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ARS Home » Southeast Area » Stoneville, Mississippi » Biological Control of Pests Research » Research » Publications at this Location » Publication #426894
Research Project: Substainable Management of Invasive Pest Ants

Location: Biological Control of Pests Research

Title: Toxicity and repellency of baccharis essential oils and selected pure compounds against mosquitoes (diptera:culicidae) and hybrid imported fire ants (hymenoptera: formicidae

Author
item ALI, ABBAS - University Of Mississippi
item MANFRON, JANE - State University Of Ponta Grossa
item MONTEIRO, LUCIANE - State University Of Ponta Grossa
item DE ALMEIDA, VALTER - State University Of Ponta Grossa
item RAMAN, VIJAYASANKAR - University Of Mississippi
item KHAN, IKHLAS - University Of Mississippi

Submitted to: Journal of Xenobiotics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2023
Publication Date: 10/27/2023
Citation: Ali, A., Manfron, J., Monteiro, L.M., De Almeida, V.P., Raman, V., Khan, I.A. 2023. Toxicity and repellency of baccharis essential oils and selected pure compounds against mosquitoes (diptera:culicidae) and hybrid imported fire ants (hymenoptera: formicidae. Journal of Xenobiotics. 2023, 13(4), 641-652.
DOI: https://doi.org/10.3390/jox13040041

Interpretive Summary: Insect disease vectors like Aedes aegypti (L.) and Ae. albopictus (Skuse) are the primary and secondary vectors of Zika and dengue as well as other viruses. The use of synthetic insecticides in mosquito control has proven to be one of the major approaches for preventing and reducing mosquito-borne disease incidence. Insect repellents prevent mosquitoes from biting humans and are used against host-seeking vectors for immediate and localized personal protection. Red imported fire ants are important agricultural, medical, and urban pests throughout the southeastern United States and parts of western states. Management of imported fire ants is usually accomplished with chemical treatment of individual mounds using baits or traditional contact insecticides. Baccharis L. is an important genus in the Asteraceae family, comprising about 435 species distributed from Argentina to the United States. Compounds from essential oils of Baccharis species are reported to have anti-inflammatory, antibacterial, antifungal, antiprotozoal, antiviral, antimalarial, and insecticidal properties. The present study was conducted to determine the repellency and toxicity of Baccharis spp. essential oils and their pure compounds against Aedes aegypti, and hybrid imported fire ants. Biting deterrence of essential oils of Baccharis spp. and their two pure compounds were similar to DEET against mosquitoes. Similarly, B. microdonta essential oil, spathulenol and kongol were toxic to mosquito larvae. Essential oil of B. microdonta showed both repellency and toxicity against imported fire ant workers. Results from these data suggest that these essential oils can be used as toxicants and deterrents/repellents against mosquitoes and imported fire ants.

Technical Abstract: As part of our ongoing natural products screening program, we regularly screen new materials for their toxicity and repellency against mosquitoes and other insects. In this study, we tested essential oils from five species of Baccharis for their toxicity and repellency/biting deterrence against mosquitoes and imported fire ants. Biting deterrent activity of essential oils of B. microdonta and B. punctulata at 10 µg/cm2 was statistically similar to DEET at 25 nmoL/cm2, whereas essential oils of B. pauciflosculosa, B. sphenophylla and B. reticularioides showed activity significantly lower than DEET against mosquitoes. Two major compounds from the active essential oils, kongol and spathulenol, also exhibited biting deterrent activity similar to DEET at 25 nmoL/cm2 against mosquitoes. Baccharis punctulata essential oil with LC50 of 20.4 ppm showed the highest toxicity. The toxicity of B. pauciflosculosa (LC50 = 31.9 ppm), B. sphenophylla (LC50 = 30.8 ppm), B. microdonta (LC50 = 28.6 ppm), and kongol (LC50 = 31.9 ppm) were similar. Spathulenol showed LC50 of 48.7 ppm, whereas B. reticularioides essential oil (LC50 = 84.4 ppm) showed the lowest toxicity. Hybrid imported fire ant workers removed significantly less sand at dosages of 156, 78 and 39 µg/g than the solvent control. In contrast, the removal of sand at the dose of 19.5 µg/g was similar to solvent control as well as DEET treatment. Baccharis microdonta essential oil showed larvicidal activity against imported fire ants having LC50 of 136.5 (108.2 - 174.3) µg/g, whereas permethrin with LC50 of 2.74 µg/g was active at a much lower dose at 24-h post-treatment. This is the first report of the toxicity and repellency of the essential oils of these five species of Baccharis and kongol against mosquitoes and B. microdonta against hybrid imported fire ant workers.