Control of insect pests

In yet another application of plant virus peptide presentation systems, Borovsky [52] used TMV to present a peptide, trypsin modulating oostatic factor (TMOF), that terminates trypsin biosynthesis in the mosquito gut and causes larval mortality. This unique study uses plant virus particles for the biological control of insect pests. 

Synthetic pyrethroids now account for at least 30% of the world insecticide market and are rapidly replacing other agricultural chemicals for control of insect pests. Fenvalerate is one of the more widely used synthetic pyrethroid insecticides. It is derived from a combination of a-cyano-3-phenoxybenzyl alcohol and a-isopropyl phenylacetate ester. Technical fenvalerate is a mixture of four optical isomers, each occurring in equal amounts but with different efficacies against insect pests. Fenvalerate does not usually persist in the environment for >10 weeks, and it does not accumulate readily in the biosphere. Time for 50% loss (Tb 1/2) in fenvalerate-exposed amphibians, birds, and mammals was 6 to 14 h for reptiles, terrestrial insects, aquatic snails, and fish it was >14 h to <2 days and for various species of crop plants, it was 2 to 28 days. Fenvalerate degradation in water is due primarily to photoactivity, and in soils to microbial activity. Half-time persistence in nonbiological materials is variable, but may range up to 6 days in freshwater, 34 days in seawater, 6 weeks in estuarine sediments, and 9 weeks in soils. 

Bedding RA. Low cost in vitro mass production of Steinernema( = Neoaplectana) and Heterorhabditis species (nematoda) for field control of insect pests. Nematolog. 1981 27 109-114. 

As knowledge of the control of insect pests and diseases in the tropics is increased, the growing season of basic food crops can be lengthened and almost cer-... 

In general, the control of insect pests of cacao has been neglected. Also, little is known regarding the effect of insecticides on cacao. Cardona (9) in Colombia has studied the influence of some insecticides on the pollination and fruit setting. He used various preparations of BHC Agrocide, chlordan, DDT, dieldrin, dieldrex, methoxychlor [l,l,l-trichloro-2,2-bis(p-methoxyphenyl) ethane], and toxaphene. 

The avermectins, a family of compounds with potent anthelmintic, insecticidal and acaricidal activity, have vividly demonstrated that fermentation products can have entirely unanticipated activities. Besides their utility in animals, they show great promise for the control of insect pests of plants. Although antibiotics have found only a limited role in the control of plant diseases, the desire to find environmentally acceptable alternatives to the chemicals currently used has prompted new research efforts to discover fermentation products for use as pesticides. 

F. J. Ritter and C. J. Persoons, Isolation and Identification of Pheromones Integrated Control of Insect Pests in the Netherlands, p. 203. Pudoc, Wageningen, 1980. 

A better understanding of the role of phytoalexins in plant defenses and of the mechanisms of induced resistance may potentially open a powerful new approach to the control of insect pests of cultivated plants. If indeed, in light of the hypothesis of optimal defense strategies (3), a post-attack response is a more efficient line of defense than the attack-independent accumulation of allelochemics, the exploitation of phytoalexin-producing mechanisms may represent a fertile field for future investigations. Several uses of induced resistance may be conceived. Four of these approaches are briefly discussed. 

The main entomopathogens are Verticillium lecanii for control of aphids, white fly and thrips, Beauveria bassiana and B. brongniartii for control of lepidopteran and coleopteran species and Metarhizium aniso-pliae and M. flavoviride for control of insect pests of coffee and sugar cane and, more recently, to control locust swarms. 

Salt, G. (1958). Parasite behaviour and the control of insect pests. Endeavour 17 145-148. 

This article provides general information on many aspects of the chemical control of insect pests as developed during the twentieth century. It summarizes the chemistry, properties, uses, and advantages and disadvantages of most of the chemicals used for insect control, including many products of largely historical interest as well as some not registered for use in the United States but used elsewhere in the wodd (11—18). 

In the remaining pages I shall discuss in greater detail the NPVs and their applications in biological control of insect pests. These viruses have been studied intensively during the... 

This chapter describes the application of animal cells, particularly insect cells, for baculovirus production and its use as a bioinsecticide. The use of baculovirus in the control of insect pests and its production in vitro are discussed. 

Although pheromone traps are now widely used for monitoring insect populations, the use of synthetic pheromones in control of insect pests by disruption of pheromone-mediated communication has been much slower to develop, at least in part because of the difficulties of formulation. There are three main types of formulation currently available - hollow fibres, plastic laminates and microcapsules. For several years, the UK Overseas... 

Development Administration and ICI Ltd. have been involved In a collaborative project to develop microencapsulated formulations of lepidopterous sex pheromones for control of insect pests by mating disruption. 

A variety of pesticides have been in use for many decades for the control of insect pests of agricultural crops and storehouses and as vectors of communicable diseases. Human exposure to pesticides during mixing, spraying, transportation, and waste disposal has become common. Prevention of inhalation and dermal absorption of... 

When B. thuringiensis was first used for pest control, it was hoped that insects would not develop resistance to these toxins because B. thuringiensis and insects have apparently coevolved. However, starting in the mid-1980s, a number of insect populations fiom several different species were shown to have the capacity to develop resistance to Cry toxins under laboratory and field conditions [159,160]. Development of resistance to Cry toxins in the field poses the most serious threat to the continued use of this novel agent for control of insect pests. 

The chemical control of insect pests dates back thousands of years. The earliest insecticides were inorganic compounds of copper, lead, and arsenic, as well as some naturally occurring organic compounds such as nicotine (Fig. 7.30a). Few of these first-generation insecticides are in use today because of their adverse side effects on plants, animals, and humans. 

Firstly, it is intrinsically lethal to some pest species, but is not particularly harmful to benchcials. Secondly, alone or in conjunction with other toxins, it cun affect inseel development. These efleets have potentially profound implications for the control of insect pests, particularly when allowed to express them-... 

Piperonyl hu 10Aide (PBO) is primarily used as a synergist in combination with natural pyrethrins or pyrethroids in space spray, residual and admixture products for the control of insect pests in or around domestic and commercial premises, especially food preparation areas. The suitability of PBO for (his purpose has been proven over many decades of study and widespread practical use. The main attributes oflhe compound which have ensured this long-las ting utilization in urban pest control procedures are summarized below. The beneficial effect that PBO has on insects showing resistance to insecticides is referred to in Chapters 12, 13 and 19 of this volume. 

Products based on synergized pyrethrins offer the physician, fanner, pet owner and veterinarian safe and effective control of insect pests without the inclusion of toxic additives, and without restrictions on repeat treatments. Since PBO is not a cholinesterase inhibitor, it may be used in conjunction with flea or tick dips, collars and oral medications. 

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