So. In the last few months, I've spent an awful lot of time thinking about chiggers.
As you may know already, chiggers are the juvenile stage of a mite. The adults are harmless, and not interested in animals, but in order to mature, they need delicious animal flesh. To that end, they climb up things that smell tasty, and find a pore or hair follicle to attach themselves to, and go to town.
That's an important bit. Their mouth-parts can't actually bite you. They need to use the preexisting holes in your skin to feed, which they do by injecting enzymes, and sucking out the cell soup that results. Your body produces a response to this, and that's what causes the itching. Most of the time the chigger is long gone before you will even begin to itch. Aside from the itching, they're otherwise harmless, at least here in the US. In Asia and around parts of the South Pacific you can acquire scrub typhus from chigger bites, which sounds like a pretty bad time.
I'm somewhat battle-hardened when it comes to the little guys, and the fact that I have not been without a least a dozen or so bites for the last few months hasn't been a big deal. Going through a few weeks with many hundreds of them will do that to you. I would like to offer you some advice if you live in chigger country, so that you don't have to go through that experience.
Firstly: Wear long pants. Some of my research partners disagree on this, but that's mostly meant they got chigger bites on their underwear lines, rather than on their ankles. Chiggers will climb your legs until they hit a barrier of some kind, and then look for a spot to feed. That can be your sock, or where your shoe meets your ankle, or what have you. Or it can be your underwear line. Or past it. Seems like a simple decision to me. If you're constantly moving, only in chigger territory for a short time, or outside at times they're not very active (when it's cool, wet, or very, very hot), long pants tucked into your boots may be all you need.
Showing posts with label pesticides. Show all posts
Showing posts with label pesticides. Show all posts
Thursday, August 25, 2011
Sunday, May 15, 2011
Decline by Fall (part II)
As I mentioned, here is the second half of the bumblebee paper (first half here). This section is probably more accessible, as it's a good bit less technical. A quick summary of the first half: many species of wild bumblebees are in steep decline around the world, for as yet unknown reasons. Potential sources of the decline may be parasites spread by commercially reared bees, the impact of pesticides (which are not typically lethal, but which may negatively impact colony health, and on which the research is very conflicted), and problems associated with habitat loss, foraging patterns, and when bees emerge. The second part of this paper deals with how we might move to protect wild bees.
Conservation of Bumblebees
The above factors (parasites, pesticides, habitat loss, and bee phenology) may interact in unknown ways to produce the worldwide decline of some species of bumblebees. Because these bees are important for food production purposes and the maintenance of current ecosystem structures dependent on their pollination activities, successful conservation efforts will need to mitigate as many potential negative factors acting on their populations as possible, until precise, species-specific causes can be determined, and more detailed conservation plans produced. Steps such as reducing rates of parasitic infestation in commercial bumblebees are of obvious benefit to the stakeholders, while it may be more difficult to generate interest in others, such as active management of field margins, or a return to crop rotations involving fallow periods.
Conservation of Bumblebees
The above factors (parasites, pesticides, habitat loss, and bee phenology) may interact in unknown ways to produce the worldwide decline of some species of bumblebees. Because these bees are important for food production purposes and the maintenance of current ecosystem structures dependent on their pollination activities, successful conservation efforts will need to mitigate as many potential negative factors acting on their populations as possible, until precise, species-specific causes can be determined, and more detailed conservation plans produced. Steps such as reducing rates of parasitic infestation in commercial bumblebees are of obvious benefit to the stakeholders, while it may be more difficult to generate interest in others, such as active management of field margins, or a return to crop rotations involving fallow periods.
Saturday, May 7, 2011
Decline by Fall (part 1)
I promised I was going to talk about things other than nuclear power, and lo: so it shall be written, so it shall be done. Here, I present the first half of a paper I produced earlier this year, dealing with the fate of bumblebees. I'm quite fond of the fuzzy little beasts.
Introduction
While the mainstream press has been primarily focused on the precipitous decline of European honeybees (Apis melliferra) and the emergence of Colony Collapse Disorder, wild native bees have also been suffering significant losses in numbers and range ( reviewed by Spivak et al. 2011, Williams and Osborne 2009). There are some 4,000 species of bees native to North America, including bumblebees (Bombus spp), leafcutter bees (Megachile spp), mining bees (Andrena spp), mason bees (Osmia spp), and others, many of which are important pollinators of New World crops (Spivak et al. 2011). I will focus primarily on Bombus species, as these are among the most studied of wild bees, and include species that are reared commercially worldwide for use as pollinators of plants such as tomatoes (Solanum lycopersicum) and peppers (Capsicum spp) in greenhouses.
Across North America and Europe, wild bee losses have not been consistent, and the factors causing them are uncertain. Some species appear to be more or less unaffected, while others have suffered large losses, possibly due to species-specific ecological processes (reviewed by Murray et al. 2009). Three historically common, closely related North American Bombus species (B. occidentalis, B. affinis, B. terricola) have been shown to have large reductions in their home range (23-87%) and relative abundance, while other species have remained stable in their distribution and abundance (Cameron et al. 2011).
Introduction
While the mainstream press has been primarily focused on the precipitous decline of European honeybees (Apis melliferra) and the emergence of Colony Collapse Disorder, wild native bees have also been suffering significant losses in numbers and range ( reviewed by Spivak et al. 2011, Williams and Osborne 2009). There are some 4,000 species of bees native to North America, including bumblebees (Bombus spp), leafcutter bees (Megachile spp), mining bees (Andrena spp), mason bees (Osmia spp), and others, many of which are important pollinators of New World crops (Spivak et al. 2011). I will focus primarily on Bombus species, as these are among the most studied of wild bees, and include species that are reared commercially worldwide for use as pollinators of plants such as tomatoes (Solanum lycopersicum) and peppers (Capsicum spp) in greenhouses.
Across North America and Europe, wild bee losses have not been consistent, and the factors causing them are uncertain. Some species appear to be more or less unaffected, while others have suffered large losses, possibly due to species-specific ecological processes (reviewed by Murray et al. 2009). Three historically common, closely related North American Bombus species (B. occidentalis, B. affinis, B. terricola) have been shown to have large reductions in their home range (23-87%) and relative abundance, while other species have remained stable in their distribution and abundance (Cameron et al. 2011).
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