Response to vibrations in web

This page covers an experiment done in the lab, testing the reactions of Latrodectus to different frequencies of vibrations (theoretically similar to prey items) in the web. Both groups consisted of female spiders. Group 1 had a juvenile (near 4th instar) and a mature female. Group 2 consisted of the same. Group 1 was fasted for about month before the testing occurred, whereas group 2 was fed multiple times leading up to the testing. I thought that group 2 would not react as quickly as group 1, but that was not the case. Tuning forks of different frequencies were smacked, then immediately placed onto the web. Reaction time and response was noted.

I would have liked sample size to be a bit larger, and more in-depth testing was desired as well, but due to the nature of the assignment and time period allowed, this had to do :)

The best results for us came with the lowest frequency. 100Hz is approximately equal to the frequency of the G2 key (#23) on the piano.

HERE is an image of a piano with numbered keys for reference.

Unfortunately, we did not have any larger / lower frequency tuning forks to see if the reactions of the spiders got quicker or more intense. Perhaps they would have ignored lower frequencies much like they ignored very high frequencies. Further testing to come I guess :)

The image below shows the response of "Immediate Reaction (with silk)." To me, this best demonstrates the reaction similar to when prey is in the web. The spider would rush the fork, and start to swathe it with sticky threads.