True Stories Of FidoNet

What Insect eats Cyanide?

Hydrogen cyanide is one of the most toxic substances, so it is no surprise that some plants use it in defense. The cells of tropical passion vines have two kinds of tiny compartments. One kind of compartment contains an enzyme (a protein catalyst), and the other contains a chemical called a cyanogen. When a bug eats a leaf and crushes its cells, the enzyme and the cyanogen mix, forming deadly hydrogen cyanide gas.

Yet the caterpillars of the blue Grecian butterfly (Heliconius sara) eat nothing but those same leaves. How do they avoid being poisoned?

The secret is in the caterpillar's saliva. It contains special enzymes that quickly attack the cyanogen, changing it so that the cyanide gas is not produced. But the evolutionary arms race is not over, since some passion vines grow sharp hooks that rip open unwary caterpillars.

A recent study revealed the caterpillars' secret:
http://www.bric.postech.ac.kr/science/97now/00_7now/000713a.html

H. sara can be found in Central and South America:
http://www.butterflies.org.uk/lbh_home/tropical/costaric/h_sara.htm
http://www.rlephoto.com/troplep/Heliconius_sara003s.htm

Animals can also use cyanide for defense:
http://features.LearningKingdom.com/fact/archive/1998/05/22.html

JPL Lab Report on Climate

The El Nino and La Nina events of the past few years may have faded into climate history, but the Pacific Ocean has not calmed down. The latest satellite data from the U.S.-French TOPEX/Poseidon mission show that the entire Pacific basin continues to be dominated by the strong and stable Pacific Decadal Oscillation's (PDO) characteristic warm horseshoe and cool wedge pattern. The PDO is a long-term ocean temperature fluctuation of the Pacific Ocean that waxes and wanes approximately every 10 to 20 years.