Wikipedia:Reference desk/Archives/Science/2022 May 24

= May 24 =

Do Mossad issue their agents with Desert Eagle pistols?
I was told this recently, but I had a search around and I can't confirm this.

Was under the impression that most Desert Eagle pistols, despite their reputation, were owned by private citizens and used for shooting targets or tin cans, or maybe for defense of a home, gas station or liquor store in the USA. And that the military/mumblemumblesomething ops groups had no use for them at all in reality. Anyone know? --146.200.128.101 (talk) 04:29, 24 May 2022 (UTC)
 * The Desert Eagle is listed as item 27 on this listing of weapons used by Mossad. The list includes past arms, so it may have been retired from active duty. --Lambiam 06:31, 24 May 2022 (UTC)

Insect fights
Somehow I was reading Wikipedia this morning and following links and I ended up on insect fights. I have a couple of questions...

- is it possible for a human to train up an insect for fighting? If so, how do they do it?

- is there some sort of 'open species kumite' where the people just find a bug somewhere that looks big and tough and enter them to fight? IOW, regardless of the species...

Not planning to do this by the way. I raced snails with my friends when I was 8, but I don't think I want to watch a ladybird fight a wasp to the death for beer money. --Iloveparrots (talk) 05:55, 24 May 2022 (UTC)


 * Fighting is their natural response to competitors, so they don't need training, but they can be stimulated to fight as described, for example, in our article on cricket fighting. Shantavira|feed me 10:50, 25 May 2022 (UTC)


 * See also Winning big in Thailand’s rhinoceros beetle matches and A Look Into The Strange World Of Japanese Beetle Fighting. Alansplodge (talk) 11:37, 26 May 2022 (UTC)

Horse lip sound
How is it that a horse can do this, but I can't? 2601:18A:C500:C00:C47:6EE2:309F:9B11 (talk) 07:35, 24 May 2022 (UTC)
 * Anatomy. 41.165.67.114 (talk) 07:52, 24 May 2022 (UTC)
 * I can smack my lips but not as loudly. A horse can do several things that you can't. But you can do loads more things that a horse can't. Shantavira|feed me 08:22, 24 May 2022 (UTC)

Can anyone identify these spiders?
My mother took these photos while out walking in Lancashire. She says the spiders were about 1½" wide. Any ideas what species they are? nagualdesign 18:27, 24 May 2022 (UTC)
 * Looks like Silkworms my friend Zindor (talk) 18:34, 24 May 2022 (UTC)
 * I've just spent some time looking online for images of silkworms and can find nothing similar. I also asked my mother if she'd just assumed they were spiders or if she saw any actual spiders (not just 'legs'). The only clue she could provide was that there were about a dozen of those bushes, all covered in the same silky things, and none of the other plants had any. Anyone know what kind of bush that is? And does that lend credence to it being a silkworm hatchery? nagualdesign 19:39, 24 May 2022 (UTC)
 * I'm inclined to think that actual silkworms, and the mulberry bushes on which they feed, are not present in Lancashire. We have List of animals that produce silk, and the answer presumably lies in that extensive list somewhere. (The list includes goats. I often wonder what happened next in that materials science story. Did they just give up, or is silk now produced this way? - "Quiet momentum continues", c. 2019.) Edit: morus (plant) says Black mulberry was imported to Britain in the 17th century in the hope that it would be useful in the cultivation of silkworms. I still think this is kind of unlikely. Card Zero  (talk) 19:50, 24 May 2022 (UTC)
 * From what I've seen, it seems like silkworm moths lay their eggs on leaves in clusters. The moths don't produce silk or protect their eggs with silk. It would also surprise me if hatchlings would spin silk around themselves, when their priority is to leave the nest and start eating as much as possible. In short, I'm not convinced that these are silkworms or spiders. nagualdesign</b></b> 19:46, 24 May 2022 (UTC)
 * I apologise for the confusion, i meant to be vague but i can see how it was taken as Bombyx mori. I saw this in Cheshire a number of years ago and looked into it, so i knew it was the caterpillar of a silk producing moth of some kind but couldn't recall which. Mike Norton's answer seems most plausible Zindor (talk) 23:04, 24 May 2022 (UTC)
 * There are several species of moths whose caterpillars can produce lots of silk. It's produced to provide protection against birds. The Bird-cherry ermine looks like a possibility. See this webpage for more general information.Mikenorton (talk) 20:16, 24 May 2022 (UTC)
 * The caterpillars in the collage look dark. The dark caterpillars creating a massive web seen in this article are said to be ermine moths. Other dark caterpillars that spin a communal web are the tent caterpillars. --Lambiam 07:21, 25 May 2022 (UTC)

Thanks for all the replies. Looking at images online, eastern tent caterpillars does appear most likely. <b style="font:1.3em/1em Trebuchet MS;letter-spacing:-0.07em"><b style="color:#000">nagual</b><b style="color:#BBA">design</b></b> 09:15, 25 May 2022 (UTC)


 * Those are native to North America, so that's unlikely. The host plant leaves look like those of a Bird cherry, see here, which fits with my original suggestion. Mikenorton (talk) 10:06, 25 May 2022 (UTC)


 * I'm not sure why everyone abandoned the spider angle so quickly. Yes, some species of caterpillars spin webs, but there are spiders that build webs that look like this, such as Funnel-web spiders or cobweb spiders.  While the most striking, the classic wheel-like webs of the Orb-weaver spiders are not the only webs out there.  -- Jayron <b style="color:#090">32</b> 17:20, 25 May 2022 (UTC)
 * I suggest they abandoned it because the caterpillars are clearly visible in the photographs. {The poster formerly known as 7.81.230.195} 90.209.235.54 (talk) 17:45, 25 May 2022 (UTC)
 * That and i'd seen the exact thing in the region before. You don't typically get funnel web spiders in North-west England, there are however some living in walls in Dover, in the far south of England, but it's far warmer there and they arrived on ships Zindor (talk) 21:06, 25 May 2022 (UTC)


 * See also https://www.eadt.co.uk/news/suffolk-caterpillar-cobwebs-taking-over-trees-8993058. --Phil Holmes (talk) 07:36, 26 May 2022 (UTC)
 * List of Theridiidae species suggests that Rugathodes sexpunctatus has been introduced to Britain, and it certainly is found in other climates akin to Lancashire. -- Jayron <b style="color:#090">32</b> 17:56, 26 May 2022 (UTC)
 * Records for that spider in Britain are very localised, found only in the Glasgow area of Scotland. Mikenorton (talk) 00:01, 27 May 2022 (UTC)