Largest Latrodectus?

[Scolopendra55]

What is the largest species of Latrodectus?

 

[Skypainter]

I would have to say in the USA L. hesperus is the largest. I have seen some huge ones in my dad's shop where I grew up in Hanford, CA. I swear his shop has got to have one of the largest populations of black widows in the state!

 

[buthus]

L.tadzhicus or one of those other mid-east solid black flavors.

L.mactans-mactans supposed to be as big or bigger than hesperus ...waiting...very soon I will have some in my hands ...to feed and let em get huge.

 

[Venom]

L.tadzhicus or one of those other mid-east solid black flavors.

Any proof/ documentation?


I've heard of some *very* large L.hesperus ( just ask cacoseraph ). That would really be something for an L.mactans to beat them!

 

[spydrhunter1]

I have mactans that approach the size of hesperus, but overall hesperus are larger.

 

[LongDucDong]

Ive seen some MONSTER mactans in Missouri, easily the largest Latrodectus I have seen. All the hesperus Ive seen are about the same size as mactans, but Ive seen several mactans that were just gargantuan.

 

[buthus]

Any proof/ documentation?


I've heard of some *very* large L.hesperus ( just ask cacoseraph ). That would really be something for an L.mactans to beat them!

Read something of that affect. Sorry... thought I could find that info. Couldn't ...so consider it smoke out of my arse.
Though, the subject was brought up lately in passing. Think it was splintercell that mentioned it. Maybe he can clear it up.

I've caught a few HUGE hesps this year. Never seen local widows as big. Would be interesting to try and breed them bigger!

 

[Ganoderma]

many of the L. hesperus i kept were much larger than the mactans i ever kept. The solid black l. hesperus didnt seem to grow as big as the regular ones though, not sure if it was coincidence or what.

Some of my hesperus put good sized jelly beans to shame.

 

[KUJordan]

I just got a L. hesperus from Steven the other day that would take down any other US widow, no doubt. I've had a ton of experience with mactans, and they don't hold a candle to this thing. I may even try to post some pics here soon of this beauty. I'll post her and I'll post the largest mactans I have ever seen, of which there will be no comparison.

I'm very interested to find out more about this L. tad... that Steven and Tom have mentioned.

 

[buthus]

I just got a L. hesperus from Steven the other day that would take down any other US widow, no doubt. I've had a ton of experience with mactans, and they don't hold a candle to this thing. I may even try to post some pics here soon of this beauty. I'll post her and I'll post the largest mactans I have ever seen, of which there will be no comparison.

I'm very interested to find out more about this L. tad... that Steven and Tom have mentioned.

Conjuring up an old post here...
Yep, sent you one of the 7 or 8 exceptionally huge hesps I have found this last year within my yard.
Been going out last few nights to see how some of my yard girls are handling the near to freezing (actualy did get below freezing for a couple moments). Collected a few ...just because i felt sorry for them ...its around eighty in my room! Last night I was turning over a bunch of big rocks we have piled up for future landscaping ...looking for a girl that I spotted there weeks ago. More and more webbing under each rock I removed and then under a big flat rock at the bottom of the pile... yowser...look at this BBW! Heck, she isnt even fat ....yet.
Ran and got my camera and a cordless shop light ...and a cup ...better make it 2oz.
BTW... it was 38F when I collected her. She was a bit sluggish, but still very agile and responsive.

I love a widow that knows how to fill a 2oz dixie!

Check out the girth and stretch of her front legs.

gonna fatten her up nice and get a good look at her hr glass. Whats the chances that such a pretty monster is not gravid?? It would be nice to choose her a mate!

Anyway...there you have it ...largest Latrodectus in the world!
..

 

[Brian S]

Of the US species, I would dare say that L variolus could be the largest, at least here in Missouri. We have some rather large mactans here but I have seen several variolus that are larger. This perhaps isnt true with all areas but strictly speaking with what I have observed in MO it is.

 

[Venom]

Yes, variolus is larger than mactans in general, but smaller in potential than L. hesperus--or so I've read.

 

[buthus]

I found a few big ones while out observing whats happening to the population during this cold spell. BUT...this one is exceptional... now that got another look at it...I am quite impressed!

Ill try and do some kind of comparison shots soon.

I got to find a male from the same line or a big male from a new line to mate this baby ...then again, she'll probably end up being gravid. Though I looked for sacs where she was and found none.

 

[cacoseraph]

i'll try to grab some big hesperus if i see any. i should be able to find a 2.5"DLS if i look around. there have been some so big they actually made me a little uncomfortable... if i catch a 3"DLS in the next couple years i wouldn't be *too* surprised

 

[Galapoheros]

3"DLS . The adults I see here in Tx are usually 1.5"DLS or less.

 

[buthus]

i'll try to grab some big hesperus if i see any. i should be able to find a 2.5"DLS if i look around. there have been some so big they actually made me a little uncomfortable... if i catch a 3"DLS in the next couple years i wouldn't be *too* surprised

Never seen one hit 2.5". Id love a few samples of those for my "bbw" breeding project. This ones massive...cant imagine seeing one that is bigger!

 

[orcrist]

Hmm... breeding larger latrodectus... ?

 

[acrobasis01]

Largest Latrodectus hesperus (possible Utah subspecies)

Largest Latrodectus hesperus I personally collected: body length (prosoma + opisthosoma) = 61mm (2.4 inches); leg span = 155mm (6.1 inches). Other measurements included: 1st leg length = 69mm (2.72 inches), opisthosoma (abdomen) diameter = 43mm (1.69 inches), Prosoma (cephalothorax) length = 18mm (0.71 inches), Prosoma (cephalothorax) width = 15mm (0.59 inches), Cheliceral length = 3mm, Cheliceral fang length = 1mm.

This specimen was a real monster. Sorry, no pictures. I hope to get some of really big L. hesperus on Poison Spider Mesa, in Grand County Utah, a location somewhat famous (or infamous) for extremely large black widow spiders.

I am a retired Entomologist from Texas A&M University and have seen many large Latrodectus hesperus specimens. Most were in West Texas. While working as the Pecos and Reeves County, Texas, Extension Agent - Entomology/IPM, I collected several unusually large specimens with prosomal plus opisthosomal lengths that exceeded 44mm (1.75 inches) and leg spans in excess of 100mm (4 inches). I donated them to the entomology reference collection in Pecos County Extension Office in Fort Stockton, Texas, where they still reside to the best of my knowledge.

The largest specimen (noted in first paragraph) I ever found, however, was in Payson, Utah, where I resided in 1978. I collected this black widow in June, 1978. It was a genuine monster. I found it while controlling a large population of western black widows (L. hesperus) infesting the foundation of my home. I had observed a medium sized black widow in the second story window of our nursery, less than a foot from the crib of my newborn daughter. I believed that overcrowding at ground level along the foundation had pushed the spider to the second floor. Investigation proved that I was correct. I found a window well crowded with more than 400 black widows.

To destroy as many of the black widows as I could, I applied a tank mix of chlordane (now banned), dieldrin (now banned), diazinon (now banned), and permethrin (now registered but experimental at the time). I used a 3-gallon Hudson sprayer with a hollow cone adjustable nozzle. The tank mix contained 0.5 oz of 72% chlordane EC, 0.5 oz dieldrin 4 EC, 0.5 oz diazinon AG 500, and 0.5 oz permethrin 10% EC per gallon.

I applied a narrow spray to the window well and foundation. In a week's time 1,247 medium-sized to large L. hesperus spiders crawled up the wall of my house and died. I recovered an andditional 438 from the window well. Many specimens exceeded 1 inch in combined prosomal and opisthomal length but were not large enough to merit collecting.

In the process of spraying, I overturned a hollow, wooden porch step. Inside was the largest L. hesperus I have yet to encounter. It resided with 243 other medium to large sized L. hesperus spiders. I sprayed this black widow nest with the same tank mix used to treat the foundation and window well. All the spiders died almost instantly except one extremely large female.

After more than one hour, this particular specimen appeared to be unaffected by the spary. Not desiring to have pesticide resistant black widows infesting my house, I decided to collect this particular specimen.

It was the largest black widow I had ever seen, and remains that way to this day. It is only black widow that truly frightened me. I lifted it out of the web with a shovel and placed it on my lawn. I killed it in an 8 oz mason jar with about an inch of alcohol in the bottom. The spider was so large it would not fit in any of my museum vials. So I filled the mason jar with alcolol and capped it. The legs had folded under to accomodate the large size of the spider.

The leg span was greater than the span of my fingers. The opisthosoma (abdomen) was larger than a golf ball, and the prosoma (cephalothorax) was only slightly smaller than the nail of my index finger. I took the dimensions after I was certain that the spider was dead. The following measurements show the great size of this spider:

1st leg length = 69mm (2.72 inches)

Opisthosoma (abdomen) diameter = 43mm (1.69 inches)

Prosoma (cephalothorax) length = 18mm (0.71 inches)

Prosoma (cephalothorax) width = 15mm (0.59 inches)

Cheliceral length = 3mm

Cheliceral fang length = 1mm

This truly monstrous black widow (Latrodectus hesperus) also resides in the reference collection in the Pecos County Extension Agent - Entomology office in Fort Stockton, Texas. Although the IPM Agent position was closed in Pecos County in the late 1990s, I believe the reference collection remained for use by the 4-H entomology club. This extremely large L. hesperus specimen is still in the 8-oz mason jar in which I originally collected it in 1978.

Best wishes,

Acrobasis01

 

[Venom]

Please, if you can, we would all love to see the results of a trip to that Utah location, or of unusually large specimens you find elsewhere. Photo-documentation would be wonderful! I'd love to lay my optical orbs on some 4" Latrodectus. :drool:

 

[buthus]

body length (prosoma + opisthosoma) = 61mm (2.4 inches); leg span = 155mm (6.1 inches).

Total Bullsht.