Panache
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Registered: 18-10-2007
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Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
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The mathematics of insect attractants
Hating flies and mozzies at bbq's i have for years pondered why there are no commercial products that incorporate powerful insect attractants (i think
the sexual pheromones are particularly potent) that you place some distance away from your social/bbq setting that would drive all the insects away
from you.
All commercial products involve repellants. Mathematically it is easy to see why repellants are effective. The repellant is placed closest to the
center of area of required effect and its efficacy would decay off in some parabolic fashion from it. My experience is that although flies and
mosiquitio's generally do not land on the repellant, the efficacy has decayed off to almost nothing by the edge of the table if the repellant is in
the middle.
So thinking about the mathematics of an attractant placed a distance away from your bbq. Firstly would it simply just shift populations of insects
toward the attractant, hence resulting in no net reduction in insect populations over your social area. If this were the case then encircling your
bbq/social/picnic area with attractant would result in a ring of swarming high density insect population that decay's to almost nothing at the center
of the area (ie the picnic/bbq). THIS WOULD BE GOOD!!!
Any wind is obviously gonna fuck things up.
Bah can someone from Mortein tell me i'm wasting my time.
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not_important
International Hazard
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Problem is that you are also generating attractants - H2O, CO2, NH3, warmth. So what you need is the outer ring of attractants (catalytic
propane/butane burners), the an inner cluster of repellant.
BTW - most repellents work by 'jamming' the insects chemosensors, so it can no longer sense the gradients in CO2 or whatever; this reduces its search
for prey to the classic drunkards walk - it still may encounter you by chance.
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JohnWW
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Registered: 27-7-2004
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I would sure like to know of any good and cheap insect repellants or pheromones. It is high summer here in New Zealand now, and blowflies by day and
mosquitos by night are a terrible problem in my area. The mosquito repellants sold here, containing substances like picaridin, are grossly overpriced.
I wonder what happened to good old dimethyl phthalate (DIMP). There is a commercial repellant still sold here with the brand-name DIMP, but it now
contains no dimethyl phthalate at all, and its price is exorbitant! Does anyone know of any good sources of dimethyl phthalate?
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Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
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Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
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probably bioaccumulates like dioctylphlathhate
i think they ended-up establishing quite definitively di-octyl phlalate bioaccumulated through the food chain and manifested in weak egg shells in
avarian populations hence decreasing their reproduction rates.
Been sometime since i've been involved in plasticisers. Di-octyl phlathate is the 'new car smell and was used extensively as a plasticiser or
softener.It tended to leach out of the polmyers it was used in. it used to be a great liquid to use as a vapour trap.
So imagine dimethyl would play the same game, never knew it was a repellant though.
Interesting that insects run along a CO2 gradient i always assumed it was heat/IR for mozzies. I remember reading how they understood the chemical
signiature that ants followed along their paths but they could never figure out how the ants perceived which direction was the colony ad which
direction was the food. There were some robotics dudes in my building who were building a robot ant that followed a scent. They had funny stories.
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JohnWW
International Hazard
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Registered: 27-7-2004
Location: New Zealand
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I remember reading a few years ago that scientists had finally isolated the substance in human sweat that attracts mosquitos. I think it was a
branched-chain alcohol, possibly something like n-octan-2-ol.
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