Cicadology (CICADAS) with Gene Kritsky

Episode Summary

Executive Summary: This episode is a lively deep dive into periodical cicadas with entomologist Dr. Gene Kritsky, covering Brood X/10 emergence timing, underground development, mating and song behavior, cultural meaning, food uses, declining populations, and the new Cicada Safari app that helps track sightings. The conversation mixes science, history, and humor while emphasizing that cicadas are remarkable, climate-sensitive insects worth protecting and observing.

Main Topics: Brood X/10 emergence and timing (Priority: 5/5): The episode centers on the 17-year periodical cicada emergence expected in 2021, including where it appears, when it starts, and how soil temperature and rainfall trigger mass surfacing. Life cycle and underground development (Priority: 5/5): Dr. Kritsky explains the full cicada life cycle: nymphs feeding underground for years, emerging, molting, hardening, mating, laying eggs, and restarting the cycle. Sound, mating, and predator satiation (Priority: 5/5): The episode details how males produce loud calls with timbals, how females respond, and how huge synchronized numbers overwhelm predators and improve survival. Scientific history and mapping of broods (Priority: 4/5): Gene discusses historical records dating back centuries, his archival mapping work, brood distribution, and how old newspaper and library records helped define cicada broods. Cultural significance and pop culture (Priority: 3/5): The show explores cicadas in Chinese, Japanese, Indigenous, and U.S. culture, plus references in music and literature such as Bob Dylan and historical accounts. Citizen science and the Cicada Safari app (Priority: 5/5): Listeners are encouraged to use a free app to submit geotagged photos and videos, helping scientists map brood extent and monitor emergence patterns in real time. Threats, climate change, and conservation (Priority: 4/5): The conversation raises concern about brood decline, habitat loss, climate-driven timing shifts, and the possibility that earlier or off-cycle emergences may alter brood patterns.

Key Arguments: Periodical cicadas emerge in synchronized massive broods, which likely evolved as a predator-satiation strategy that improves survival. Cicadas are climate-sensitive: soil temperature, rainfall, and seasonal leaf development all influence emergence timing and may be shifting with warming. The insects spend nearly their entire life underground feeding on xylem, not hibernating, and grow slowly through multiple instars. Male cicadas generate their loud chorus with abdominal timbals and resonance from a hollow abdomen; the sound can reach extreme decibel levels. Historical records show that mapping cicada broods requires archival research; older newspaper accounts and USDA documents are essential scientific evidence. Citizen science tools like Cicada Safari can produce tens of thousands of verified observations and help track brood health and range. Some brood populations appear to be declining or fragmenting, so public observation and protection matter for future generations.

Data Points: Brood emergence interval: 13 or 17 years - Periodical cicada life cycles discussed throughout the episode Brood discussed: Brood 10 / Brood X - The episode focuses on the 17-year Brood 10 emergence Soil temperature trigger: 64°F - Nymphs begin emerging when soil reaches this temperature First signs in soil: 4 to 6 inches below the surface - Where nymphs are located before emergence Tunnel chimney height: up to 12 inches - Mud turrets/chimneys can rise above ground in heavy clay soils Observed density: 356 per square yard - Highest density Gene reported during an emergence Emergence duration: about 2 weeks - Rolling period for adults to come out of the ground Wing/hardening window: about 90 minutes + 90 minutes - Time for wing inflation and exoskeleton hardening after molting Maximum recorded sound: 96 decibels - Measured chorus volume from some species in the field Other reported sound level: up to 120 decibels - Cited as a high end for some cicada choruses Egg count per female: about 506 eggs average - Student study counting eggs from sampled females Egg range: 400 to 600 eggs - Observed variation among females Number of eggs counted in research sample: 16,000 eggs - Total counted across sampled females Egg hatch time: 6 to 8 weeks - Time from egg-laying to hatch Underground feeding depth by New Year: 10 to 12 inches below surface - Nymph depth during winter development Historical record start: 1634 - William Bradford’s early colonial account of cicadas Historic archive count: 7,000 to 8,000 records - Gene’s archival mapping database size Cicada Safari expected submissions: 50,000 to 65,000 photos - Projected volume for the citizen-science app Brood decline example: Brood 11 went extinct in 1954 - Example used to illustrate brood vulnerability Climate shift example: May 28–29 to May 13–16 - Cincinnati average emergence timing has moved earlier since 1950

Pivotal Quotes: "The highest density I've ever seen was 356 per square yard." — Dr. Gene Kritsky: Describing the sheer scale of a Brood 10 emergence "The first steps towards wisdom is calling things by the correct names." — Dr. Gene Kritsky: Explaining why he insists on calling it Brood 10 rather than Brood X "They look kind of like ghosts that have been frozen to me." — Dr. Gene Kritsky: Describing the cicada exuviae left behind after molting

Implications: Listeners are urged to observe and document cicadas, not fear them; the episode frames them as a climate-sensitive natural spectacle and a conservation concern, with citizen science potentially shaping brood research and future protection.