Essential insecticidal effect

Konstantopoulou, I., L. Vassilopoulou, P. Mavragani-Tsipidou, and Z. G. Scouras, 1992. Insecticidal effects of essential oils. A study of the effects of essential oils extracted from eleven Greek aromatic plants on Drosophila auraria. 48 616-619. 

Regnault-Roger C, Hamraoui A, Holeman M, Theron E, Pinel R (1993) Insecticidal effect of essential oils from Mediterranean plants upon A. obtectus Say (Coleoptera, Bmchidae), a pest of kidney bean Phaseolus vulgaris L.). J Chem Ecol 19 1231-1242... 

Mateeva A, Karov S (1983) Studies on the insecticidal effect of some essential oils. Nauchni Tmdove-Vissha Selskostopanski Institute Vasil Kolarov Plodiv, 28 129-139... 

Malaria affects an estimated 270 million people and causes 2—3 million deaths annually, approximately one million of which occur in children under the age of five. While primarily an affliction of the tropics and subtropics, it has occurred as far north as the Arctic Circle. The disease essentially has been eradicated in most temperate-zone countries, but some 1100 cases of malaria in U.S. citizens returning from abroad were reported to the Centers for Disease Control during 1990. Malaria is seen today in Southeast Asia, Africa, and Central and South America. It is on the increase in Afghanistan, Brazil, China, India, Mexico, the Philippines, Sri Lanka, Thailand, and Vietnam. Escalation of the disease is because of the discontinued use of the insecticide DDT which effectively kills mosquito larvae, but has been found to be toxic to Hvestock and wildlife. Also, chloroquine (6), a reUable dmg for the prophylaxis and treatment of falcipamm malaria, is ineffective in many parts of the world because of the spread of dmg-resistant strains. 

Many of the sulfur compounds are toxic but essential for life. The gas from elemental sulfur and from most of the compounds of sulfur is poisonous when inhaled and deadly when ingested. This is the reason that sulfur compounds are effective for rat and mice extermination as well an ingredient of insecticides. Sulfa drugs (sulfanilamide and sufadiazine), although toxic, were used as medical antibiotics during World War II before the development of penicillin. They are still used today in veterinary medicine. 

Whenever applied, IPM practices have consistendy resulted in decreases in insecticide applications of 50 to 90% over conventional spray programs. By encouraging natural enemies, IPM practices markedly decrease the rigor of natural selection by pesticides that is responsible for resistance. Natural enemy preservation also prevents the great fluctuations and suiges in insect pest populations observed after the injudicious use of broad-spectrum insecticides. Under the IPM concept, insecticides are generally used when other practices are inadequate and the pest population reaches the economic threshold. In order to make the IPM concept effective, insecticides must be used as selectively as possible, with minimal disturbance to all other elements of the ecosystem. Thus IPM practices are essentially blueprints for the proper use of insecticides in insect pest control. 

Insecticide management is concerned with the safe, efficient, and economical handling of insecticides during manufacture, utilization, and disposal. The essential components are selection of the proper insecticide for the IPM program, selection of the mode, timing, and dosage of application, consideration of the problems of resistance and resurgence, the possible effects of insecticide residues on food crops, and in the environment, and the impact of these on humans, domestic animals, and wildlife (7,9). 

These insecticides range from completely water-miscible compounds to essentially insoluble ones, as indicated in Table VI. Most highly water-soluble insecticides are systemic, that is, they are absorbed into the tissues of the growing crop, either through the leaves or through the roots. But some water-miscible compounds are so unstable that their toxicity is destroyed before systemic activity can be observed (12,18). Tepp, for example, has a half life in water of only 8 hours. While many other compounds in this class have only limited solubility in water, they are still effective systemics. Examples are demeton, methyl demeton, and phorate. 

T(he increasing development and use of insecticides and other pesticides constitute a growing hazard for contaminating our water supplies. To keep pace with the use (5,6) of these toxicants, more information is needed on distribution, transport, exchange mechanism, degradation products, and metabolites of these substances. Thus, convenient and sensitive methods of analysis are essential to the success of research in this field. Furthermore, pesticide levels in water can be monitored more accurately by improved analytical techniques. Accurate and rapid procedures are especially needed when prompt information or action is necessary. Even when low concentrations of pesticides do not show immediate adverse effects, detrimental results may eventually occur, since it has been observed that a number of these toxicants are concentrated in a variety of aquatic plants and animals. 

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