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Insects cause extensive damage to stored grains and their value added products. Among the stored grain pests Sitophilus oryzae (L.) Callosobruchus chinensis (Fab.) and Tribolium castaneum (Herbst.) are considered as destructive pests in India. Plants may provide alternatives to currently used insect control agents as they constitute rich source in bioactive molecules. Lantana camara, an erect shrub, which grows widely in the tropics, exhibits insecticidal activity against several insects. The methanol extract from leaves of L. camara has fumigant and contact toxicity against S. oryzae, C. chinesis and T. castaneum. In fumigant assays, The LC 50 for S. oryzae was 128 μl/L 1 , C. chinensis 130.3 μl/L 1 , and T. castaneum 178.7 μl/L 1 . The LD 50 values for S. oryzae C. chinensis and T. castaneum in contact toxicity were 0.158, 0.140 and 0.208 mg/cm 2 , respectively. For grain treatment, a concentration of 500 mg/L 1 and 7 days exposure were needed to obtain 90 -100 % population extinction in all three insects. Probit analysis showed that C. chinensis were more susceptible than S. oryzae and T. castaneum. Gaschromatography-Mass Spectrometer (GCMS) studies for extracts indicated the presence of potent fumigant molecules in L. camara. The prospect of utilizing L. camara as potent fumigant insecticide is discussed.

Autodetection is an olfactory behavioural process where the females of some species respond to their own pheromonal blends. Through electroantennogram studies it has been proved that the gravid females of Helicoverpa armigera (Hubner) respond to their pheromone blend consisting of Z-11-hexadecenal and Z-9-hexadecenal in the ratio 97 : 3. Male antennae respond more strongly than virgin female antennae. However, antennae of gravid females elicit strong response than unmated males. Also, males showed strong responses in cross-wind flying in wind tunnel experiments, when sex pheromone blends were used. Virgin females and gravid females showed poor response in wind-tunnel studies. The ovipositional experiment where gravid females were allowed to oviposit in the presence and absence of pheromone odours indicated that there was no difference in the number of eggs laid. Through morphological studies, it has been proved that the females also possess sensilla trichoidea, destined to perceive the pheromone blends, though lesser in number than the males. These results support the hypothesis that autodetection of sex pheromones exists in females of H. armigera and is thought to function as a mechanism to induce dispersal under high population densities.

Plants produce a wide range of organic compounds like sugars, organic acids and vitamins, which can be used as nutrients or signals by microbial populations. On the other hand, microorganisms release phytohormones, enzymes, which may act directly or indirectly to activate plant immunity and regulate plant growth. Plant signalling molecules such as auxin and cytokinin can be produced by microorganisms to colonize efficiently with roots and enhance root activity. The isolated microbe Bacillus aryabhattai, has the ability to produce1-aminocyclopropane-1-carboxylate (ACC) deaminase to lower plant ethylene level, often a result of various stresses, and is found to be a key component in the efficacious functioning of this bacterium. The optimal functioning of this bacterium includes the synergistic interaction between ACC deaminase, and plant with bacterial indole-3-acetic acid (IAA).

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