today
8:30 a.m. Audubon Society Field Trip See Event Description
read >9 a.m. Arcata Farmers' Market Arcata Plaza
read >9:30 a.m. Discovery Walk: Unknown Waterfront See Event Description
read >9:30 a.m. Manila Dunes Restoration Manila Community Center
read >10 a.m. Manila Dunes Guided Walk Manila Community Center
read >10 a.m. Library Book Sale Humboldt County Library
read >10 a.m. Dia de los Muertos and Mexican Folk Art Sale Private Eureka home
read >10 a.m. Final Arcata Farmer's Market Arcata Farmers' Market (off the plaza)
read >11 a.m. Donlin Foreman Dance Workshop Dell'Arte
read >2 p.m. Humboldt Coastal Nature Center Draft Trails Plan Walk Stamps House
read >5 p.m. Bati Zado and Show Redwood Raks World Dance Studio
read >6 p.m. The Tumbleweeds Chapala Cafe
read >6 p.m. Ali Chaudhary (jazz duo) Libation
read >6:30 p.m. Not Evil, Just Wrong Humboldt Area Foundation
read >7 p.m. Guitar Stan (country) Old Town Coffee & Chocolates
read >8 p.m. Guitar Orchestra of Barcelona Arkley Center for the Performing Arts
read >8 p.m. Stones in His Pockets Arcata Playhouse
read >8 p.m. A Christmas Carol North Coast Repertory Theater
read >8 p.m. Donna Landry Swing Dance Moose Lodge
read >8 p.m. North Coast Wind Ensemble Fulkerson Recital Hall at HSU
read >8:30 p.m. The Last Minute Men (international) Cafe Mokka
read >9 p.m. Ian McFeron Band (folk rock) Six Rivers Brewery
read >9 p.m. The Michael Paul Band WAVE @ blue lake casino
read >9 p.m. The Generatorz (classic rock) Central Station Cocktail Lounge
read >9 p.m. Taxi Bear River Casino
read >9 p.m. VJ Itchie Fingaz Pearl Lounge
read >9 p.m. Jack Ruby Presents + Blue Street + Acufunkture (DIY rock) Jambalaya
read >9 p.m. 2nd Annual Scorpio Bash The Red Fox Tavern
read >10 p.m. Music by DJ Sidelines
read >10 p.m. DJ Icy Hot Aunty Mo's Lounge
read >10 p.m. Jemimah Puddleduck (rock) Humboldt Brews
read >10 p.m. White Manna + Midday Veil + The King Salmon Duo (rock) Jambalaya
read >11 p.m. Radio Moscow (psychadelic blues) + Mosquito Bandito (one-man surf/garage) The Alibi Lounge and Restaurant
read >previous columns
July 3, 2008
Lagoons and Beaches
Lagoons Shelter Cove Much of our coastal topography is generated ...
read >June 26, 2008
Alien Plants
Pampas grass (Cortaderia selloana).Photo by Don Garlick. Which are the ...
read >June 19, 2008
Our Mattole Canyon
Just west of Cape Mendocino there exists a submarine escarpment ...
read >Photos
Pupal Memories
By Don Garlick
I remember watching a chick emerge from an egg. It was miraculous. I have also seen a mosquito dragging itself from its pupa, standing on water for a moment to inflate its wings, and then flying away in search of blood. It was equally awesome. I mention the mosquito to quell the enthusiasm of those who think that miracles created all life.
I herein explore insect metamorphosis in more detail, inspired by experiments regarding learning and memory. Insects mature though stages, called instars, separated by molts. Some insects undergo a spectacular transformation from larva to adult imago, while encased in a pupa. Such holometabolic insects include beetles, bees, butterflies, moths, flies, fleas and mosquitoes. Examples of insects that mature more gradually are grasshoppers, dragonflies, cicadas and aphids.
To quote the New World Encyclopedia: “In the pupal stage, the insect excretes digestive juices to destroy much of the larva’s body, leaving a few cells intact, while groups of cells, called imaginal disks, develop into tissues of the adult, using the nutrients from the broken down larva.” I was astonished, therefore, to learn of the following experiments by Douglas Blackiston, Elena Casey and Martha Weiss (Dev. Bio. July 2006 and Plos.org March 2008):
“During metamorphosis, insects undergo a drastic re-organization of the body; including widespread cell death and the proliferation of new tissue. The present study examined the ability of memory to survive metamorphosis, from the larval to adult stage, in Tobacco Hornworm Manduca sexta. Fourth instar larvae were electro-shocked in the presence of ethyl acetate to generate an odor avoidance behavior. Larvae were assayed for learning in a Y-choice chamber, and were additionally assayed as adults to assess if memory persisted through metamorphosis. Larvae demonstrated strong aversive learning, which was retained in subsequent adults. These are the first studies in Lepidoptera demonstrating memory through metamorphosis.”
So, we gain an appreciation for the learning ability of caterpillars and are astonished by the persistence of memory through a drastic redesign and restructuring of their bodies and lifestyles. The brain must surely retain some integrity during the process. Go find a Tomato Hornworm in your garden, teach it a trick like bright-light avoidance, guard it through the three weeks of metamorphosis, watch in amazement as it bursts from its pupa, and then test whether your moth resists its inherent tendency to spiral into bright lights.



















1. svemir:
July 11, 7:23 a.m.
This is indeed thought-provoking. I am glad our work at New World Encyclopedia was of some help. The quote above is from the Metamorphosis article.
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