The idea of using species-specific behavior-modifying chemicals for the management of noxious insects in agriculture, horticulture, forestry, stored products, and for insect vectors of diseases has been a driving ambition through five decades of pheromone research. Hundreds of pheromones and other semiochemicals have been discovered that are used to monitor the presence and abundance of insects and to protect plants and animals against insects. The estimated annual production of lures for monitoring and mass trapping is on the order of tens of millions, covering at least 10 million hectares. Insect populations are controlled by air permeation and attract-and-kill techniques on at least 1 million hectares. Here, we review the most important and widespread practical applications. Pheromones are increasingly efficient at low population densities, they do not adversely affect natural enemies, and they can, therefore, bring about a long-term reduction in insect populations that cannot be accomplished with conventional insecticides. A changing climate with higher growing season temperatures and altered rainfall patterns makes control of native and invasive insects an increasingly urgent challenge. Intensified insecticide use will not provide a solution, but pheromones and other semiochemicals instead can be implemented for sustainable area-wide management and will thus improve food security for a growing population. Given the scale of the challenges we face to mitigate the impacts of climate change, the time is right to intensify goal-oriented interdisciplinary research on semiochemicals, involving chemists, entomologists, and plant protection experts, in order to provide the urgently needed, and cost-effective technical solutions for sustainable insect management worldwide.

Recording of electroantennographic (EAG) responses from tsetse, Glossina pallidipes and G. morsitans morsitans (Diptera: Glossinidae) has been used to detect olfactory stimulants in volatiles from cattle. The most potent stimulant in cattle odours collected on Porapak resin has been identified as 1-octen-3-ol by gas chromatographic retention data and mass spectrometry. The rate of production of l-octen-3-ol by a normal ox was estimated to be 0.043 mghr" 1 , and the natural material was shown to be predominantly the (/?)-( -)enantiomer. No l-octen-3-ol was collected under the conditions used in the absence of an ox. EAG dose-response curves to l-octen-3-ol showed it to be about 10 6 times more potent than acetone, a known attractant for tsetse, with the maximum response of about 1 mV occurring to approx. 1 ng at source. l-Octen-3-ol caused increased upwind flight by tsetse in a wind tunnel bioassay, and in the field it was attractive to tsetse by itself and also increased the attractiveness of both ox odour and of mixtures of carbon dioxide and acetone.Resume-Les reponses electroantennographique (EAG) des mouches tse-tse, Glossina pallidipes et G. morsitans morsitans (Diptera: Glossinidae), ont ete notees afin de decouvrir les stimulants olfactifs parmi les composes volatils emanant du betail. Le stimulant le plus puissant dans l'odeur de betail, recueillie sur la resine Porapak, a ete identifie comme l-octen-3-ol en utilisant des donnees de retention chromatographique en phase gazeuse et spectrometrie de mass. On a estime le taux de production de l-octen-3-ol par un boeuf normal a 0,043 mghr" 1 et la matiere naturelle s'est revelee comme composee en majeure partie de l'enantiomere (R)- (-). Dans les conditions utilisees, on n'a recueillie de l-octen-3-ol qu'en presence d'un boeuf. Les courbes de dosage-reponse EAG pour l-octen-3-ol l'a revele a peu pres 10 6 fois plus puissant que l'acetone, un attractant connu pour les mouches tse-tse, la reponse maximum d'environ 1 mV etant enregistree pour environ 1 ng a la source. l-Octen-3-ol a occasionne un accroissement de vol des mouches tse-tse contre le vent dans un tunnel aerodynamique. Sur le terrain l-octen-3-ol s'est reveje attractif tout seul et a augmente la puissance attractive de l'odeur de boeuf et aussi des melanges de bioxyde de carbone et d'acetone.

Human sweat samples were chemically fractionated into acid and non-acid components. The most abundant volatile compounds present in the fractions were identified by linked gas chromatography mass spectrometry. The acid fractions were found to be composed of a range of twenty aliphatic and three aromatic carboxylic acids ranging, on average, from 0.02 to 20 micrograms per ml of sweat sampled. Non-acid fractions were found to contain: 6-methyl-5-hepten-2-one, 1-octen-3-ol, decanal, benzyl alcohol, dimethylsulphone, phenylethanol, phenol and 4-methylphenol, collectively amounting to 0.1 and 3 micrograms per ml of sweat. The major component of sweat was found to be L-lactic acid which constituted from 1 to 5 mg/ml. Using the intact antennae of the anthropophilic malaria vector mosquito Anopheles gambiae Giles, the peripheral olfactory activities of compounds identified in the sweat fractions were investigated by electroantennography (EAG). Short-chain saturated carboxylic acids, methanoic, ethanoic, propanoic, butanoic, pentanoic and hexanoic acids were found to elicit significantly larger EAG responses than longer chain saturated carboxylic acids from female An.gambiae. For a given dose the largest amplitude EAG response was elicited by methanoic acid. Pentanoic acid elicited larger EAG responses than either butanoic or hexanoic acids. Two non-acidic compounds, 1-octen-3-ol and 4-methylphenol, were found to elicit significant dose-dependent EAG responses from female An.gambiae. 1-Octen-3-ol elicited larger EAG responses than 4-methylphenol for a given dose, but both compounds elicited smaller EAG responses than the same dose of C1-C6 straight-chain aliphatic carboxylic acids. The possible behavioural significance of the EAG-active compounds identified in human sweat samples is discussed.

The attractiveness of cattle urine to Glossina morsitans morsitans Westwood and G. pallidipes Austen was shown to be entirely attributable to the phenolic components which it contains. Four of the eight naturally occurring phenol derivatives (3- and 4-methylphenol, 3-ethylphenol and 3-n-propylphenol) were electroantennographically active, induced upwind flight in wind-tunnel bioassays and increased trap catches in field tests in Zimbabwe. One of the minor components, 2-methoxyphenol, had little antennographic activity but induced upwind flight in the wind-tunnel and appeared to be repellent in field tests.