CURM Tenth Meeting, 11/06/2008

Dr. Jim Cushing joined us for a meeting with Jon Hastings. Dr. Cushing is a professor of mathematics at the University of Arizona, and specializes in mathematical biology -- he's famous as a member of "The Beetle Team". A couple of notes follow:

• Dr. Hastings explained that the nymphs of cicadas are xylem feeders. Xylem is a very poor medium for growth, and may explain why it takes the cicadas so long to develop.
• Dr. Cushing wondered if it was nymph competition that might have caused the cicadas to begin the synchronization (e.g. 13 year, 17 year cicadas).
• Dr. Hastings imagines that underground there are lots of these nymphs attached to lots of roots, awaiting their moment.
• $R_{0}$ -- expected offspring over all life cycles
• semelparous dynamics $\implies$ eigenvalues are (proportional to?) roots of unity, so they cross the unit circle simultaneously -- which can lead to the synchronized emergence.
• Maxine Heath is a cicada systematist, retired from Southern Ill. University at Carbondale.
• Simon is another who might be able to give us some counts on cicadas -- he's out east.
• Protandry: the condition in which an organism begins life as a male and then changes into a female

The question Jim ended up asking, and the one that I'm ashamed that we hadn't asked, was this: has anyone ever seen a wasp pass up a cicada? If not, they're probably indiscriminate hunters.

So we wondered if we might actually be able to do the experiment: place a large number of variably sized cicadas in an area with lots of cicada killing wasps, and see what the wasps do....