a result, this guidance was developed during the 2007 International WRA Workshop. Suggestions on search methods, data sources and examples are also provided. Source

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