3 ms·

Biological control is important but not a panacea. Not all invasive species have predators/diseases that are effective, specific, and maintain a viable populat

by rgmerk 3y ago

Biological control is important but not a panacea. Not all invasive species have predators/diseases that are effective, specific, and maintain a viable population without human intervention. Biological control can go horribly wrong. One of the most notorious examples is the cane toad, which is in plague proportions across northern Australia.

teruakohatu 3y ago
In fairness to me I never said it was a panacea, just that mechanical removal and chemicals are not the only option. Biological control practised today is vastly different to the old days of "let's just see how it goes" and introduce a large mammals, reptiles or amphibians (see the famous Simpsons episode). Today it is a long scientific process to ensure the control measure is hyper targeted. Sometimes it works great other times it just doesn't work at all and the agent dies off, but gone of the days of a failure being an ecological disaster.
- pfdietz 3y ago
  An example of successful biological control of an invasive plant in North America is Purple Loosestrife. This otherwise attractive plant created large monotonous colonies in wetlands. Insects such as Galerucella calmariensis and Hylobius transversovittatus, which feed on the plant and keep it under control back in Eurasia, were found, evaluated, and introduced to the North America, to great effect. One sees the plant now but it's kept from running wild.
  - pfdietz 3y ago
    An even more remarkable story of biological control is the spongy moth (previously called the gypsy moth). https://biocontrol.entomology.cornell.edu/success.php https://biocontrol.entomology.cornell.edu/success.php "The tale of the gypsy moth is intriguing on several levels, including its mysterious control by a fungus (Hajek 2007). Originally brought to the US to breed with the native silkworms, the gypsy moth, Lymantria dispar L., escaped through a broken window in Medford, MA in 1868-9 and began defoliating deciduous forests and shade trees in many regions of North America. High populations of this pest are uncommon in areas where it has long been established (Europe, northern Africa and temperate Asia), but outbreaks have occurred where gypsy moth has invaded without its natural enemies. Fungal infected gypsy moths were found in Japan and brought back and released in the Boston area in 1910-11, but apparently didn’t take. By 1997, dozens of other natural enemies were also released but none provided effective control. In the late 1980s and early 1990s, scientists noticed gypsy moth cadavers hanging from trees in the northeastern forests and identified the cause as a fungal infection. This discovery renewed interest in using fungi for control. Molecular studies indicated that the infection was caused by the same species of fungus, Entomophaga maimaiga, as the one collected in Japan in the early 1900’s, but that it was not identical to that fungus or to the same species collected and released in 1985-86. When and where did it come from and how was it spread? The answer seems that it was an accidental introduction from Japan and probably occurred after 1971. Perhaps even more interesting is that fact that it has spread across the contiguous distribution of the gypsy moth in the Northeastern US. This spread is due to aerial dispersal of spores from gypsy moth larvae and perhaps to human activity, as gypsy moths are prone to move long distances on the undersides of vehicles. There is interest in using infected gypsy moth, or the fungus itself, to inoculate the leading edges of newly infested areas and prevent outbreaks of this devastating pest. However, details of the introduction and establishment of US populations of E. maimaiga remain a mystery."

by rgmerk 3y ago

teruakohatu 3y ago

In fairness to me I never said it was a panacea, just that mechanical removal and chemicals are not the only option. Biological control practised today is vastly different to the old days of "let's just see how it goes" and introduce a large mammals, reptiles or amphibians (see the famous Simpsons episode). Today it is a long scientific process to ensure the control measure is hyper targeted. Sometimes it works great other times it just doesn't work at all and the agent dies off, but gone of the days of a failure being an ecological disaster.

pfdietz 3y ago
An example of successful biological control of an invasive plant in North America is Purple Loosestrife. This otherwise attractive plant created large monotonous colonies in wetlands. Insects such as Galerucella calmariensis and Hylobius transversovittatus, which feed on the plant and keep it under control back in Eurasia, were found, evaluated, and introduced to the North America, to great effect. One sees the plant now but it's kept from running wild.
- pfdietz 3y ago
  An even more remarkable story of biological control is the spongy moth (previously called the gypsy moth). https://biocontrol.entomology.cornell.edu/success.php https://biocontrol.entomology.cornell.edu/success.php "The tale of the gypsy moth is intriguing on several levels, including its mysterious control by a fungus (Hajek 2007). Originally brought to the US to breed with the native silkworms, the gypsy moth, Lymantria dispar L., escaped through a broken window in Medford, MA in 1868-9 and began defoliating deciduous forests and shade trees in many regions of North America. High populations of this pest are uncommon in areas where it has long been established (Europe, northern Africa and temperate Asia), but outbreaks have occurred where gypsy moth has invaded without its natural enemies. Fungal infected gypsy moths were found in Japan and brought back and released in the Boston area in 1910-11, but apparently didn’t take. By 1997, dozens of other natural enemies were also released but none provided effective control. In the late 1980s and early 1990s, scientists noticed gypsy moth cadavers hanging from trees in the northeastern forests and identified the cause as a fungal infection. This discovery renewed interest in using fungi for control. Molecular studies indicated that the infection was caused by the same species of fungus, Entomophaga maimaiga, as the one collected in Japan in the early 1900’s, but that it was not identical to that fungus or to the same species collected and released in 1985-86. When and where did it come from and how was it spread? The answer seems that it was an accidental introduction from Japan and probably occurred after 1971. Perhaps even more interesting is that fact that it has spread across the contiguous distribution of the gypsy moth in the Northeastern US. This spread is due to aerial dispersal of spores from gypsy moth larvae and perhaps to human activity, as gypsy moths are prone to move long distances on the undersides of vehicles. There is interest in using infected gypsy moth, or the fungus itself, to inoculate the leading edges of newly infested areas and prevent outbreaks of this devastating pest. However, details of the introduction and establishment of US populations of E. maimaiga remain a mystery."