knowledge, to adopt a SIT program for B. dorsalis. Suckling et al. (2014) assembled
a specific database for fruit flies from the Global Eradication Database (http://b3.net.
nz/gerda/), investigating eradication and response programmes and their outcomes in
17 tephritid species worldwide. They show that for the 108 programmes targeting
13 Bactrocera species there was a 12% failure rate, compared to programmes
targeting Anastrepha or Ceratitis species included in the study with no reported
failures. Furthermore, B. dorsalis (including B. philippinensis, B. invadens and
B. papayae after synonomisation; see Schutze et al. 2015) specifically had more
official responses than any of the other Bactrocera species (n ¼ 63) with eradication
declared in 39 cases. It seems therefore that Bactrocera species may be inherently
more difficult to eradicate than Anastrepha or Ceratitis species, as failures are more
frequently reported in Bactrocera, as was the case in South Africa’s Bactrocera
eradication programme recently.
Despite best intentions, heightened awareness among the local population,
on-going surveillance and large-scale eradication efforts, B. dorsalis’ spread into
South Africa was not thwarted. The reasons for this are unclear, but there are several
possible explanations. For example, it may have been a consequence of high
propagule pressure in the form of multiple introductions from multiple smaller,
cryptic locations, combined with a large informal across-border (or within-country)
fruit trade that is typically poorly regulated. However, no studies, to our knowledge,
have examined these or alternative hypotheses. With new invasive Tephritidae
species already making an appearance at South African borders, it is time these
knowledge gaps are addressed thoroughly and the management responses carefully
monitored to learn from past mistakes. In our view, an across-border and withincountry program to restrict informal fruit movement would be worth implementing
to attempt to reduce the establishment of new invasive fruit fly species. Presently,
two international networks (Addison et al. 2016), FRUITFLYNET (South Africa,
Mozambique, Tanzania, Belgium) and the ERAfrica Fruit Fly project (South Africa,
Ivory Coast, Belgium, La Réunion) are in place and both projects aim to improve
trapping, surveillance and identification tools of Tephritidae pests in Africa.
22.4.4 Polistes dominula (European Paper Wasp)
and Vespula germanica (German Wasp)
These two species are treated together here because they are both social wasp species
that have global invasive distributions, and they have recently established invasive
populations in South Africa. Both species are spreading and are recognised as
invasive species in legislation (Category 1b invaders—RSA 2014).
Vespula germanica was first recorded in Newlands, Cape Town in 1974. For
several years the range of V. germanica seems to have remained confined to the Cape
Peninsula. However, in 2002 it was recorded in Somerset West more than 50 km from
Cape Town, and by 2003 it was being detected in Stellenbosch, Elsenburg, southern
22 Alien and Invasive Animal Control Projects
639
a specific database for fruit flies from the Global Eradication Database (http://b3.net.
nz/gerda/), investigating eradication and response programmes and their outcomes in
17 tephritid species worldwide. They show that for the 108 programmes targeting
13 Bactrocera species there was a 12% failure rate, compared to programmes
targeting Anastrepha or Ceratitis species included in the study with no reported
failures. Furthermore, B. dorsalis (including B. philippinensis, B. invadens and
B. papayae after synonomisation; see Schutze et al. 2015) specifically had more
official responses than any of the other Bactrocera species (n ¼ 63) with eradication
declared in 39 cases. It seems therefore that Bactrocera species may be inherently
more difficult to eradicate than Anastrepha or Ceratitis species, as failures are more
frequently reported in Bactrocera, as was the case in South Africa’s Bactrocera
eradication programme recently.
Despite best intentions, heightened awareness among the local population,
on-going surveillance and large-scale eradication efforts, B. dorsalis’ spread into
South Africa was not thwarted. The reasons for this are unclear, but there are several
possible explanations. For example, it may have been a consequence of high
propagule pressure in the form of multiple introductions from multiple smaller,
cryptic locations, combined with a large informal across-border (or within-country)
fruit trade that is typically poorly regulated. However, no studies, to our knowledge,
have examined these or alternative hypotheses. With new invasive Tephritidae
species already making an appearance at South African borders, it is time these
knowledge gaps are addressed thoroughly and the management responses carefully
monitored to learn from past mistakes. In our view, an across-border and withincountry program to restrict informal fruit movement would be worth implementing
to attempt to reduce the establishment of new invasive fruit fly species. Presently,
two international networks (Addison et al. 2016), FRUITFLYNET (South Africa,
Mozambique, Tanzania, Belgium) and the ERAfrica Fruit Fly project (South Africa,
Ivory Coast, Belgium, La Réunion) are in place and both projects aim to improve
trapping, surveillance and identification tools of Tephritidae pests in Africa.
22.4.4 Polistes dominula (European Paper Wasp)
and Vespula germanica (German Wasp)
These two species are treated together here because they are both social wasp species
that have global invasive distributions, and they have recently established invasive
populations in South Africa. Both species are spreading and are recognised as
invasive species in legislation (Category 1b invaders—RSA 2014).
Vespula germanica was first recorded in Newlands, Cape Town in 1974. For
several years the range of V. germanica seems to have remained confined to the Cape
Peninsula. However, in 2002 it was recorded in Somerset West more than 50 km from
Cape Town, and by 2003 it was being detected in Stellenbosch, Elsenburg, southern
22 Alien and Invasive Animal Control Projects
639