# Attack of the Oil Beetles!

**URL:** <https://boards.straightdope.com/t/attack-of-the-oil-beetles/952271>\
**Category:** Miscellaneous and Personal Stuff I Must Share\
**Created:** [October 10, 2021, 10:04pm UTC](https://boards.straightdope.com/t/attack-of-the-oil-beetles/952271 "2021-10-10T22:04:48Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![solost](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/solost/32/11776_2.png) [@solost](https://boards.straightdope.com/u/solost)\
**Post date:** [October 10, 2021, 10:04pm UTC](https://boards.straightdope.com/t/attack-of-the-oil-beetles/952271/1 "2021-10-10T22:04:49Z")

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Ha, not quite that dramatic, but in just the last few years I’ve been seeing this large black beetle (over an inch long in many cases) with a long segmented abdomen. Never saw anything like it a few years ago, which makes me wonder if it’s an invasive species or migrating to larger territory. Google gave me surprisingly little info about the little buggers, other than the basics.). They appear in very late summer or early fall, like now.

I did learn why they’re called “oil beetles”. I had initially assumed it was because they are inky black in color, dark as the darkest black.

But it’s actually because, if disturbed, they secrete a very toxic substance that looks like oil, that will cause blisters on human skin (they’re also called blister beetles for this reason). I read that eating them can actually be fatal! (Not sure what the LD50 is, but fortunately they’re not delicious looking enough to find out).

Who else has these buggers around, and anybody get blistered by their toxic oil? Stories please if you have them.

> **[Meloe](https://en.m.wikipedia.org/wiki/Meloe)**
>
> Pages for logged out editors learn more
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> 			 
> See text
> The blister beetle genus Meloe is a large, widespread group commonly referred to as oil beetles. Such a name comes from their defensive strategy; when they are threatened by collectors or predators they release oily droplets of hemolymph from their joints (legs, neck, and antennae). This fluid is bright orange and contains the chemical cantharidin, a poisonous substance. Wiping the chemical on skin can cause blistering of the skin and...

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**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\
**Post date:** [October 11, 2021, 12:03am UTC](https://boards.straightdope.com/t/attack-of-the-oil-beetles/952271/2 "2021-10-11T00:03:48Z")

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Cantharidin is the supposedly aphrodisiac chemical found in [Spanish fly](https://en.wikipedia.org/wiki/Spanish_fly), which is also a type of blister beetle. Maybe you want to take a look into the LD50 after all?

(Just kidding, please don’t ingest potentially lethal chemicals.)

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**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\
**Post date:** [October 11, 2021, 10:16am UTC](https://boards.straightdope.com/t/attack-of-the-oil-beetles/952271/3 "2021-10-11T10:16:30Z")

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I haven’t had any contact with them, but I’ve gotten a couple of bad [cases of blisters](https://en.m.wikipedia.org/wiki/Paederus_dermatitis) from rove beetles here in Taiwan. Both times, I wasn’t aware of the beetle being on me, but when I had the nasty blisters I went to see a dermatologist who diagnosed them.

It’s not fun! Be careful.

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**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\
**Post date:** [October 11, 2021, 4:25pm UTC](https://boards.straightdope.com/t/attack-of-the-oil-beetles/952271/4 "2021-10-11T16:25:26Z")

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Meh, as long as they’re flightless and have shortened elytra, I ain’t afeerd of them.

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**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\
**Post date:** [October 15, 2021, 1:25am UTC](https://boards.straightdope.com/t/attack-of-the-oil-beetles/952271/5 "2021-10-15T01:25:36Z")

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Jeebus!  
You people and your bugs.  
I won’t sleep worrying about the beetles who burn.  
(Sorry, fab four, not your kinda Beatles)