Journal of the American Mosquito Control Association (2015) 31, 375-379

Isik Unlu, Paul T. Leisnham, Gregory M. Williams, Kim Klingler, Garrett W. Dow, Nicole Kirchoff, Sophie Jin, Nicholas Delisi, Katherine Montenegro and Ary Faraji (2015)
Effects of a red marker dye on Aedes and Culex larvae: Are there implications for operational mosquito control?
Journal of the American Mosquito Control Association 31 (4), 375-379
Abstract: Marker dyes are often mixed with liquid insecticide formulations prior to field applications to accurately determine the characteristics and penetration of droplets into targeted habitats. We have been using FDandC Red 40 Granular DM food dye at the rate of 20 g/liter in liquid solutions of Bacillus thuringiensis israelensis (Bti) for area-wide larvicide applications against the Asian tiger mosquito, Aedes albopictus. The Bti and dye mix ratio has been recommended by pesticide manufacturers for testing under operational conditions, but no data exist on the effects of the dye itself on mosquito larvae. We tested the effects of the FDandC Red 40 food dye in laboratory bioassays against different strains of Ae. albopictus (New Jersey and Maryland) and Culex pipiens pipiens (Utah) at rates of 0.039 to 80.0 g/liter. We also conducted field application trials to measure dye concentrations up to 100 m downwind when mixed and applied according to manufacturer instructions. In laboratory bioassays, we found that mean survival in cups with dye were significantly different from the controls beginning at 10.0 g/liter for New Jersey Ae. albopictus and at 20.0 g/liter for Maryland Ae. albopictus and Utah Cx. p. pipiens. In field application trials, we recorded a maximum volume density of 1,152.8 nl/cm² and calculated the maximum concentration of dye at 9.09 × 10^-3 g/liter. Our results showed that although we detected greater effects of dye on Ae. albopictus in New Jersey experiments than Ae. albopictus in Maryland and Cx. p. pipiens from Utah, concentrations of the dye during operational applications were at least 1,100 times below concentrations that exhibited toxic effects for either species in the laboratory, suggesting that the dye will not interfere with accuracy of field bioassays. Our results conclusively demonstrate that the addition of the FDandC Red 40 marker dye does not alter the efficacy of the pesticide formulation by skewing results, but rather provides a valuable addition to accurately determine pesticide penetration and spectrum by discriminating between intended pesticide and other potential pollutants.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Ary Faraji

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Culex pipiens		U.S.A. (SW)
	Aedes albopictus		U.S.A. (NE)
Bacillus thuringiensis var. israelensis (entomopathogen)	Aedes albopictus