Use in pest control

This is not a complete review of the literature of naturally occurring substances that are being or may be used in pest control. Excellent reviews cover well the older literature of natural insect at-tractants (9, 32, 37, 40, 41, 43, 44, 71) and repellents (7, 17, 22, 25, 54, 63, 64). Only the more important recent developments in this field are discussed here. I hope that this report will stimulate the increased interest and investigation on the part of both chemists and entomologists, working together, that is needed to make the concept a reality. 

Genna, R. L., Mordue, W., Pike, A. W., and Mordue (Luntz) A. J. (2004). Identification of semiochemicals involved in sea lice host location, and their potential use in pest control. In Annual Meeting of the International Society ofChemical Ecology, July 2004, Ottawa, Canada. 

Sex pheromones, chemicals that attract one sex of an insect to the other, also have uses in pest control. They are often utilized with traps to monitor the number of pest insects in an area, and when applied in the field at higher levels, they can disrupt reproduction or egg laying. 

As the name implies, this group of insecticides used in water-soluble formulations easily dissolves in water. In this formulation, the technical-grade material is a finely ground solid. It can be added to the spray tank, where it dissolves quickly. Once dissolved, an SP becomes an invisible solution that can be applied to approved surfaces without constant agitation. The most common SPs used in pest control are Acephate Turf and Acephate PCO Pro (Orthene) concentrates. 

More recently, Mota-Sanchez et al. (2002) found a similar trend using database analysis. Table 10.3 shows that the majority of reported cases of resistance are arthropod resistance to organophosphate (44%) and organochlorine (32%) insecticides. It is understandable, because these two classes of insecticides have been used in pest control for over half a century. As shown in Table 10.4, twelve species of insects have developed resistance to various strains of Bt and Bt toxins in the laboratory and/or the field. 

There are practical demands for the invention of pheromone mimics, because pheromones are often too labile to be used in pest control. Various mimics have been prepared to date, several of which will be described in this section. 

Oxidative -demethylation is a pathway involved in the metabolism of some amide-substituted organophosphates. Dicrotophos is A-demethylated to monocrotophos via the iV-methylol derivative [156,157]. Monocrotophos, itself an active inhibitor of cholinesterase used in pest control, is further A-demethylated to its iV-methylol and finally to the unsubstituted amide [157]. This latter step is of only minor significance [158]. The principal degradative metabolite of dicrotophos, dimethyl phosphate, produced by hydrolysis of the vinyl-phosphate linkage was found to exceed the production of 0-demethylmonocrotophos by a ratio of approximately 4 lwhile only trace amounts of the iV-demethylated metabolite were detected [158]. 

Behavioral Chemicals — Semiochemicals. Semiochemicals are chemicals emitted by plants or animals that modify the behavior of receptor organisms of the same or different species. This definition includes pheromones, allomones, and kairomones. The sex-attractant pheromones are emitted by the female to attract the male for mating purposes and they have been used in pest control in the following ways (11) ... 

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