From aceska@cue.bc.ca Wed Feb 10 14:29:58 1993 Date: 10 Feb 93 7:01 -0800 From: Adolf Ceska To: ben@cue.bc.ca Subject: BEN # 49 BBBBB EEEEEE NN N ISSN 1188-603X BB B EE NNN N BBBBB EEEEE NN N N BOTANICAL BB B EE NN NN ELECTRONIC BBBBB EEEEEE NN N NEWS No. 49 February 10, 1993 Address: aceska@cue.bc.ca Victoria, B.C. ---------------------------------------------------- COMING EVENTS IN VICTORIA Feb 12, 1993, "Grasslands and Oak Woodlands of the Pacific Northwest" slide presentation by Reid Schuller. Newcombe Theatre, 7:30 p.m., tickets $3/$2. Reid Schuller is a plant ecologist studying native plant communities and is currently involved as a natural area scientist, in Washington state, monitoring the restoration of grasslands and oak woodlands. Feb 18, 1993, "Costa Rica and Resplendent Quetzal" - world premiere of a video by Adolf and Oluna Ceska. Newcombe Theatre, noon hour (12:15 to 1:15 p.m.), admission free. Feb 19, 1993, "GARRY OAK MEADOW COLLOQUIUM" - University of Victoria, Elliot Building # 167, 8:30 a.m. - 5:00 p.m. Speakers will address Garry Oak vegetation, its origins, history, rare species, insects, vegetation management, community planning, and discuss the role of municipal governments and parks. Organized by Biology Department, UVIC with the help from the Garry Oak Meadow Preservation Society. For more information call Richard Ring (604-721-7102), Richard Hebda (387-5493), or Joyce Lee (386-3785). AQUATIC CATERPILLAR MAY CONTROL WATER WEED From: Chuck Goelzer Lyons [from ENTOMOL-L] A tiny caterpillar may be responsible for doing what herbicides and harvesters could not--controlling one of the worst aquatic weeds in the United States, Cornell University biologists say. The leaf-eating larvae of an aquatic moth may be the cause of dramatic declines observed in the weed, called Eurasian watermilfoil (Myriophyllum spicatum), in Ithaca's Cayuga Lake. If so, the moth could be a biological control agent, replacing or supplementing millions of dollars spent annually in the U.S. for artificial control. But more tests are needed to make that determination. "In the early 1970s, Eurasian watermilfoil made up 90 to 99 percent of the plant biomass in Cayuga Lake," said Robert L. Johnson, a Cornell ecology researcher. "The plants were growing from 3 to 20 feet long--and as long as 35 feet--starting from the lake bottom and reaching for light, forming dense canopies at the surface." Beginning in 1986, Johnson's annual surveys of Cayuga Lake aquatic plants found a steady decline in Eurasian watermilfoil. By 1992, the nuisance plant had diminished to 10 percent of its biomass in the 1970s. Searching for causes, he looked for the moth, Acentria niveus, which Middlebury College biologists previously reported in milfoil plants of Lake George, between Vermont and New York State. The insect, also an exotic (non-native) species, was identified near Montreal as early as 1927 and has since been collected in Massachusetts and on the Canadian and U.S. sides of the Great Lakes. The Cornell biologist found hundreds of insect larvae--each about the size, shape and color of a grain of rice--eating the tips of Cayuga Lake's milfoil in the summer of 1992. The tiny caterpillars use their silken thread to bind milfoil's feathery leaves into individual nests called larval retreats, effectively halting growth of the plant stems. When the caterpillars are not consuming leaves that hold their retreats, they dine out on other plant parts, Johnson said. The larvae are believed to spend up to 10 months of their lives under water, before emerging as adults. Male moths fly for a few days, then mate at the water's surface with females. Female aquatic moths submerge to lay eggs on underwater plants, and the cycle begins again. Cornell entomologists John G. Franclemont and E. Richard Hoebeke identified the Cayuga Lake moths as the same species or a close relative to the ones found in Lake George. Just because aquatic moths thrive where Eurasian watermilfoil declines does not mean a successful biological control for the weed has been found, cautioned Nelson G. Hairston Jr., a Cornell professor of ecology and systematics. Controlled experiments could determine whether other factors are involved, he said. For example, some disease may be affecting the plants' health, making them more vulnerable to insect predation. Or water turbidity (cloudiness) from algal blooms in the early season (when milfoil plants try to reach for the surface) may retard their growth, he said. At Cornell's experimental ponds, where controlled studies of aquatic weeds and other plants and animals are planned for 1993, biologist Johnson is not ready to ship moths to every lake with a Eurasian watermilfoil problem. But their presence, he said, complicates strategic planning for aquatic weed control. Weed-harvesting machines, which cut the tops of aquatic plants in some lakes, also may remove beneficial insects. The harvesting machines' effectiveness already is in doubt from Cornell studies that found weed-cutting may actually encourage weed growth, Johnson said. Stray pieces of aquatic weeds from the harvesters take root on lake bottoms, the same way gardeners produce new plants from cuttings. Further, the weed cutting only temporarily opens lanes for boating and swimming, Johnson's measurement of plant growth has shown. Like a fresh-mown (and well-watered) lawn, the Eurasian watermilfoil soon rebounds even stronger than before. TAXONOMISTS CHARGING THEMSELVES INTO OBLIVION [Re: BEN 48] From: C.J.O'Kelly [from USENET] Dammit be careful out there!!! Some years ago, the Botany Division of New Zealand's Division of Scientific and Industrial Research (DSIR) came to a similar conclusion, that the day of free taxonomic IDs was at an end. Hence they began charging. >From that day these guys were dead. Identifications made for clients dropped from several per day to a few per month. Didn't matter what the fee was, the clients didn't come back. Didn't take the administrators more than a few clicks on their calculators to discover that the users were not paying for the service and were not going to. Within two years, Botany Division was dead, with most of its staff in taxonomy gone or going (I think the herbarium curator is all that remains). The New Zealand University teaches taxonomy. Just as well given the caliber of the students who fool themselves into thinking they're learning it. Get real. Underpayment is better than no payment. And it may mean that there are a few individuals left to pass on their expertise when, in thirty years, folk finally recognize what they've done by killing off the field that answers the first question of biology ("What is it?"). DON'T OVERLOOK ! Gayton, D. "Big bluestem and a tallgrass dream." Equinox No. 67 (January/February 1993): 30-39. Don Gayton describes the work of John Morgan and his effort to reconstruct the tallgrass prairie near Winnipeg, Manitoba. In the same Equinox issue is a nice article on hummingbirds.