Semiochemicals and date palm IPM: an overview

Chemical signals play an important role in the survival of insects, and is being increasingly exploited as an IPM tool. Semiochemicals are organic compounds used by insects to convey specific chemical messages that modify insect behavior or physiology and are species specific and harmless to the environment. These chemicals are essential for pest survival including location of habitat, food and mates. Semiochemicals which mediate interactions among individuals of the same species (intra-specific reactions) are called pheromones, while those that mediate interactions among individuals of different species (inter-specific interactions) are known as allelo chemicals. It has been possible to identify chemical signals/cues for thousands of insect species. Most identified insect pheromones are from the orders Lepidoptera and Coleoptera. Sex pheromones are used to successfully control lepidopteran insects while aggregation pheromones have been developed to control coleopteran pests. Effective attractants, pheromones, repellents and/or host volatiles are known only for some of the major date palm pests viz., lesser date moth Batrachedraa mydraula, greater date moth Aphomia (= Arenipses) sabella, Indian meal moth Plodia interpunctela, raisin moth Cadra (= Ephestia) figulilella, carob moth Spectrobates (= Ectomyelois) ceratoniae, red palm weevil Rhynchophorus ferrugineus, rhinoceros beetle Orytes elegans, dried fruit beetle Carpophilus hemipterus, etc. This paper gives an overview on the use of semiochemicals in date palm IPM with emphasis on red palm weevil.