Location: Invasive Plant Research LaboratoryTitle: Specificity of Lepidelphax pistiae (Hemiptera: Delphacidae) to Pistia stratiotes (Araceae) Author
Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2013
Publication Date: 3/1/2014
Citation: Walsh, G.C., Maestro, M., Sosa, A., Tipping, P.W. 2014. Specificity of Lepidelphax pistiae (Hemiptera: Delphacidae) to Pistia stratiotes (Araceae). Biocontrol Science and Technology. 24:485-488.2014. Interpretive Summary: Waterlettuce is one of the world's worst floating weeds and causes millions of dollars in damage to wetlands in the U.S. In most cases, herbicides are used to keep weed populations at a maintenance level but this requires perpetual applications of these chemicals to fresh water. A newly described planthopper, Lepidelphax pistiae, feeds exclusively on the plant in Argentina. Preliminary no-choice testing was done on this species to determine if it has potential as a biological control agent for waterlettuce. In all tests with plants in the same plant family as waterlettuce, as well as plants that are normally found growing in the same habitats in Florida, the planthopper did not survive or lay eggs. The exception was waterlettuce where the insects survived and laid many eggs which, in turn, completed development into adults. This indicates that further testing is warranted because it appears that this insect is likely to be very specific and feed only on waterlettuce. If this species is found to be host specific to waterlettuce, it may help reduce the populations of this weed so that less herbicide will be required to control this plant at maintenance levels in the U.S.
Technical Abstract: Pistia stratiotes (Araceae) is a serious weed in many waterways of the world. Lepidelphax pistiae is a recently described planthopper found on P. stratiotes throughout central and northern Argentina. No-choice feeding tests were conducted on 29 species of Araceae and various species that share the same wetland habitats with P. stratiotes in the U.S. In every test plant except P. stratiotes, nymphs and adults did not survive past 5-7 days and no progeny were produced. In contrast, survival was high on P. stratiotes and an average of 92.8 F1 adults were produced after exposing plants to 3 females and 2 males for 7 days. These preliminary results suggest that L. pistiae is monospecific to P. stratiotes and therefore may have potential as a classical biological control for this serious aquatic weed.