Details of this species in Argentina
Arrival Date: early 1980s
Species Notes for this Location:
V. germanica arrived in Patagonia (southern Argentina) in the early 1980s where they were first observed in the Neuqén province. (They probably arrived from Chile through the low mountain passes near Chos Malal). They are now established in various sites in Patagonia in both agricultural areas and natural environments, including nine national parks and beech forest habitats (where they are present in low densities) (Sackmann et al, in D'Adamo et al. 2002). It has been noted that human activities that fundamentally change environments may encourage wasp colonisation; in the Rio Negro valley (also in Argentina) fruit production and irrigation have made food and water resources unexpectedly plentiful for wasps and has thus favoured their establishment (D'Adamo et al. 2002).
Management Notes for this Location:
Preventative:D'Adamo and collegues (2002) predicted the potential distribution of V. germanica in Argentina. Climatic conditions in the wasps original range were compared with climatic conditions in Argentina by means of ecoclimatic matching techniques (CLIMEX). The results showed that much of Argentina does not appear to be suitable for the establishment of this species. However, the model predicts that V. germanica could reach higher densities than those presently observed in Patagonia. The model predicts that there are areas in the center of the country which favour the wasp. However the region currently invaded by the wasp is surrounded by an 'unfavourable region' band which could be the reason why the wasp has not dispersed.
Chemical:In NW Patagonia (Argentina) Sackmann et al (2001) found that beef baited with fipronil reduced wasp densities by 80-100%. Further studies by Sackmann and Corley (2007) found that the most attractive bait for V. germanica was beef. Honey and corn syrup did not attract foraging wasps as effectively, even when mixed with beef. The only effective insecticide was hydramethylnon 2% which reduced wasp populations by 54% after 72 hours. Although fipronil was more effective, the potential of insects to develop resistance to consistent use of one product may suggest the need for alternating use of insecticides in some situations (Sackmann & Corley, 2007).
Reduction in native biodiversity: The German wasp is reported to prey upon native species in Argentina (Sackmann et al., 2001).
Last Modified: 25/02/2010 2:22:13 p.m.