Johnson, Robert L. and Van Dusen, Peter J. and Toner, Jason A. and Hairston, Nelson G. (2000) Eurasian watermilfoil biomass associated with insect herbivores in New York. Journal of Aquatic Plant Management, 38, pp. 82-88.
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A study of aquatic plant biomass within Cayuga Lake, New York spans twelve years from 1987-1998. The exotic Eurasian watermilfoil ( Myriophyllum spicatum L.) decreased in the northwest end of the lake from 55% of the total biomass in 1987 to 0.4% in 1998 and within the southwest end from 50% in 1987 to 11% in 1998. Concurrent with the watermilfoil decline was the resurgence of native species of submersed macrophytes. During this time we recorded for the first time in Cayuga Lake two herbivorous insect species: the aquatic moth Acentria ephemerella , first observed in 1991, and the aquatic weevil Euhrychiopsis lecontei , first found in 1996 . Densities of Acentria in southwest Cayuga Lake averaged 1.04 individuals per apical meristem of Eurasian watermilfoil for the three-year period 1996-1998. These same meristems had Euhrychiopsis densities on average of only 0.02 individuals per apical meristem over the same three-year period. A comparison of herbivore densities and lake sizes from five lakes in 1997 shows that Acentria densities correlate positively with lake surface area and mean depth, while Euhrychiopsis densities correlate negatively with lake surface area and mean depth. In these five lakes, Acentria densities correlate negatively with percent composition and dry mass of watermilfoil. However, Euhrychiopsis densities correlate positively with percent composition and dry mass of watermilfoil. Finally, Acentria densities correlate negatively with Euhrychiopsis densities suggesting interspecific competition.
|Title:||Eurasian watermilfoil biomass associated with insect herbivores in New York|
|Journal or Publication Title:||Journal of Aquatic Plant Management|
|Page Range:||pp. 82-88|
|Issuing Agency:||Aquatic Plant Management Society, Inc.|
|Additional Information:||July 2000 Special Issue: The Use of Native Insect Herbivores for the Management of Eurasian Watermilfoil|
|Uncontrolled Keywords:||Myriophyllum spicatum,Acentria ephemerella,Euhrychiopsis lecontei, biological control, herbivory, Cayuga Lake, Eurasian watermilfoil, New York, aquatic moths, aquatic weevils|
|Depositing User:||Stephanie Haas|
|Date Deposited:||16 Feb 2009 03:14|
|Last Modified:||29 Sep 2011 21:58|
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