> clearly is washougalia, which is the same species as D. lana

Interesting, both are Levi, 1953. So which one becomes the senior species? The first one mentioned? An alphabetical decision?

Since they were both named at the same time I have no idea which name would be picked. Maybe they would leave that to Levi or to the person that publishes the paper that describes how they are the same species?

For our purposes I think we're fine using D. washougalia and putting Rod's comments on the info page.

Hi Lynette,

(Welcome back) Yeah I wasn't thinking of BG, and the synonymy has never been published. I wonder if Rod files the females under lana and the males under washougalia... ;-)

Asking the author won't work as he or she may be long gone when the matter arises. My guess is that this is based on first mention in the article.

Found the answer: "Senior synonyms: The oldest of two or more names that are considered valid by nomenclatorial codes. This is usually based on priority, but may also be done on the basis of choice of names by the first revisor (zoology) or by a nomenclatorial governing body."

So, unless the future reviser decides otherwise, the senior name would be washougalia ( a name that is in any event too good to give up).

I see what you mean. I'm not sure how Rod files his... I'd guess he's picked one name or the other since it seems silly to continue to call them both names when he knows they are the same species. I wonder if we can get Levi's take on this?

"Concerning lana vs. washougalia, it's up to the first person who publishes the synonymy in print. If it were me I'd pick lana (which is what I file my specimens under), since I much prefer shorter names."

I look forward to seeing a published revision by Bennet and Crawford, partly to find out how they determined the male and female belong to the same species.

I'd guess it's from collecting them together in the field.

Aha, clearly an extraterritorial pact to keep this an open secret... :-p

Thanks for bringing us in on it.

nice one!

The profile of the carapace is actually what lead me to Dipoena. I was thinking D. malkini until I compared the palps because I thought the pattern looked similar to the drawing of the female (fig. 8), and the carapace depression was shaped like in fig. 63.

Regarding the pattern, maybe it's regionally variable? Levi doesn't list records for D. washougalia like for many other species, so maybe the collection at the AMNH only had spiders from Washougal. At least at the time the paper was written.

I'm keeping my eyes peeled for more individuals like this and the earlier female. The immature males disappeared the next day. It'd be interesting to arrange a "date" and see what happens.

Rod Crawford would be the one to ask.

These specimens might be worth collecting.

This probably seems obvious, but if you have both adult spiders at the same time see if they will mate.

Another way is to raise several spiderlings from the same egg sac and hope that some of them turn out to be males and some females.

Another way, find a male and female together in the same web and they're probably the same species (but getting them to mate would help to make sure).

I don't know how else you would establish that a newly-discovered-but-undescribed female is the same species as a known, described male unless you link them in one of these ways.

The reason I wondered whether catching them in the act of mating was sufficient was that I've heard about hybridization with some species (eg. Bassaniana utahensis/versicolor). Raising spiderlings from the same egg sac sounds like a sure-fire way to find out, though!

Yes, you'd have to beware of hybrids, but how often does breeding between two different species occur among entelegynes, I wonder?

Good point. Very rarely, I guess, and then only between species with similar enough genitalia. Thanks!

And even then nature throws up other barriers that tend to prevent interbreeding: different mating behaviors; different species living in different habitats or microhabitats so that they rarely encounter each other (one lives on the ground, the other in trees, for example); adults of different species maturing and breeding at different times of the year, etc.

And, even if similar species do interbreed there are other barriers to producing young: the egg of one species does not "recognize" the chemistry of the sperm of another so that the sperm cannot penetrate the egg, so no fertilization occurs; the hybrid embryo contains conflicting genetic instructions on how to develop, and so the embryo dies; the two species have a different number of chromosomes (which is the case with horses and donkeys, I believe), so that even if they mate and produce offspring, those offspring are sterile; etc.

Interbreeding in the wild still happens, though. Some closely related species, such as the red-shafted and yellow-shafted woodpeckers, form a "hybrid zone" where their distributions overlap. In this zone the two species encounter each other, interbreed and produce hybrids. This sort of interbreeding makes it difficult to decide whether the two types of wood peckers, though apparently different on their own respective sides of the zone, are actually separate species (Solomon, Berg, & Martin. (2008) Biology. 8th ED. Brooks/Cole, Cengage Learning. pp. 437-438).

I wonder if such a zone has been documented anywhere among spiders?

Successful interbreeding is definitely possible among entelegynes, though. Foelix (1996) mentions an interesting experiment involving the closely related species Schizocosa ocreata and Zchizocosa rovneri. They do not normally interbreed because of different mating behaviors that prevent the female of one species from accepting the advances of the male from the other species, even though their genitalia are very similar. In the experiment, the female of one species was anesthetized and so a male of the other species was then able to mate with her. The female later produced eggs that hatched into hybrids (The Biology of Spiders, 2nd Ed. 1996, p.182).

Foelix writes that behavior is a more effective barrier to interbreeding between closely-related species of spiders than differences in genitalia .

Really interesting! Particularly the importance of behavior illustrated in the Schizocosa example. I've got to read The Biology of Spiders, I've heard it mentioned several times now and it sounds very worthwhile.

Regarding hybrid zones for spiders, I checked out the resource from the Bassaniana info page. On page 10 of the PDF it's suggested there might be such a zone for B. utahensis and B. versicolor.

Yes you'll enjoy Biology of Spiders, an indispensible volume.

Thanks for the posting, John, very interesting.

Bassaniana was also my first thought with respect to hybrid zones. I just looked at another specimen from Tom Murray that, I could imagine, might be a hybrid (again, depending on how much variation in embolus shape, etc. is permissible within the true species).