Araneae - Science topic

Dear Emanuele,

For most established, older families, you can easily find reference in Jocqué & Dippenaar-Schoeman (2007). https://www.africamuseum.be/sites/default/files/media/docs/research/publications/rmca/online/zoology-documentation/spider-families_of_the_world.pdf

For newer families not included in their work, or subfamilies which have since been elevated, you should try to consult the works that elevated/described these families. If not present in those works, you might like to try contacting the authors of those works directly. If you get stuck with any of the newer Mygalomorphae families you can email me, I'll try to help as I've examined representatives of almost all extant families of mygalomorphs. It's also very important you check circumscriptions of any families which recently underwent extensive revisionary work.

In some taxa, it's very obvious - such as Theraphosidae where cheliceral teeth counts are included in many descriptions (thereby present), and only a handful of genera have maxillary serrula (example: Plesiophrictus), this being the exceptional character state.

Best wishes,

Danni

Spider genitalia are preferably not slide mounted as they are threedimensional and an object glass will deform and damage them, also making seeing some positions impossible. They are examined in ethanol where they can be manipulated and positioned to be viewed from various perspectives. They are stored in ethanol as well and are preferable put in a small tube together with the body of the spider.

We araneologists are blessed that we have http://wsc.nmbe.ch which contains the entire taxonomic literature on spiders freely available (requires only a free registration).

Dear Kumail,

here are some references that were helpful during my few outings into the world of spider taxonomy:

Ruiz GRS, Maddison WP. The new Andean jumping spider genus Urupuyu and its placement within a revised classification of the Amycoida (Araneae: Salticidae). Zootaxa. 2015; 4040 (3): 251–279. pmid:26624665

Ramírez MJ. The Morphology and Phylogeny of Dionychan Spiders (Araneae: Araneomorphae). Bull Am Mus Nat Hist. 2014; 390: 1–374.

Levi HW. Techniques for the study of spider genitalia. Psyche. 1965; 72: 152–158.

Martha:

Thanks Martha.

You may like to have a look at this link for identification:

Best

Syed

Dear Stefano, and dear Jens,

Perhaps I'm one of the guys who may outnumber this first interesting observation.

Higgins (2002, Oikos, 99, 377-385) has closely studied the clutch size of Nephila maculata, a species well-known for the (very) large size of the females. 

"These spiders lay very large egg sacs (all  > 3000 eggs)" (page 380)

Still more precisley (page 382), Linden Higgins has shown that: "Female fecundity (number of eggs laid per clutch) is a function of prelaying mass".

N eggs = 1459.2 (mass) − 344.22, with R2 = 0.99.

The mass of the largest female sampled by L.H. was 6.9g (!) and so, it may be easily calculated that the clutch size of this female was equivalent to 9724 eggs. This value may be checked as a real one with the help of the Figure 5 (page 382, too).

I have attached the paper.

My two cents! All the best, Philippe.

Hello Dear

Spiders need to be fed only once every 3-7 days.

diagram of tank to rear spiders inMoisture is a more critical factor for the survival of spiders in captivity. One of the ways to keep the container moist without drowning the spider is to place a small potted plant inside the cage; another way is to place a ball of cotton wool or a folded filter/toilet paper which can be wetted with a few drops of water every day. Best regards

Karl, did you have any success in finding a collaborator?  How is the work going?  Are you focusing on any particular genus? 

now that I can enlarge photo, I'd also suggest to take a look at Nigma walckenaeri. Known european Sparassidae usually are not that green when being juveniles and it does not look like a Thomisidae anymore.

Hello Pir,

I can't think of a single paper dealing with spiders in Tobacco from North America.  On Google Scholar I saw a few papers dealing with spiders and other predators of tobacco cutworm, Spodoptera litura (Lepidoptera, Noctuidae) in Asia.  

Best regards,

Mike Draney.  

In addition to the methods described above, a D-vac (modified garden vacuum) can be a very efficient tool to collect spiders. This method enables you to catch spiders from almost all strata (from ground dwelling wolf spiders up to spiders walking on twigs). It is also one of the best methods to quantify spider densities by sampling a defined area.

See for example (http://onlinelibrary.wiley.com/doi/10.1111/j.1570-7458.2010.01094.x/full) for a critical discussion of suction sampling.

Although some companies offer D-vac's for arthropod sampling, it is relatively easy (and often cheaper) to modify a garden vacuum into a powerful tool for field ecologists.

Thanks!

Dear David,

that's nice thanks a million - love that!

All the best to London,

Sebastian