Pests herbivores

Allelopathic compounds act as repellents for herbivorous pests, so the same strategy used in weed control could be effective against pests and pathogens. Only allelopathy is not possible to use the complete control of weeds, pests or diseases it is necessary to combine it with other methods of plant protection. 

Yu SJ (1989) Purification and characterization of gluathione S-transferase from five phytophagous Lepidoptera. Pestic Biochem Physiol 35 97-105 Yu SJ (1992) Plant allelochemical-adapted glutathione transferases in Lepidoptera. In Mullin CA, Scott JG (eds) Molecular mechanisms of resistance to herbivorous pests to natural, synthetic and bioengineering control agents. Plenum, New York, pp 174-190 Yu SJ (1996) Insect glutathione S-transferases. Zool Stud 35 9-19... 

A large number of phytophagous beetles is economically important as pests on crops, forests, and stored products, and they are vectors of fungi and viral plant diseases. On the other hand, many species have beneficial functions in the detritus cycle, and carnivorous species may feed on herbivorous insects. 

Other aspects of implementing indirect volatile defenses, as recently discussed in several excellent reviews [17, 94, 95], will include the assessment of timing and synergy of volatile emissions with direct defense responses of the herbivore-damaged plant, especially if indirect defense strategies will be integrated with toxin-based pest control strategies. 

Turlings TCJ, Ton J (2006) Exploiting scents of distress the prospect of manipulating herbivore-induced plant odours to enhance the control of agricultural pests. Curr Opin Plant Biol 9 421-427... 

The effect of caffeine has been tested with insect herbivores. Tobacco horn-worms, Manduca sexta, die from a diet with 0.3% caffeine, and the beetle Calioso-bruchus chincnsis becomes sterile at a concentration of 1.5% (Nathanson, 1984). However, experiments showed that caffeine does not protect the coffee plant against the leaf miner Perileucoptera coffedla, one of the major pests of coffee (Filho and Mazzafera, 2000). 

Pheromones are classified in at least ten different categories. The most conq)lex category involves enantiomers at a specific composition (Mori 2000), implying multiple receptors. Other complex networks of biological events involve terpenoids released by plants in response to grazing by herbivores. These metabolites can be used to attract parasitic wasps for pest control (Tumlinson 1993), or, like the strigolactones (Table 12.1), as useful germination stimulants of root parasites of plants in the families Scrophulariaceae and Orobanchaceae (Welzel 1999 Ryan 2001). 

Bukovinszky, T., Trefas, H., van Lenteren, J.C., Vet, L.E.M. and Fremont, J. 2004. Plant competition in pest-suppressive intercropping systems complicates evaluation of herbivore responses. Agriculture Ecosystems and Environment 102 185-196. 

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