the Mediterranean Fruit Fly (Ceratitis capitata) and the Oriental Fruit Fly (Bactrocera
dorsalis). Fruit flies have a range of impacts from direct (e.g. fruit damage) to indirect,
including restricting international market access and having knock-on socio-economic
impacts, especially in Africa where small-scale farmers may be heavily reliant on fruit
or commodity sales and trade. In South Africa, the Mediterranean Fruit Fly has long
been the focus of pest management strategies, despite this region likely forming part of
its historical native distribution. Although not classified as invasive within South Africa
(Richardson et al. 2011; Karsten et al. 2015), the Mediterranean Fruit Fly is managed in
South Africa as an agricultural pest and elsewhere (e.g. Europe) as an invasive and an
agricultural pest (Karsten et al. 2018).
On the African continent, there is also a growing threat of pest and invasive fruit
fly species that readily establish and can affect agricultural food security.
South Africa is a signatory of the International Plant Protection Convention
(IPPC), an agreement between 182 countries worldwide to protect cultivated and
wild plants against invasive pest species. Trapping protocols for fruit fly detection at
borders and in commercial fruit growing areas were established in South Africa in
2006 as part of a National Exotic Fruit Fly Action Plan (Barnes and Venter 2006).
Several species in particular are being closely-monitored [including B. dorsalis,
B. zonata and Zeugodacus (Bactrocera) cucurbitae] due to concerns surrounding
their rapid spread across the African continent from their Asian origins. From its
2003 detection on the continent (Mwatawala et al. 2004; Drew et al. 2005),
B. dorsalis was found at the northern South African border in 2007/2008, and
only properly tackled in 2010 when detected again after no individuals were detected
in 2009 (Manrakhan et al. 2009, 2011). However, in the previous year a steering
committee involving industry partners and government was formed to address the
growing threat of B. dorsalis to the South African food economy (Manrakhan et al.
2009). The detection of a confirmed B. dorsalis specimen in a trap precipitated the
prescribed eradication plan. In short, a quarantine area (a circle about 80 m
2 ) would
be constructed around this point and a delimiting survey initiated (Manrakhan et al.
2012). Eradication efforts were then undertaken and included orchard sanitation (all
fruit collected is buried 50 cm below ground), Male Annihilation Technique
(400 blocks per km
2 ) as well as protein bait sprays (Manrakhan et al. 2012). If,
after 12 weeks, no further flies are detected, eradication is assumed to be successful,
quarantine lifted and ‘pest free’ status assigned, which was the case here.
However, eventually B. dorsalis was detected in multiple new and previously
eradicated areas and is currently established in several fruit-growing regions of
South Africa (Mpumalanga, KwaZulu-Natal, Limpopo, North-West and Gauteng
Provinces) (Manrakhan et al. 2015; Karsten et al. 2018), indicating failure of the
eradication attempts. The current consensus aim is to manage the invasive species
alongside the other pest fruit flies, and to employ a broader range of methods based
on integrated pest management (IPM), for example various combinations of attractand-kill, classical biological control, introduction of natural enemies, and pesticide
applications, if necessary. Although a sterile insect technique (SIT) is currently
employed for the Mediterranean Fruit Fly (C. capitata) in parts of the Western
Cape Province (Barnes and Venter 2006), as yet there are no plans, to our
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S. J. Davies et al.
dorsalis). Fruit flies have a range of impacts from direct (e.g. fruit damage) to indirect,
including restricting international market access and having knock-on socio-economic
impacts, especially in Africa where small-scale farmers may be heavily reliant on fruit
or commodity sales and trade. In South Africa, the Mediterranean Fruit Fly has long
been the focus of pest management strategies, despite this region likely forming part of
its historical native distribution. Although not classified as invasive within South Africa
(Richardson et al. 2011; Karsten et al. 2015), the Mediterranean Fruit Fly is managed in
South Africa as an agricultural pest and elsewhere (e.g. Europe) as an invasive and an
agricultural pest (Karsten et al. 2018).
On the African continent, there is also a growing threat of pest and invasive fruit
fly species that readily establish and can affect agricultural food security.
South Africa is a signatory of the International Plant Protection Convention
(IPPC), an agreement between 182 countries worldwide to protect cultivated and
wild plants against invasive pest species. Trapping protocols for fruit fly detection at
borders and in commercial fruit growing areas were established in South Africa in
2006 as part of a National Exotic Fruit Fly Action Plan (Barnes and Venter 2006).
Several species in particular are being closely-monitored [including B. dorsalis,
B. zonata and Zeugodacus (Bactrocera) cucurbitae] due to concerns surrounding
their rapid spread across the African continent from their Asian origins. From its
2003 detection on the continent (Mwatawala et al. 2004; Drew et al. 2005),
B. dorsalis was found at the northern South African border in 2007/2008, and
only properly tackled in 2010 when detected again after no individuals were detected
in 2009 (Manrakhan et al. 2009, 2011). However, in the previous year a steering
committee involving industry partners and government was formed to address the
growing threat of B. dorsalis to the South African food economy (Manrakhan et al.
2009). The detection of a confirmed B. dorsalis specimen in a trap precipitated the
prescribed eradication plan. In short, a quarantine area (a circle about 80 m
2 ) would
be constructed around this point and a delimiting survey initiated (Manrakhan et al.
2012). Eradication efforts were then undertaken and included orchard sanitation (all
fruit collected is buried 50 cm below ground), Male Annihilation Technique
(400 blocks per km
2 ) as well as protein bait sprays (Manrakhan et al. 2012). If,
after 12 weeks, no further flies are detected, eradication is assumed to be successful,
quarantine lifted and ‘pest free’ status assigned, which was the case here.
However, eventually B. dorsalis was detected in multiple new and previously
eradicated areas and is currently established in several fruit-growing regions of
South Africa (Mpumalanga, KwaZulu-Natal, Limpopo, North-West and Gauteng
Provinces) (Manrakhan et al. 2015; Karsten et al. 2018), indicating failure of the
eradication attempts. The current consensus aim is to manage the invasive species
alongside the other pest fruit flies, and to employ a broader range of methods based
on integrated pest management (IPM), for example various combinations of attractand-kill, classical biological control, introduction of natural enemies, and pesticide
applications, if necessary. Although a sterile insect technique (SIT) is currently
employed for the Mediterranean Fruit Fly (C. capitata) in parts of the Western
Cape Province (Barnes and Venter 2006), as yet there are no plans, to our
638
S. J. Davies et al.