Loxosceles ( brown recluse spiders )

[Venom]

its been a while, sorry busy busy days
About Loxosceles venom, there are a lot in researchers who tried to find out the differences between the venom of all the species of recluse spiders.
Due the fact that the Chilean recluse spider is the largest species of recluse spider it pretty obvious that they contain a larger amout of venom, not nessacarely more toxic.
Yes I´d beleave there are some variations but in context with the damage it can cause, in my personal oppinion its the amount of venom what differentiate the dangerousness.

Sorry Laurens, but no. The study I referenced in my last post did look at the concentration of L. laeta venom, and found it to be 10 times more concentrated than L. reclusa venom. The science has been done; their venom is qualitatively different (FAR more potent!!!) than the common North American recluse varieties, as well as far more potent than L. rufescens. That difference in potency is IN ADDITION to their quantitative advantage in simply having more venom than smaller species. Remember, the venom yield of a spider is dependent on its volume, not its diameter in legspan. So, if the legspan doubles, the venom yield is eight times greater (my wife is a mathematician, and figured out the exponential increase for me. ).

All species of Loxosceles have a very tiny amount of venom in their glands and most subspecies don´t even grow big enough to posess a real danger to a human being.

Again, that simply isn't true. The study I linked to earlier showed the results of L. laeta bites, as observed in the hospitals of Santiago, Chile. The study reported a fatality rate of 3.7%, and a rate of serious blood and kidney poisoning of 15.7%. That means that ****EVEN WITH MEDICAL TREATMENT IN A HOSPITAL!!!**** Loxosceles laeta killed 1 in 27 bite victims observed in this study. However, 1 in 6 patients of L. laeta envenomation had VERY serious symptoms of systemic cytotoxicity. I think that definitely counts as a real danger to a human.

This means that your impression of L. laeta as "not necessarily more toxic" than other recluses, and that they "don't even grow big enough to possess a real danger to a human being," is simply and completely wrong. Loxosceles laeta is a large spider, far larger than the average Latrodectus, and it has a significant quantity of highly toxic venom. Your opinion isn't matching up with the science, nor with the hospital observations in its native country.

 

[The Snark]

Venom, what is missing from your data is bites per year per capita. That would put the significance in clear contrast. If you could dig up the info??

As it stands, that venom toxicity is placing Laeta up with phoneutria and venomous snakes. Far above trifles like latrodectus which has, if memory serves, 1 medically significant bite in several hundred.

 

[Laurens]

to start with the Chilean recluse, I did not ment it that way that the recluse spiders aren't getting big enough
but they can only penetrate the skin after the first 3/4 molts whats makes the adult specimens a potential threat.
As for the Chilean recluse these are the largest of there kind with a large quantity of toxine.
Im open for all kind of new information as we all need to grow in arachnology.
The documents for the chile recluse bite doesn't tell if this goes mainly about children, eldery or people with a bad health.
Based on clinical evidence in LA county there haven't been one reported bite in the last 80 years what makes it difficult to research in some locations.
you've probably heard about the pyramid method for bites ( bottem = Minor ) ( Top = serious damage ) as for the L.reclusa 90% of the bites are placed in the minor
or on partition above it ( modererate = swelling/blisters ) but most are selfhealing. The chilean relcuse does not live in close proximity to humans and that's probably
the reason why there's not much information on bite reports. Many bites are not even noticed or that minor they are not notecable for a bite rapport.
than we got the differences between fat perscentage, thin/slender people are less in danger for tissue death as the thicker ones because they got more tissue to destroy.
L.rufescens excists since 1967 probably after a misidentification It might have been there many years earlier. the mediterranean recluse is considered to have less potent venom
than the brown recluse spider but the pyramid I told about before is something to remind you cause all loxosceles species have sphingomyelinase D and no matter of the amount
its not something to neglect.

and offcourse if there are more scientific documents, place it in here as we are here to learn from eachother

 

[Venom]

Venom, what is missing from your data is bites per year per capita. That would put the significance in clear contrast. If you could dig up the info??

As it stands, that venom toxicity is placing Laeta up with phoneutria and venomous snakes. Far above trifles like latrodectus which has, if memory serves, 1 medically significant bite in several hundred.

So I have done some digging, and found this: a Google preview of a book which I really need to buy, entitled Arthropod Venoms, edited by S. Bettini. The material I have uploaded is from Chapter 11: "Venoms of Scytodidae. Genus Loxosceles," by H. Schenone and G. Suarez. In it I have found some pretty great data. As Google Books doesn't allow copy/pasting, I took some screenshots.

 

[Venom]

Hmm...my crops didn't come out too legibly. Give me a minute and I'll get more legible versions uploaded here.

 

[Venom]

These should be more legible:

 

[Venom]

This book preview has a LOT more information, but the selections I've given were the relevant portions per your question, Snark. I hope this helps?

 

[TheScorpionMan]

Bit of a nasty bite on that one

 

[Chris LXXIX]

To be honest, no. I can't speak for Loxosceles laeta but here where i live, back in the good first half of '80 (as a child, with my brother) we captured a lot, during years, in summer, of Loxosceles rufesces, without know of course, nothing about their powerful venom.
I don't find them much intriguing, except for those creepy eyes, ah ah. I think Cheiracanthium punctorium are more funny.
However, congrats for your spiders.

P.S
Obviously, while not "aggressive" spiders (they aren't a Pterinochilus murinus, at the end), their venom effects can be something terrible. A man last year lost completely a finger (amputation needed) due to a bite of Loxosceles rufesces and from what i know the South American ones are more even badass.
They are Sicariidae, and for lots of valid reasons.

 

[antinous]

Don't mean to bump up an old thread, but now that I have my own place, I'm still looking for Loxosceles sp., does anybody know where to get them/or any breeders that breed them?

 

[RebelWolf]

Cool. Nice looking recluses