Photo Adventures with Curiosity and Learning


June 24, 2007: Male and Female Nephila: the mating game starts

What a surprise. I went out about 3pm - just as the rain started. Bummer. When I got to my spot, I started my Nephila hunt and the first web - WOW - a male starting the mating game. Matjaz Kunter (from the University of Slovenia) and Li Daiqin (from NUS) provided some hints about mating behavior. The male wraps the female head with silk. I had seen this earlier but not recognized it. This time, I used my 180mm lens and got a closer look at the male and female. No wrapping yet, but what I found was a surprise. There is a white line along the long axis of the dorsal side of the female abdomen. In one of my photos, I could see that the male was anchoring himself to the females dorsal side. My speculation is that this white line represent the dragline anchor points of the male. You be the judge.

Here is an overview and size scale of the male-female positioning and the web. The fale is located over her left rear leg (orangish spider) and is about 1/50th the size of the female.

Male and female
Nephila

from the side

Male and female Nephila
from the side

A closer view. About the silk strand along the midline of the female abdomen. This looks to be too large to have been placed by the male. Is this from the female (you can see in the upper left that it appears to wrap around her abdomen and directed toward her spinneret) and a signal to male(s) that its time to start mating? Does it provide anchor points for the males?

jun 24 0131 male dragline path

And and even closer view

jun 24 0162 male dragling path

Here is a view of the female Nephila with the male. Note the black palps and the hint of a dragline from his spinneret that is connected to the white more-or-less vertial trace of spider silk.

jun 24 0043 male nephila

Though not well focused, you can see what appears to be silk connecting the male with the dorsal side of the female. (It could also be an out of focus leg segment).

jun 24 0078 male dragline

There was very interesting behavior. Every few minutes, the female would sort of do a dance with her legs as if trying to clear something from the air. Here her legs are raised.

jun 24 0090 male female

Look at the white vertical silk strand. It is separated from the surface of her dorsal abdomen - as if stretched tighly from the rear of her abdomen to the hum uner the male abdomen - and under the rear male leg, suggesting that this is an anchor line used by the male

jun 24 0091 male side

Here he moves backward - and what I thought was silk from his spinneret is a segment of one of her rear legs.

jun 24 0111 male dragline

and then moves forward over her cephalo-thorax

jun 24 0118 male on head

A closer view. Lookling closely at the silk strand on her dorsal surface, is it possible that she actually placed this as a signal that the mating game should start. Looking to the left, it appears to wrap around her abdomen, perhaps terminating at her spinneret. After a while he left her and retreated to the top of the web.

jun 24 0165 male dragline dorsal

as shown here. Note again the size scale and the black palps of the male.

male Nephila escapes

Here he is doing some sort of acrobatics - note the black color of his palps.

male Nephila

Here he appears manipulating a strand of silk

jun 24 0204 male argyrodes acrobat

More acrobatics

orange spider

And here she is without her male suitor

no male Nephila

Marching along the edge of the forest, I found another web with Argyrodes so it is probably an older web. This little guy was hanging around the top and I think that perhaps it is a male Nephila?

Nephila and argyrodes

One of the 5 or 6 Argyrodes

Argyrodes

Another view of the male Argyrodes

Argyrodes

Another one

Argyrodes

and true to their reputation - here is a hole created by the Argyrodes - clearly an indication that tasty treats were not available

Argyrodes hole

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This work is licensed under a Creative Commons License.

C. Frank Starmer

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