auspices of the Department of Agriculture and Water Supply, Winter Rainfall Region.
The two populations were removed from 1987 to 1989, monitored through to August
1990 and no further presence of the species was detected thereafter (Herbert and Sirgel
2001). Control techniques included manual collection of snails and baiting with
molluscicide (methaldehyde and methiocarb). Dense vegetation such as patches of
rank grass were removed using herbicide and flame throwers so that snails could be
detected more easily. The total cost of the programme was ZAR 215,000 over 3 years.
Herbert and Sirgel (2001) estimated that the Tygerberg colony initially covered
about 4 ha, and that over 22,000 snails were removed from the area; the species has
not been recorded subsequently. The eradication project was justified because no
species of Otala had ever been reliably recorded in South Africa prior to 1986, and
they were known to be invasive elsewhere. The species is not listed in NEM:BA as
either an invasive or a prohibited species in South Africa. Since this is a relatively
large (ca 35 mm diameter) polyphagous herbivore, there is a possibility it could be
re-introduced in future, either for cultivation or by accident.
22.4.2 Trogoderma granarium (Khapra Beetle)
Trogoderma granarium is a dermestid beetle that feeds on grains and is a serious
pest of stored grains such as wheat. Consumption of grain contaminated with this
species has negative consequences for human health because of the numerous body
parts and cast skins (Athanassiou et al. 2019). The first record of Khapra Beetle in
South Africa was from imported malt in Pietermaritzburg in May 1954; sporadic
records followed in disparate parts of the country until an outbreak in an intensive
agricultural area in the Northern Cape Province in 1972 (Viljoen 1990). Various
outbreaks continued during the 1990s in the Northern Cape and were dealt with by
extensive pesticide application. It is not clear from published literature which
agencies were involved in Khapra Beetle control, or what the operations cost.
According to South Africa’s National Status Report (van Wilgen and Wilson
2018) this species has been eradicated. According to the European and Mediterranean Plant Protection Organisation’s Global Database (EPPO 2019), this species is
no longer present in SA, having been recorded at three different sites up to 1972 but
failed to establish after control and quarantine measures were applied (Day and
White 2016).
22.4.3 Fruit Flies (Tephritidae) as Exemplar Invasive Insect
Species
True fruit flies (Tephritidae) have a long history of global invasions and South Africa is
no exception. Among the most widely recognised globally invasive fruit fly species are
22 Alien and Invasive Animal Control Projects
637
The two populations were removed from 1987 to 1989, monitored through to August
1990 and no further presence of the species was detected thereafter (Herbert and Sirgel
2001). Control techniques included manual collection of snails and baiting with
molluscicide (methaldehyde and methiocarb). Dense vegetation such as patches of
rank grass were removed using herbicide and flame throwers so that snails could be
detected more easily. The total cost of the programme was ZAR 215,000 over 3 years.
Herbert and Sirgel (2001) estimated that the Tygerberg colony initially covered
about 4 ha, and that over 22,000 snails were removed from the area; the species has
not been recorded subsequently. The eradication project was justified because no
species of Otala had ever been reliably recorded in South Africa prior to 1986, and
they were known to be invasive elsewhere. The species is not listed in NEM:BA as
either an invasive or a prohibited species in South Africa. Since this is a relatively
large (ca 35 mm diameter) polyphagous herbivore, there is a possibility it could be
re-introduced in future, either for cultivation or by accident.
22.4.2 Trogoderma granarium (Khapra Beetle)
Trogoderma granarium is a dermestid beetle that feeds on grains and is a serious
pest of stored grains such as wheat. Consumption of grain contaminated with this
species has negative consequences for human health because of the numerous body
parts and cast skins (Athanassiou et al. 2019). The first record of Khapra Beetle in
South Africa was from imported malt in Pietermaritzburg in May 1954; sporadic
records followed in disparate parts of the country until an outbreak in an intensive
agricultural area in the Northern Cape Province in 1972 (Viljoen 1990). Various
outbreaks continued during the 1990s in the Northern Cape and were dealt with by
extensive pesticide application. It is not clear from published literature which
agencies were involved in Khapra Beetle control, or what the operations cost.
According to South Africa’s National Status Report (van Wilgen and Wilson
2018) this species has been eradicated. According to the European and Mediterranean Plant Protection Organisation’s Global Database (EPPO 2019), this species is
no longer present in SA, having been recorded at three different sites up to 1972 but
failed to establish after control and quarantine measures were applied (Day and
White 2016).
22.4.3 Fruit Flies (Tephritidae) as Exemplar Invasive Insect
Species
True fruit flies (Tephritidae) have a long history of global invasions and South Africa is
no exception. Among the most widely recognised globally invasive fruit fly species are
22 Alien and Invasive Animal Control Projects
637