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Welcome to my site on photography, ecology and general geekdom.

European bumblebees finding success in Patagonia

European bumblebees finding success in Patagonia

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It has at times been common practice to introduce species to a new area. Generally to remove pests or enhance production in some way. In the 80s and 90s European bumble bees were transported to South American, Patagonia to be precise, in order to aid with pollination of crops. Well used bee populations can increase the economic benefits of crops significantly. but it seems that the bees are doing just a little too well. Reports from a serious of surveys conducted between 2004 and 2012 shows an increasing spread of Bombus terrestris and Bombus ruderatus across the region.B. ruderatus were collected from colonies in New Zealand where it had previously been introduced in the 19th century and B. terrestris are thought to have been collected from Mt. Carmel region of Israel and introduced in 1998 to Chile. Since their introduction they have both thrived in their new environment, with B. terrestris in particular making a significant invasion effort. While B. ruderatus has seemingly entrenched itself in Chile and the east side of the Andes B. terrestris has now reached the Atlantic coast near Comodoro Rivadavia. It has completely replaced the native Bombus dahlbomii and has become the dominant species everywhere it has spread. Even B. ruderatus numbers have declined once B. terrestris arrived in locations they were more dominant.They don’t appear to be spreading alone though, parasites have gone with them. Most notably Crithidia bombi, thought to have been brought across with B. ruderatus, are using their primary hosts B. terrestris to great success since their introduction.It is not entirely understood what is causing the native population of B. dahlbomii to retreat so drastically in the face of the invaders, it is possible that the parasites are having a significant effect but this is hard to prove. It is also possible that B. terrestris are just merely out competing the indigenous species for resources but this is also thought to be unlikely. Whatever the case there is a serious issue pertaining to the introduction of these species which look likely to continue their expansion throughout South America.There is a history of bad consequences resulting from introducing species into a new environment for one reason or another. The cane toad was introduced to many places in order to control pests, but its voracious appetite for anything it could eat and the success at which it managed it saw them becoming the pests they were meant to destroy. Another story is of rabbits in Australia, among many others, they may all have started out with good intentions but a lack of foresight has seen greater problems emerging in many places.Reference:Schmid-Hempel, R, Eckhardt, M, Goulson, D, Heinzmann, D, Lange, C, Plischuk, S, Escudero, L, Salathé, R, Scriven, J, & Schmid-Hempel, P 2014, 'The invasion of southern South America by imported bumblebees and associated parasites', Journal Of Animal Ecology, 83, 4, pp. 823-837

Rabbits, pets or pests

Rabbits, pets or pests

The devil is in the genes…