November, 1999

Extinction Not a Sure Thing
Since 1929 the San Fernando Valley spineflower was considered an extinct species. Recent environmental site surveys for the proposed Ahmanson Ranch subdivision in Ventura County turned up the spineflower plus two other endangered species—the red-legged frog and Braunton’s milk vetch. Another “extinct” plant—the Ventura marsh milk vetch—was discovered earlier at another development site near Oxnard (LEAF-let Jul/Aug ’98). These discoveries prompt us to wonder if subsequent Ventura County building sites will produce other extinct species, perhaps the passenger pigeon and the do-do bird.

Just Can’t Win
In still another example of nature’s perversity, a recent study by the National Center for Atmospheric Research suggests that the country’s success in cleaning the air could contribute to global warming. According to the EPA, sulfur dioxide emissions—responsible for acid rain and health problems—have dropped by 12 percent between 1988 and 1997. As the atmosphere becomes cleaner its ability to filter out sunlight diminishes, creating increased warming. A number of computer forecasts suggest cleaner air will add one degree to global warming estimates over the next 100 years.

Beneficial Bacteria Cleans Lakes
Nonchemical “good bacteria” controls are gaining popularity in protecting lakes and ponds from “bad bacteria” infection. Long the exclusive purview of chemical agents, sick waters are responding to natural fixes. Just as natural bacteria are responsible for breaking down sewage and other waste products, so to do the “superbug” concoctions from Enviro-Reps International, a Camarillo company.

A Real Dust-up
The Journal of Geophysical Research reports on a University of Miami Rosenstiel School of Marine and Atmospheric Science study showing nearly half the dust in Miami on summer days originates in Africa. Transoceanic winds bring the dust, which is high in iron content. The dust nears the EPA’s allowable limits for airborne particulates.

Weird Sex
The Kesterton National Wildlife Refuge near Merced has shown a dramatic increase in certain mice and voles possessing both male and female reproductive organs. The cause of this hermaphroditic condition—found in a third of individuals in a recent sampling of 87 animals is unexplained. Scientists suspect that the cause is of environmental, rather than genetic, origin. The area was the site where once thousands of birds were killed by selenium from agricultural runoff.

The Perp is a Lerp
Redgum lerp psyllids attack eucalyptus trees and are resistant to both pesticides and native insect predation. Originating in Australia, the psyllid resembles an aphid and builds a fibrous shell (a “lerp”) on eucalyptus leaves. Psyllids suck juices from the leaves, killing them. There are no known natural enemies of the organism in the U. S. Scientists, however, have returned from Australia with a shipment of tiny non-native parasitic wasps that prey on psyllids and which may be the saviors of our non-native eucalyptus trees.