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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Invasive Species and Pollinator Health » Research » Publications at this Location » Publication #383162
Research Project: Integrated Weed Management and Restoration Strategies to Protect Water Resources and Aquatic and Wetland Ecosystems of the Far Western U.S.

Location: Invasive Species and Pollinator Health

Title: Biological control of water hyacinth, Pontederia crassipes (C. Mart.) Solms (Pontederiaceae), in California: Release and re-distribution of biological control agents 1987–2006

Author
item PITCAIRN, MICHAEL - California Department Of Food And Agriculture
item Pratt, Paul
item VILLEGAS, BALDO - California Department Of Food And Agriculture
item POPESCU, VIOLA - California Department Of Food And Agriculture
item BORKENT, CHRIS - California Department Of Food And Agriculture
item Reddy, Angelica

Submitted to: The Pan-Pacific Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/27/2021
Publication Date: 7/30/2021
Citation: Pitcairn, M.J., Pratt, P.D., Villegas, B., Popescu, V., Borkent, C., Reddy, A.M. 2021. Biological control of water hyacinth, Pontederia crassipes (C. Mart.) Solms (Pontederiaceae), in California: Release and re-distribution of biological control agents 1987–2006. Pan-Pacific Entomologist. 97(2):55-66. https://doi.org/10.3956/2021-97.2.55.
DOI: https://doi.org/10.3956/2021-97.2.55

Interpretive Summary: Waterhyacinth is a serious aquatic weed in lakes, ponds, and waterways in California and around the world. Two weevils (Neochetina eichhorniae and Neochetina bruchi) and a moth (Niphograpta albiguttalis) were released at four sites in 1982–1987 for the biological control of waterhyacinth in the Sacramento-San Joaquin River Delta. Here we report on statewide efforts to distribute these insects outside the Delta and subsequent surveys to determine their establishment. From 1987–2006, the three insects were redistributed to seven locations in five counties (Fresno, Los Angeles, Merced, Sacramento, and Santa Cruz) in California. Surveys in 2018-2020 found both weevils at two locations in Merced County and one location in Sacramento County. No weevils were found at release locations in the upper San Joaquin River and associated waterways in western Fresno County or at the release location in Santa Cruz County. Plants at the release locations in Los Angeles County and eastern Fresno County were later eradicated and not sampled in this survey. These recoveries expand the known location of the weevils in central California. The moth was not recovered during any of the surveys.

Technical Abstract: Waterhyacinth, Pontederia (=Eichhorniae) crassipes (C. Mart.) Solms (Pontederiaceae) is a serious aquatic weed in lakes, ponds, and waterways in California and around the world. Three insects, Neochetina eichhorniae Warner, 1970, Neochetina bruchi Hustache, 1926 (Coleoptera: Brachyceridae), and Niphograpta (=Sameodes) albiguttalis (Warren, 1889) (Lepidoptera: Crambidae)) were released at four sites in 1982–1987 for the biological control of waterhyacinth in the Sacramento-San Joaquin River Delta. Here we report on statewide efforts to distribute the biological control agents outside the Delta and subsequent surveys to determine insect establishment. From 1987–2006, the three insects were redistributed to seven locations in five counties (Fresno, Los Angeles, Merced, Sacramento, and Santa Cruz) in California. Surveys in 2018-2020 found both Neochetina weevils at two locations in Merced County and one location in Sacramento County. No weevils were found at release locations in the upper San Joaquin River and associated waterways in western Fresno County or at the release location in Santa Cruz County. Plants at the release locations in Los Angeles County and eastern Fresno County were later eradicated and not sampled in this survey. These recoveries expand the known location of Neochetina weevils in central California. The hyacinth moth, Ni. albiguttalis, was not recovered.