Orbweavers from Hawaii

Argipoe appensas mating activity
Fri, Feb 27, 2009 at 12:01 AM
I got this shot of a male Argipoe appensas? after it spent some time on the web of a female. I did not get a shot of the actual mating. I’m not sure it occurred. However, I wonder if the small appendage and organ to the left of his head are sex organs and/or sperm packets?
gregp25
Kapaa, Kauai, Hawaii

Pair of Orbweavers
Orbweavers

Dear gregp25,
Thanks for sending us a photo of a pair of Argiope appensa preparing to mate. The much smaller male will spend considerable time in the web of the female until he has an opportunity to mate. In speaking about a related species, Argiope aurantia, BugGuide mentions the palps on the male spider being reproductive organs. The Biodiversity Explorer website discusses the copulatory organs of spiders thus: “The copulatory organs of the Araneomorpha, or true spiders, have entelegyne features. The male palps are enlarged distally (at the ends) due to a complex copulatory organs or genital bulbs that resemble boxing gloves. Some tiny male spiders have ridiculously large palps relative to their body size. The male and female genital organs are very specific and function on a “lock and key” principle. These organs are used to identify spiders to species level. The female genitalia, the epigyne, is situated ventrally (underside) between the booklung slits on the epigastric furrow. The epigyne is a black, shiny, chitinous, oval to round plate with two openings. “

Male Orbweaver
Orbweaver

Correction: Mon, Mar 2, 2009 at 8:13 AM
Aloha Daniel –
Regarding the post on Sunday:
A pair of Orbweavers from Hawaii
Argipoe appensas mating activity
Fri, Feb 27, 2009 at 12:01 AM
The photo from Kaua`i appears to have an adult female and a sub-adult female. Also, the writer is confusing the stabilimentum with something to do with reproduction.
The observations I’ve made of the males on Maui are that they have very little of the same markings on their back as the female. They are also seriously small compared to the females. Most people totally miss the boys hanging out on the other side of the web because of their X shape and the general size of these girls.
Also, regarding the first image – the male would need to be on the other side of the web. It is the best place for them to sip on the meal provided by the female. But who knows what they do when I’m not looking at them? Ha!
The link you have to BugGuide – for the Argiope Aurantia – the male is really large compared to what I have seen here on Maui for the Appensas. Of course, with the way animals can adapt to their environments, Kaua`i appensas and Maui ones could be different!
Right now, due to the wet and seriously windy weather in Ha`iku, our Appensas are hiding in their appropriate safe zones so I can’t send you an image of a pair here. I will make sure you get an image when I can. Also will include an image of egg sacks, which look rather like a wrapped-up used food source.
These images are from lower Kula on Maui – 30 July 2005. I had a house with an outdoor shower and these girls shared bug reducing duties for me.
Mahalo – Thanks – for all the enjoyment your efforts bring to the world.
Eliza B

Argiope appensa
Argiope appensa

Thanks for correcting our error Eliza.

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