I get the sense that someone has confused boric acid with diatomaceous earth, and spread their confusion to Wikipedia.

For an insect with a waxy cuticle over their exoskeleton, walking over diatomaceous earth is basically like John McClane in Die Hard, running in bare feet over broken glass. Except instead of bleeding to death from the lacerations, the water in their hemolymph diffuses out at a faster rate through the scratches in their cuticle, and they dehydrate to death. The glasslike skeletons of diatoms are hard, sharp, and insoluble in water at neutral pH.

Boric acid has to be ingested. It's a chemical poison. It works fine when added to bait. Sprinkling it as a powder won't work as well, as the insect would have to be dusted with it over their body, and then groom themselves shortly thereafter to remove the powder. Walking through it just dusts the ends of the legs. It works especially well with ants, who will carry poisoned baits back to the colony, but only if you add it to sugar or peanut butter.

As boric acid is softer than glass, and soluble in water, I wouldn't count on it as an insect-killing abrasive.

We can all blame Wikipedia user Rfc1394, who added the text to the Boric Acid article at 10:05, 23 June 2017, apparently with a citation to the EPA R.E.D. factsheet, which does not contain anything remotely close to the text added.

After talking with another user, it's become clear that yes you are mistaken. Your confusion about the wikipedia source led you down an incorrect path. I shouldn't have taken your statements at face value as true. You are ironically the problem you were attempting to point out -- being confused about a source, and then spreading that confusion.

First: The wikipedia source (EPA R.E.D. factsheet) you said didn't "contain anything remotely close to the text" actually does.

>Pesticide products containing boric acid and its sodium salts are registered in the U.S. for use as insecticides, fungicides and herbicides. As insecticides, some act as stomach poisons in ants, cockroaches, silverfishand termites, while others abrade the exoskeletons of insects. [0]

Second: Boric acid has a hardness of 3 not 1 as you claimed. Diatomaceous Earth has a hardness of 1-1.5. [1] [2] This just about blows a hole in every point you've yet tried to make.

I know I won't get an apology, or probably even a concession of your error, but I am posting this reply for posterity -- so other's aren't mislead.

[0] https://web.archive.org/web/20080406065032/http://www.epa.go... -- the wiki source that was incorrectly identified as not supporting the claim

[1] http://www.americanborate.com/all-about-borates/borate-appli... -- another source about the abrasive properties + boric acid hardness

[2] https://www.tedpella.com/company_html/hardness.htm -- boric acid hardness

Is it possible that the statement is about a pesticide product containing boric acid or a sodium salt of boric acid, and that the abrasive element in said product is not the boric acid?

Boric acid, or B(OH)3, is the mineral sassolite, and has Mohs hardness 1. [0]

Boric anhydride, or B2O3, has a Mohs hardness of 4. [1] It is not boric acid. It converts to boric acid in the presence of water, and is hygroscopic, so will also do so in the presence of humidity.

Borax, or Na2B4O5(OH)4•8(H2O), has a Mohs hardness of 2-2.5 . It is not boric acid. It converts to boric acid in the presence of strong acid, and is considered a hydrated sodium salt of boric acid.

Diatomaceous earth is a sedimentary material, not a pure mineral. It has components of different hardness, the relevant factor being the crushed frustules of ancient diatoms, or diatomaceous silica. "The ultimate hardness of the diatom skeleton is between 4.5 and 5 on the Mohs' scale.... The friability, or the propensity of the skeleton to break down, rather than to abrade, renders a measurement of hardness meaningless without also a consideration of the particle size." [3]

The "not even close" text was the actually quoted text "the gift that keeps on killing". Quoted from the cited source? No. The other dubious hyperbolic phrase was "the effect is like shards of glass cutting them apart", which also does not appear in the cited source. "Shards of glass" does bring to mind a broken diatom frustule, which is literally a shard of sharp silica when viewed under a microscope. There's quite a step up in intensity from "related chemicals may be abrasive" to "this exact chemical is like sharp shards of glass".

Your sources are a company that sells microscopes and "about us" copy for a company that sells mineral borates. I'm not certain what borate it has with a Mohs hardness of 3, but that means it can scratch a fingernail. Try it at home. Grow the biggest boric acid crystal you can, and then try to scratch your fingernail with it. About the only thing holding it together as a solid at all is hydrogen bonding and van der Waals forces. There is nothing there chemically to give it hardness. Individual molecules flake off readily.

So no, I will not apologize or concede.

[0] http://webmineral.com/data/Sassolite.shtml

[1] https://pubchem.ncbi.nlm.nih.gov/compound/boric%20anhydride#...

[2] http://webmineral.com/data/Borax.shtml

[3] https://www3.epa.gov/ttn/chief/old/ap42/ch11/s22/reference/r...

I think you're mistaken. There are many other independent sources that talk about its action as an abrasive. You may be the one spreading confusion.

Here's one of many. This one is from the National Pesticide Information Center which operates out of Oregon State University in partnership with the EPA (OSU has a large focus on agricultural research.)

> It can also scratch and damage the exterior of insects.

http://npic.orst.edu/factsheets/boricgen.html

I'd take a source that has been peer-reviewed by entomologists containing the evidence of independently repeatable measurements.

The falsifiable hypothesis is that crystalline boric acid can kill an insect without being ingested, by a purely mechanical action.

Sassolite (boric acid) has a Mohs hardness of ONE. Please understand why I might be skeptical of its supposed reputation for killing things by scratching them. Minerals with low Mohs hardness, like graphite, talc, and yes, also boric acid, are used as lubricants.[0]

I also question whether those multiple sources in support are truly independent, as I have seen several search results that quote the Wikipedia article verbatim.

[0] http://nersp.nerdc.ufl.edu/~wsawyer/boricWear2006.PDF

You think the EPA, the University of Oregon, and the National Pesticide Information Center are wrong?

Seems likely. Rather, they stated that 'fact' without anything more than anecdotal evidence.

This paper investigates a far more likely method of action: http://zero.sci-hub.tw/673/f8d7a6469e96789d8c958eb3c4efdc46/...

You're flat wrong.

I didn't bother checking the other claims that logfromblammo made before my previous comments, I accepted them at face value, but I did this time; Boric acid has a hardness of 3 not 1 as he claimed. Diatomaceous Earth has a hardness of 1-1.5. [0][1]

I looked at the source for the wikipedia claim that logfromblammo described so: "which does not contain anything remotely close to the text added". The source does support the claim in wikipedia. [2]

>Pesticide products containing boric acid and its sodium salts are registered in the U.S. for use as insecticides, fungicides and herbicides. As insecticides, some act as stomach poisons in ants, cockroaches, silverfishand termites, while others abrade the exoskeletons of insects.

The foundational premise behind his original post "unsourced wikipedia edit mislead other websites" is flat wrong. And on top of that, his reasoning for why boric acid wouldn't be a good abrasive "mohs hardness of 1" is also wrong, and egregiously so when the infamous Diatomaceous Earth that he claims is being mistaken for boric acid has a mohs hardness of 1-1.5! It's an irrelevant argument.

My initial diagnosis of logfromblammo being the one who was confused was absolutely correct. Very disappointed in both of you. Hopefully many people weren't mislead by being convinced by logfromblammo as you were.

[0] http://www.americanborate.com/all-about-borates/borate-appli... -- another source about the abrasive properties + boric acid hardness

[1] https://www.tedpella.com/company_html/hardness.htm -- boric acid hardness

[2] https://web.archive.org/web/20080406065032/http://www.epa.go... -- the wiki source that was incorrectly identified as not supporting the claim

I think they are referring to pesticides that contain boron, and not specifically to the individual chemical component B(OH)3 (s), a.k.a. solid boric acid.

I can easily imagine a commercial pesticide targeted at ants and roaches that contains borates, sugar, and diatomaceous earth, because that is exactly what I use in my own kitchen, made from the individual components. It is effective, and has low toxicity to humans and pets. But to be clear, it is abrasive because the D.E. component is abrasive, not from the boric acid.

D.E. is actually the only powdered pesticidal substance I am aware of that kills via mechanical means.

> How can they develop a resistance to something that physically destroys their exoskeleton? It acts as an abrasive.

Broadly speaking, couldn't they just develop a change to the structure of their exoskeleton? I can see how it might be less likely than a chemical resistance, but it still seems possible.

I'm sure it's possible, but it's like a human being developing a resistance to a hammer to the skull. It would take much more than few generations of selective pressure to do that.

Your skull IS such an adaptation. Not hammer, but it does protect your CNS from many physical harms, and was evolutionarily gifted to you back in the days of early vertebrates

I'm not saying it's not an adaptation. Think about the scale of time you just referenced and compare it to the frame of time of the study and my comment.

Read my comment again.

Thank you.

The speed of evolution is mainly a function of the length of a generation (and also of the amount of pressure from the environment). Consider how long human generations are compared to cockroaches, and how little evolutionary pressure humans face today. Read my comment again. Thank you

I did read your comment. You're wrong. A few generations (1.5 years) would not plausibly have this effect. I doubt even a hundred generations would be able to select for something so significant since it's a weakness that all exoskeleton insects have. Insects have remained largely the same for millions of years.

I never said it wasn't possible, I said it wasn't plausible for it happen on short scales of time such as this study.

You're being pedantic, but you're still wrong.

Different humans have skulls of different thicknesses and if there was a situation where hammer skullings became major cause of death I'm sure that over time those with thicker skulls or other features that made them less susceptible to skullings would survive and flourish.

how many generations will roaches have passed through within the space of one year? tens? hundreds? thousands?

American cockroaches take 6 months to a year to reach reproductive maturity