Topical and Vapor Toxicity of Saturated Fatty Acids to the German Cockroach (Dictyoptera: Blattellidae)

Abstract

Topical and fumigant toxicity of saturated aliphatic fatty acids with chain lengths of C1 through C14 were determined against the German cockroach, Blattella germanica (L.). In the C1 to C11 series, topical toxicity (LD50 in milligram per adult male) ranged from 0.145 (C1) to 0.322 mg (C2). Toxicity declined dramatically with C12 and C14 acids whose LD50 values could not be calculated. The relative fumigation toxicity (LC50 in microliter per liter) of C1 through C5 acids was positively correlated with topical toxicity with values ranging from 6.159 (C3) to 12.302 microl/liter (C2). Fumigant toxicity decreased sharply with C6 (LC50 = 37.691 microl/liter) and there was no mortality of cockroaches exposed to vapors from C7 to C14 acids. The low fumigant toxicity of the C6 to C11 acids was correlated with their relatively low vapor pressure, but differences in diffusion of the vapors into the spiracles and subsequent passage to the target sites may have also been involved.

Synthetic and Natural Insecticides: Gas, Liquid, Gel and Solid Formulations for Stored-Product and Food-Industry Pest Control

“…Some botanical oils [ 69 ], petrol oils [ 436 ], and silicone (organosilicone) polymer surfactants [ 438 , 439 , 440 ] have been tested with promising results as direct sprays [ 306 ] on urban or storage arthropods. Various fatty acid salts, soaps, and surfactants showed insecticide activity against German cockroaches in laboratory settings [ 441 , 442 ]. However, fatty acid salt liquids (1%–2%) were effective in killing B. germanica and P. americana cockroaches only when the insects were thoroughly wetted [ 441 ].…”

Behavioral response ofPanonychus citri(McGregor) (Acari: Tetranychidae) to synthetic chemicals and oils

“…By contrast to synthetic chemicals, plant-based derivatives (such as vegetable oils) are used as alternatives (Flamini, 2003) due to their compatibility with non-target organisms, low toxicity, negligible resistance development, and eco-friendly (Marcic, 2012). Fatty acids that are significant vegetable oil components are active ingredients that increase their toxicity against pests (Baldwin, Koehler & Pereira, 2009;Sims et al, 2014). Linoleic acid that is an important component of vegetable oil resulted in attractive responses (Rollo, Czyzewska & Borden, 1994;Buehlmann et al, 2014), as P. citri found on treated surfaces (at LC 50 ) after 24 h in this study.…”

Chemical composition and acaricidal activity of seed oils of the palms Mauritia flexuosa and Mauritiella armata in Rhipicephalus microplus (Ixodidae)

“…Saturated and unsaturated fatty acids with antioxidant activity can be identified in fixed oils extracted from the fruits of both palm trees, such as palmitoleic acid, linoleic acid, palmitic acid, and myristic acid. Chromatographic analyses have been revealed that vegetable oils are biologically active against arthropod pests (Sims et al, 2014). Although the effect of fatty acids against arthropods is not yet known, the toxicity of these compounds increases with the length of the carbon chain, as well as, the presence of certain chemical bonds (i.e.…”

“…Although the effect of fatty acids against arthropods is not yet known, the toxicity of these compounds increases with the length of the carbon chain, as well as, the presence of certain chemical bonds (i.e. saturated or unsaturated) (Sims et al, 2014).…”