The influence of chemical constitution on the toxicity of organic compounds to wireworms

Abstract

1. The relationship between chemical constitution and toxicity to wireworms of organic compounds is found to be of a twofold nature.2. The general effect of a group of compounds of the same type is directly determined by the chemical constitution of the type. The particular effects of individual members of the groups are limited by their physical properties such as volatility etc., which may be regarded as indirect consequences of their chemical constitution.3. The aromatic hydrocarbons and halides are on the whole more toxic than the aliphatic hydrocarbons and halides. The groups that influence toxicity most when introduced singly into the benzene ring are in order of importance the methylamido (most effective), dimethylamido, hydroxy, nitro, amido, iodine, bromine, chlorine, methyl groups (least effective). But this order is modified in presence of another group; thus when there is a CH3 already present in the ring the order becomes chlorine (side chain), amido, hydroxy, chlorine (ring), methyl. Chlorine and hydroxy groups together give rise to highly poisonous substances considerably more effective than where present separately. The association of chlorine and nitro groups in chloropicrin gives rise to one of the most toxic substances tested. Methyl groups substituted in the amido group of aniline increase toxicity more than if substituted in the ring.

The Contact Toxicity of a Number of D.D.T. Analogues and of Four Isomers of Benzene Hexachloride to Macrosiphoniella San Born I and Oryzaephilus Surinamensis*

“…Thus toxicity towards insects has been related with boiling-point (Moore, 1g17a, b), vapour pressures (Tattersfield & Roberts, 1920), to the partition coefficient between oil and water (Tattersfield & Gimingham, 1g27), and to adsorption and surface activity (O'Kane, Westgate, Glover & Lowry, 1930). Ferguson (1939) correlated these results with those obtained in other fields and expanded the ideas involved and ma& them more precise in his concept of chemical potentials.…”

Fumigation against grain weevils with various volatile organic compounds /

“…Bromoform and monobromobenzene were found by Tattersfield and Roberts (24) to be moderately toxic to wireworms. Moore (14) tested the action on flies of bromobenzene, p-dibromobenzene, o-and p-bromotoluene, and bromoxylene.…”

“…Cyclohexane was twice as toxic as benzene. Tattersfield and Roberts (24) found that anthracene and phenanthrene were nontoxic to wireworms; that mesitylene, p-cymene, and naphthalene had marginal toxicity; and that n-pentane, ?i-hexane, n-heptane, benzene, toluene, and m-and^-xylene had low toxicity. Of the hydrocarbons examined only pseudocumene had moderate toxicity.…”

The solubility of some likely spray substances in solvents containing soap. The preparation of spraying emulsions

“…Tattersfield and Roberts, in a comprehensive survey of the toxicity of the vapours of organic substances to the very resistant wireworm (8), have also experimented on Journ. of Agrio.…”

“…These slow-creaming emulsions, therefore, must contain large amounts of oil in actual solution. 8 Private communication from the late Prof. Lefroy. 8 The writer has no definite knowledge on the costs of hydrogenated phenols (procured from R. W. Greeff and Co., London); hydrogenation should, however, be cheap; and usually demand for a chemical means that it becomes much cheaper.…”