Effects of invasive plant haplotypes on a biological control agent (Lepidelphax pistiae) fecundity and impact

ABSTRACT

Pistia stratiotes L. is an invasive floating plant that alters native habitats in Florida by forming thick mats that shade out submerged vegetation and obstruct navigation. Multiple genotypes of this plant have been identified from locations across its native and adventive ranges including types from throughout the Americas, the Caribbean, Asia, and Australia. We investigated the performance of a known monophagous insect, Lepidelphax pistiae, on nine P. stratiotes haplotypes (from four clades) in no-choice experiments and found that while L. pistiae performance varied on different haplotypes, there was considerable overlap in fitness and impact among haplotypes. Lepidelphax pistiae did not distinguish between purported ‘native’ and ‘non-native’ haplotypes and did not perform better or cause more damage to South American haplotypes specifically, which would have supported its utility as a biocontrol agent on the exotic haplotypes found in Florida. While L. pistiae is monophagous on P. stratiotes, it was not specific enough to differentiate consistently among the tested haplotypes and thus, may not be suitable as a biological control agent because of the potential threat they pose to native haplotypes of P. stratiotes in Florida.

KEYWORDS:

• Pistia stratiotes
• Lepidelphax pistiae
• waterlettuce
• biological control agent
• haplotypes

Acknowledgements

The authors thank Scott Goldstein at the Invasive Plant Research Laboratory for his assistance with this experiment. The authors acknowledge the Florida Fish and Wildlife Conservation Commission and the Fish and Wildlife Research Institute for allowing this work to be completed. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture (USDA).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, ABCG, upon reasonable request.