Meeting 1228 Minutes
The 1228th meeting of the Cambridge Entomological Club was called to order by President Jacob Dayton at 7:43pm on Tuesday, November 14, 2023. Approx. 25 members and guests attended.
New business:Treasurer Jay Shetterly reminded members that dues are due: $5 for students, $25 for others, and $50 for a lifetime membership. He also has Chinese journals available to members who might want them.
Plans for the 150th anniversary of the club are ongoing. Scott Smyers is looking for members to help organize events in the White Mountains this summer. Plans for a local observance are also underway.
VP Sarah Dendy and former President Katherine Angier attended the 2023 meeting of the Entomological Society of America. A new committee on insect decline aims to find ways that ESA can help fight insect decline and raise awareness of it. Sarah and Kat have signed up for future committee communications and invite interested club members to contact Sarah if they wish to be added to the email list.
Our speaker was Helen McCreery, Lecturer in Biology at Tufts University, who discussed her work in a talk entitled “Problem solving and flexible control in self-organized collectives”
From subcellular processes to animal migrations—groups can accomplish tasks well beyond what individuals can. There are many benefits to collective action— e.g. it is typically scalable and robust—but also costs, including high “inertia”, which can result in a loss of flexibility.
Dr. McCreery discussed the mechanisms of ants’ collective action in two tasks that require extreme cooperation: self-assembly of living bridges in Eciton army ants, and maze-like obstacle navigation during cooperative transport by Paratrechina longicornis (crazy ants).
Starting with dynamic control of self-assembled bridges in Eciton army ants, Dr. McCreery described how bridge-building ants contend with unstable foundations, such as twigs and leaves, that create varying gap sizes and require varying numbers of ants to join or leave depending on conditions. Dr. McCreery made field observations using a setup that allowed her to create expanding and contracting “gap” sizes. Based on data collected from these observations, she created “linear” behavioral models (which failed) and more successful, accumulator models where decisions to join an expanding bridge or leave a contracting bridge took hysteresis (difference between current and equilibrium states) into consideration.
In her collective transport work with crazy ants, she created simple and more complex barriers for the ants to encounter while attempting to transport bits of tuna back to their nest. To accomplish their goal, the ants needed to agree on a travel direction which in the case of the complex barrier, sometimes required them to travel away from their ultimate destination. Their goal was eventually reached through trial and error, with the ants gradually expanding their traveled area until they cleared the obstacle.
After the talk, Jay Shetterly brought part of his collection of Tiger beetles and Avalon Owens brought a live “warty glowspot” roach to share with the group.
The meeting was adjourned at approximately 9:15
