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I see climate change being blamed for this increase in insect bites, but can this be right? Perhaps it’s a factor; however, as I understand it the USA has warme

by todd8 8y ago

I see climate change being blamed for this increase in insect bites, but can this be right? Perhaps it’s a factor; however, as I understand it the USA has warmed by about 1.4 degrees Fahrenheit over the last 100 years[1]. There is roughly a 50 degree difference between the northern states (excluding Alaska and Hawaii) and the southern states based on a quick peek at iso therm maps for the USA.[2] It lookes like that would increase the ticks habitats very little over a whole century. Now take a look at the dramatic changes in just few years presented in the article. [1] https://globalclimate.ucr.edu/resources.html https://globalclimate.ucr.edu/resources.html [2] https://climate.ncsu.edu/images/edu/IsobarsIsotherms.gif https://climate.ncsu.edu/images/edu/IsobarsIsotherms.gif

phyller 8y ago
I think lately we are looking for a reason to blame climate change for a lot of things because it is top of mind and we fear it so much. However, a historically cold climate disease like Lyme disease moving south is not explained by warming temperatures. I suspect several reasons. First, an increase in the natural vectors for parasites. We have eliminated wolves and reduced other predators, and since we don't hunt small mammals for food anymore there could be an explosion in their population. Even deer, which we continue to hunt, have seen rapid population growth over the last century[1]. Looking at the population minimum from the deer population chart, I suspect that other potential disease vector hosts might have gone through a similar minimum followed by a rebound, and parasites are recovering with them. Second, an increased awareness of these diseases is probably a big factor. I've known many people who have contracted Lyme disease. It used to be a big fight to get a doctor to take the possibility seriously, even in Connecticut where I used to live (the epicenter of Lyme disease)! As of even 5 years ago friends and family of mine could not get a prescription for the required antibiotic until they had a positive test result, which is finicky and allows the disease to progress over the weeks of delay. And Lyme is an incredibly debilitating disease. Diseases like Zika that have much more subtle symptoms (except in babies) could easily go unnoticed. Finally, keep in mind that malaria, dengue fever, and yellow fever used to be common in the United States. This is a natural range for these kind of mosquito borne diseases. We used to take mosquito population control much more seriously, perhaps we have become too apathetic about it. How many people do you know that are part of the local mosquito control association? Do you make sure there is no standing water on your property? Do we spray for mosquitos any more? [1] http://www.deerfriendly.com/_/rsrc/1474256275604/decline-of-deer-populations/1450Pop.jpg?height=318&width=400 http://www.deerfriendly.com/_/rsrc/1474256275604/decline-of-...
maxerickson 8y ago
Deer ticks are adapted to northern climates and the biggest source of Lyme disease. You have to look at the impact of climate on their northern range (Which historically has been near water bodies that moderate winter temperatures). North south comparisons don't much factor into it.
stevenwoo 8y ago
I remember having concerns over finding a tick on myself in the early 90's. The doctor assuaged me at the time among other things with the fact that only a couple of states in the Northeast had to be extremely vigilant about ticks and we were in the South. Now the range for concern is much of the entire range of deer in the United States and researchers are finding it in urban areas in Western Europe. A small average change is small but it's something. There was some separate issue about saiga antelope undergoing catastrophic die off a few years ago. The best theory now is a temperature change enabling bacterial infection by bacteria that were always present but not killing the antelope. The average temperature would not change that much as per your data but the extremes are going to swing more with climate change. http://www.bbc.com/news/science-environment-42720955 http://www.bbc.com/news/science-environment-42720955
- phyller 8y ago
  How does warmer weather explain ticks moving farther south?
  - stevenwoo 8y ago
    The ticks carrying the Lyme disease bacteria were trapped in the Northeast (for the USA). Climate change changed the feeding behavior of the prey of juvenile nymph ticks, the main vector for increasing the habitat is mice not deer. The adults feed on deer but most infections in people that we know about come from nymphs ( probably because they are so tiny). A laymen's explanation: https://qz.com/441583/lyme-disease-is-spreading-faster-than-ever-and-humans-are-partly-to-blame/ https://qz.com/441583/lyme-disease-is-spreading-faster-than-... "But our rapidly changing climate also seems to be making it easier for Lyme to spread, by shifting when blacklegged ticks typically feed." This means it's simply a matter of waiting for the temperature to rise just a bit more for the Lyme disease to be a problem in the USA everywhere there are deer. There is the difficulty with temperature theory helping the spread the same way in Europe which the article covers, but Lyme disease in Europe is a slightly different bacteria as well. The National Science Foundation explanation: https://www.nsf.gov/news/special_reports/ecoinf/lyme.jsp https://www.nsf.gov/news/special_reports/ecoinf/lyme.jsp

by todd8 8y ago

phyller 8y ago

I think lately we are looking for a reason to blame climate change for a lot of things because it is top of mind and we fear it so much. However, a historically cold climate disease like Lyme disease moving south is not explained by warming temperatures. I suspect several reasons. First, an increase in the natural vectors for parasites. We have eliminated wolves and reduced other predators, and since we don't hunt small mammals for food anymore there could be an explosion in their population. Even deer, which we continue to hunt, have seen rapid population growth over the last century[1]. Looking at the population minimum from the deer population chart, I suspect that other potential disease vector hosts might have gone through a similar minimum followed by a rebound, and parasites are recovering with them. Second, an increased awareness of these diseases is probably a big factor. I've known many people who have contracted Lyme disease. It used to be a big fight to get a doctor to take the possibility seriously, even in Connecticut where I used to live (the epicenter of Lyme disease)! As of even 5 years ago friends and family of mine could not get a prescription for the required antibiotic until they had a positive test result, which is finicky and allows the disease to progress over the weeks of delay. And Lyme is an incredibly debilitating disease. Diseases like Zika that have much more subtle symptoms (except in babies) could easily go unnoticed. Finally, keep in mind that malaria, dengue fever, and yellow fever used to be common in the United States. This is a natural range for these kind of mosquito borne diseases. We used to take mosquito population control much more seriously, perhaps we have become too apathetic about it. How many people do you know that are part of the local mosquito control association? Do you make sure there is no standing water on your property? Do we spray for mosquitos any more? [1] http://www.deerfriendly.com/_/rsrc/1474256275604/decline-of-deer-populations/1450Pop.jpg?height=318&width=400 http://www.deerfriendly.com/_/rsrc/1474256275604/decline-of-...

maxerickson 8y ago

Deer ticks are adapted to northern climates and the biggest source of Lyme disease. You have to look at the impact of climate on their northern range (Which historically has been near water bodies that moderate winter temperatures). North south comparisons don't much factor into it.

stevenwoo 8y ago

I remember having concerns over finding a tick on myself in the early 90's. The doctor assuaged me at the time among other things with the fact that only a couple of states in the Northeast had to be extremely vigilant about ticks and we were in the South. Now the range for concern is much of the entire range of deer in the United States and researchers are finding it in urban areas in Western Europe. A small average change is small but it's something. There was some separate issue about saiga antelope undergoing catastrophic die off a few years ago. The best theory now is a temperature change enabling bacterial infection by bacteria that were always present but not killing the antelope. The average temperature would not change that much as per your data but the extremes are going to swing more with climate change. http://www.bbc.com/news/science-environment-42720955 http://www.bbc.com/news/science-environment-42720955

phyller 8y ago
How does warmer weather explain ticks moving farther south?
- stevenwoo 8y ago
  The ticks carrying the Lyme disease bacteria were trapped in the Northeast (for the USA). Climate change changed the feeding behavior of the prey of juvenile nymph ticks, the main vector for increasing the habitat is mice not deer. The adults feed on deer but most infections in people that we know about come from nymphs ( probably because they are so tiny). A laymen's explanation: https://qz.com/441583/lyme-disease-is-spreading-faster-than-ever-and-humans-are-partly-to-blame/ https://qz.com/441583/lyme-disease-is-spreading-faster-than-... "But our rapidly changing climate also seems to be making it easier for Lyme to spread, by shifting when blacklegged ticks typically feed." This means it's simply a matter of waiting for the temperature to rise just a bit more for the Lyme disease to be a problem in the USA everywhere there are deer. There is the difficulty with temperature theory helping the spread the same way in Europe which the article covers, but Lyme disease in Europe is a slightly different bacteria as well. The National Science Foundation explanation: https://www.nsf.gov/news/special_reports/ecoinf/lyme.jsp https://www.nsf.gov/news/special_reports/ecoinf/lyme.jsp