Acute toxicity of mosquito pesticides on weed biological control agents in south Florida, USA

ABSTRACT

Mosquito pesticides effectively control vectors of human disease but have numerous unintended consequences. These may include adversely affecting non-target species such as weed biological control agents. Acute toxicity of two mosquito pesticides, naled and permethrin, was studied on three biological control agents released against invasive weeds in south Florida. These were the biological control agent Oxyops vitiosa of melaleuca, Melaleuca quinquenervia, the agent Neomusotima conspurcatalis for Old World climbing fern, Lygodium microphyllum, and the agent Lilioceris cheni for air potato Dioscorea bulbifera. We calculated LD₅₀ values for both pesticides on early and late instars for each herbivore species. The air potato herbivore, L. cheni was the most sensitive species tested and all three species were more sensitive to the pesticide permethrin than naled. These results indicate that even low concentrations of these products can have a detrimental effect on these weed biological control agents. The unintended consequences of mosquito adulticide applications should be considered when evaluating biological control agent impacts.

KEYWORDS:

• Lilioceris cheni
• Neomusotima conspurcatalis
• Oxyops vitiosa
• permethrin
• naled

Acknowledgements

We thank Evan Broggi and James Murphy USDA/ARS, Ft Lauderdale, FL for technical assistance. Mention of trade names or commercial products in this article is solely for the purpose of providing information and does not imply any recommendation or endorsement by the U.S. Department of Agriculture. U.S. Department of Agriculture is an equal opportunity employer.

Disclosure statement

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

Additional information

Funding

Partial funding was generously provided by the Comprehensive Everglades Restoration Plan.