Meeting 1230 Minutes

The 1230th meeting of the Cambridge Entomological Club was called to order by President Jacob Dayton at 7:45pm on Tuesday, January 9, 2024. 15 members and guests attended with additional attendees on Zoom.

Old business:
The Club approved four new members: Daniel Toner, Myra Vidal, Ella Frigyik and Andrew Cameron.
Treasurer Jay Shetterly reminded members that dues are due.
Plans for the 150^th anniversary of the club are ongoing.

New business:
Six new nominees applied for membership: Michael La Scaleia, Billy Hickey, Elio Challita, Jorge Romero, and Yuttapong Thawornwattana.

The Harvard Museum of Natural History is planning an outreach program on insects in March. Talk to Jacob if you’d like to participate.

Our speaker was Willem Laursen, previously at Brandies University, now at the University of Washington. His talk was entitled “Up Close and Personal: Heat and humidity detectors for mosquito host-seeking and egg-laying behaviors.”

Female mosquitoes utilize host-associated cues to home in on the sources of the blood they use to nourish their developing eggs. From meters away, they detect elevations in CO2, odors, and visual cues. At close range, increased temperature and humidity associated with the ~3cm “boundary layer” of warm, moist air surrounding the host provide host proximity information and influence landing decisions. Humidity cues take on additional significance for post-blood feeding behaviors by signaling the presence of standing water for egg laying. The molecular mechanisms underlying mosquito heat and humidity seeking have remained elusive. Dr. Laursen discussed mosquito rearing methods, genetic manipulation techniques, and physiological and behavioral assays to identify and characterize the thermosensory and hygrosensory systems that support the blood-thirsty behaviors of vector mosquitoes.

Conclusions: Ionotropic receptor Ir21a drives heat sensing in mosquitoes, repurposing an ancestral thermoreceptor found in non-blood feeding diptera. Additionally, ionotropic receptor Ir93a-dependent sensors promote detection of heat and humidity. Both Anopheles gambiae and Aedes aegypti rely on Ir93a to blood feed and locate egg-laying sites. In mutant mosquitoes generated by genetic manipulation in Dr. Laursen’s lab, heat and humidity sensing were found to be impaired.

The meeting was adjourned at 8:57.